提交 · 148b50b769a76d95d98d62f3f159c286ec9083f8 · openeuler / raspberrypi-kernel

27 12月, 2019 14 次提交

mm: Ignore cpuset enforcement when allocation flag has __GFP_THISNODE · 148b50b7

由 Anshuman Khandual 提交于 5月 13, 2019

euler inclusion
category: feature
bugzilla: 11082
CVE: NA
-------------------

__GFP_THISNODE specifically asks the memory to be allocated from the given
node. Not all the requests that end up in __alloc_pages_nodemask() are
originated from the process context where cpuset makes more sense. The
current condition enforces cpuset limitation on every allocation whether
originated from process context or not which prevents __GFP_THISNODE
mandated allocations to come from the specified node. In context of the
coherent device memory node which is isolated from all cpuset nodemask
in the system, it prevents the only way of allocation into it which has
been changed with this patch.
Signed-off-by: NAnshuman Khandual <khandual@linux.vnet.ibm.com>
Signed-off-by: Nzhong jiang <zhongjiang@huawei.com>
Signed-off-by: NLijun Fang <fanglijun3@huawei.com>
Reviewed-by: Nzhong jiang <zhongjiang@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

148b50b7

mm: Enable Buddy allocation isolation for CDM nodes · 8877e9e4

由 Anshuman Khandual 提交于 5月 13, 2019

euler inclusion
category: feature
bugzilla: 11082
CVE: NA
-------------------

This implements allocation isolation for CDM nodes in buddy allocator by
discarding CDM memory zones all the time except in the cases where the gfp
flag has got __GFP_THISNODE or the nodemask contains CDM nodes in cases
where it is non NULL (explicit allocation request in the kernel or user
process MPOL_BIND policy based requests).
Signed-off-by: NAnshuman Khandual <khandual@linux.vnet.ibm.com>
Signed-off-by: Nzhong jiang <zhongjiang@huawei.com>
Signed-off-by: NLijun Fang <fanglijun3@huawei.com>
Reviewed-by: Nzhong jiang <zhongjiang@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

8877e9e4

mm: Change generic FALLBACK zonelist creation process · 023d1127

由 Anshuman Khandual 提交于 5月 13, 2019

euler inclusion
category: feature
bugzilla: 11082
CVE: NA
-------------------

Kernel allocation to CDM node has already been prevented by putting it's
entire memory in ZONE_MOVABLE. But the CDM nodes must also be isolated
from implicit allocations happening on the system.

Any isolation seeking CDM node requires isolation from implicit memory
allocations from user space but at the same time there should also have
an explicit way to do the memory allocation.

Platform node's both zonelists are fundamental to where the memory comes
from when there is an allocation request. In order to achieve these two
objectives as stated above, zonelists building process has to change as
both zonelists (i.e FALLBACK and NOFALLBACK) gives access to the node's
memory zones during any kind of memory allocation. The following changes
are implemented in this regard.

* CDM node's zones are not part of any other node's FALLBACK zonelist
* CDM node's FALLBACK list contains it's own memory zones followed by
  all system RAM zones in regular order as before
* CDM node's zones are part of it's own NOFALLBACK zonelist

These above changes ensure the following which in turn isolates the CDM
nodes as desired.

* There wont be any implicit memory allocation ending up in the CDM node
* Only __GFP_THISNODE marked allocations will come from the CDM node
* CDM node memory can be allocated through mbind(MPOL_BIND) interface
* System RAM memory will be used as fallback option in regular order in
  case the CDM memory is insufficient during targted allocation request

Sample zonelist configuration:

[NODE (0)]						RAM
        ZONELIST_FALLBACK (0xc00000000140da00)
                (0) (node 0) (DMA     0xc00000000140c000)
                (1) (node 1) (DMA     0xc000000100000000)
        ZONELIST_NOFALLBACK (0xc000000001411a10)
                (0) (node 0) (DMA     0xc00000000140c000)
[NODE (1)]						RAM
        ZONELIST_FALLBACK (0xc000000100001a00)
                (0) (node 1) (DMA     0xc000000100000000)
                (1) (node 0) (DMA     0xc00000000140c000)
        ZONELIST_NOFALLBACK (0xc000000100005a10)
                (0) (node 1) (DMA     0xc000000100000000)
[NODE (2)]						CDM
        ZONELIST_FALLBACK (0xc000000001427700)
                (0) (node 2) (Movable 0xc000000001427080)
                (1) (node 0) (DMA     0xc00000000140c000)
                (2) (node 1) (DMA     0xc000000100000000)
        ZONELIST_NOFALLBACK (0xc00000000142b710)
                (0) (node 2) (Movable 0xc000000001427080)
[NODE (3)]						CDM
        ZONELIST_FALLBACK (0xc000000001431400)
                (0) (node 3) (Movable 0xc000000001430d80)
                (1) (node 0) (DMA     0xc00000000140c000)
                (2) (node 1) (DMA     0xc000000100000000)
        ZONELIST_NOFALLBACK (0xc000000001435410)
                (0) (node 3) (Movable 0xc000000001430d80)
[NODE (4)]						CDM
        ZONELIST_FALLBACK (0xc00000000143b100)
                (0) (node 4) (Movable 0xc00000000143aa80)
                (1) (node 0) (DMA     0xc00000000140c000)
                (2) (node 1) (DMA     0xc000000100000000)
        ZONELIST_NOFALLBACK (0xc00000000143f110)
                (0) (node 4) (Movable 0xc00000000143aa80)
Signed-off-by: NAnshuman Khandual <khandual@linux.vnet.ibm.com>
Signed-off-by: Nzhong jiang <zhongjiang@huawei.com>
Signed-off-by: NLijun Fang <fanglijun3@huawei.com>
Reviewed-by: Nzhong jiang <zhongjiang@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

023d1127

mm: Define coherent device memory (CDM) node · 4886e905

由 Anshuman Khandual 提交于 5月 13, 2019

euler inclusion
category: feature
bugzilla: 11082
CVE: NA
-------------------

There are certain devices like specialized accelerator, GPU cards, network
cards, FPGA cards etc which might contain onboard memory which is coherent
along with the existing system RAM while being accessed either from the CPU
or from the device. They share some similar properties with that of normal
system RAM but at the same time can also be different with respect to
system RAM.

User applications might be interested in using this kind of coherent device
memory explicitly or implicitly along side the system RAM utilizing all
possible core memory functions like anon mapping (LRU), file mapping (LRU),
page cache (LRU), driver managed (non LRU), HW poisoning, NUMA migrations
etc. To achieve this kind of tight integration with core memory subsystem,
the device onboard coherent memory must be represented as a memory only
NUMA node. At the same time arch must export some kind of a function to
identify of this node as a coherent device memory not any other regular
cpu less memory only NUMA node.

After achieving the integration with core memory subsystem coherent device
memory might still need some special consideration inside the kernel. There
can be a variety of coherent memory nodes with different expectations from
the core kernel memory. But right now only one kind of special treatment is
considered which requires certain isolation.

Now consider the case of a coherent device memory node type which requires
isolation. This kind of coherent memory is onboard an external device
attached to the system through a link where there is always a chance of a
link failure taking down the entire memory node with it. More over the
memory might also have higher chance of ECC failure as compared to the
system RAM. Hence allocation into this kind of coherent memory node should
be regulated. Kernel allocations must not come here. Normal user space
allocations too should not come here implicitly (without user application
knowing about it). This summarizes isolation requirement of certain kind of
coherent device memory node as an example. There can be different kinds of
isolation requirement also.

Some coherent memory devices might not require isolation altogether after
all. Then there might be other coherent memory devices which might require
some other special treatment after being part of core memory representation
. For now, will look into isolation seeking coherent device memory node not
the other ones.

To implement the integration as well as isolation, the coherent memory node
must be present in N_MEMORY and a new N_COHERENT_DEVICE node mask inside
the node_states[] array. During memory hotplug operations, the new nodemask
N_COHERENT_DEVICE is updated along with N_MEMORY for these coherent device
memory nodes. This also creates the following new sysfs based interface to
list down all the coherent memory nodes of the system.

	/sys/devices/system/node/is_cdm_node

Architectures must export function arch_check_node_cdm() which identifies
any coherent device memory node in case they enable CONFIG_COHERENT_DEVICE.
Signed-off-by: NAnshuman Khandual <khandual@linux.vnet.ibm.com>
Signed-off-by: Nzhong jiang <zhongjiang@huawei.com>
[Backported to 4.19
-remove set or clear node state for memory_hotplug
-separate CONFIG_COHERENT and CPUSET]
Signed-off-by: NLijun Fang <fanglijun3@huawei.com>
Reviewed-by: Nzhong jiang <zhongjiang@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

4886e905

mm/hotplug: treat CMA pages as unmovable · 4700cf13

由 Qian Cai 提交于 4月 29, 2019

mainline inclusion
from mainline-5.1-rc6
commit 1a9f2191
category: bugfix
bugzilla: 14055
CVE: NA

-------------------------------------------------

has_unmovable_pages() is used by allocating CMA and gigantic pages as
well as the memory hotplug.  The later doesn't know how to offline CMA
pool properly now, but if an unused (free) CMA page is encountered, then
has_unmovable_pages() happily considers it as a free memory and
propagates this up the call chain.  Memory offlining code then frees the
page without a proper CMA tear down which leads to an accounting issues.
Moreover if the same memory range is onlined again then the memory never
gets back to the CMA pool.

State after memory offline:

 # grep cma /proc/vmstat
 nr_free_cma 205824

 # cat /sys/kernel/debug/cma/cma-kvm_cma/count
 209920

Also, kmemleak still think those memory address are reserved below but
have already been used by the buddy allocator after onlining.  This
patch fixes the situation by treating CMA pageblocks as unmovable except
when has_unmovable_pages() is called as part of CMA allocation.

  Offlined Pages 4096
  kmemleak: Cannot insert 0xc000201f7d040008 into the object search tree (overlaps existing)
  Call Trace:
    dump_stack+0xb0/0xf4 (unreliable)
    create_object+0x344/0x380
    __kmalloc_node+0x3ec/0x860
    kvmalloc_node+0x58/0x110
    seq_read+0x41c/0x620
    __vfs_read+0x3c/0x70
    vfs_read+0xbc/0x1a0
    ksys_read+0x7c/0x140
    system_call+0x5c/0x70
  kmemleak: Kernel memory leak detector disabled
  kmemleak: Object 0xc000201cc8000000 (size 13757317120):
  kmemleak:   comm "swapper/0", pid 0, jiffies 4294937297
  kmemleak:   min_count = -1
  kmemleak:   count = 0
  kmemleak:   flags = 0x5
  kmemleak:   checksum = 0
  kmemleak:   backtrace:
       cma_declare_contiguous+0x2a4/0x3b0
       kvm_cma_reserve+0x11c/0x134
       setup_arch+0x300/0x3f8
       start_kernel+0x9c/0x6e8
       start_here_common+0x1c/0x4b0
  kmemleak: Automatic memory scanning thread ended

[cai@lca.pw: use is_migrate_cma_page() and update commit log]
  Link: http://lkml.kernel.org/r/20190416170510.20048-1-cai@lca.pw
Link: http://lkml.kernel.org/r/20190413002623.8967-1-cai@lca.pwSigned-off-by: NQian Cai <cai@lca.pw>
Acked-by: NMichal Hocko <mhocko@suse.com>
Acked-by: NVlastimil Babka <vbabka@suse.cz>
Reviewed-by: NOscar Salvador <osalvador@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Nzhong jiang <zhongjiang@huawei.com>
Reviewed-by: NJing Xiangfeng <jingxiangfeng@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

4700cf13

mm/hotplug: fix offline undo_isolate_page_range() · 47669159

由 Qian Cai 提交于 4月 08, 2019

mainline inclusion
from mainline-5.1-rc3
commit 9b7ea46a82b31c74a37e6ff1c2a1df7d53e392ab
category: bugfix
bugzilla: 13472
CVE: NA

-------------------------------------------------

Commit f1dd2cd1 ("mm, memory_hotplug: do not associate hotadded
memory to zones until online") introduced move_pfn_range_to_zone() which
calls memmap_init_zone() during onlining a memory block.
memmap_init_zone() will reset pagetype flags and makes migrate type to
be MOVABLE.

However, in __offline_pages(), it also call undo_isolate_page_range()
after offline_isolated_pages() to do the same thing.  Due to commit
2ce13640 ("mm: __first_valid_page skip over offline pages") changed
__first_valid_page() to skip offline pages, undo_isolate_page_range()
here just waste CPU cycles looping around the offlining PFN range while
doing nothing, because __first_valid_page() will return NULL as
offline_isolated_pages() has already marked all memory sections within
the pfn range as offline via offline_mem_sections().

Also, after calling the "useless" undo_isolate_page_range() here, it
reaches the point of no returning by notifying MEM_OFFLINE.  Those pages
will be marked as MIGRATE_MOVABLE again once onlining.  The only thing
left to do is to decrease the number of isolated pageblocks zone counter
which would make some paths of the page allocation slower that the above
commit introduced.

Even if alloc_contig_range() can be used to isolate 16GB-hugetlb pages
on ppc64, an "int" should still be enough to represent the number of
pageblocks there.  Fix an incorrect comment along the way.

[cai@lca.pw: v4]
  Link: http://lkml.kernel.org/r/20190314150641.59358-1-cai@lca.pw
Link: http://lkml.kernel.org/r/20190313143133.46200-1-cai@lca.pw
Fixes: 2ce13640 ("mm: __first_valid_page skip over offline pages")
Signed-off-by: NQian Cai <cai@lca.pw>
Acked-by: NMichal Hocko <mhocko@suse.com>
Reviewed-by: NOscar Salvador <osalvador@suse.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org>	[4.13+]
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Nzhong jiang <zhongjiang@huawei.com>
Reviewed-by: NJing Xiangfeng <jingxiangfeng@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

47669159

mm: only report isolation failures when offlining memory · 2a5141d5

由 Michal Hocko 提交于 4月 08, 2019

mainline inclusion
from mainline-v5.0-rc1
commit d381c54760dcfad23743da40516e7e003d73952a
category: bugfix
bugzilla: 13472
CVE: NA

------------------------------------------------

Heiko has complained that his log is swamped by warnings from
has_unmovable_pages

[   20.536664] page dumped because: has_unmovable_pages
[   20.536792] page:000003d081ff4080 count:1 mapcount:0 mapping:000000008ff88600 index:0x0 compound_mapcount: 0
[   20.536794] flags: 0x3fffe0000010200(slab|head)
[   20.536795] raw: 03fffe0000010200 0000000000000100 0000000000000200 000000008ff88600
[   20.536796] raw: 0000000000000000 0020004100000000 ffffffff00000001 0000000000000000
[   20.536797] page dumped because: has_unmovable_pages
[   20.536814] page:000003d0823b0000 count:1 mapcount:0 mapping:0000000000000000 index:0x0
[   20.536815] flags: 0x7fffe0000000000()
[   20.536817] raw: 07fffe0000000000 0000000000000100 0000000000000200 0000000000000000
[   20.536818] raw: 0000000000000000 0000000000000000 ffffffff00000001 0000000000000000

which are not triggered by the memory hotplug but rather CMA allocator.
The original idea behind dumping the page state for all call paths was
that these messages will be helpful debugging failures.  From the above it
seems that this is not the case for the CMA path because we are lacking
much more context.  E.g the second reported page might be a CMA allocated
page.  It is still interesting to see a slab page in the CMA area but it
is hard to tell whether this is bug from the above output alone.

Address this issue by dumping the page state only on request.  Both
start_isolate_page_range and has_unmovable_pages already have an argument
to ignore hwpoison pages so make this argument more generic and turn it
into flags and allow callers to combine non-default modes into a mask.
While we are at it, has_unmovable_pages call from
is_pageblock_removable_nolock (sysfs removable file) is questionable to
report the failure so drop it from there as well.

Link: http://lkml.kernel.org/r/20181218092802.31429-1-mhocko@kernel.orgSigned-off-by: NMichal Hocko <mhocko@suse.com>
Reported-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Reviewed-by: NOscar Salvador <osalvador@suse.de>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Nzhong jiang <zhongjiang@huawei.com>
Reviewed-by: NJing Xiangfeng <jingxiangfeng@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

2a5141d5

mm, memory_hotplug: be more verbose for memory offline failures · 4a5f2575

由 Michal Hocko 提交于 4月 08, 2019

mainline inclusion
from mainline-5.0-rc1
commit 2932c8b0
category: bugfix
bugzilla: 13472
CVE: NA

------------------------------------------------

There is only very limited information printed when the memory offlining
fails:

[ 1984.506184] rac1 kernel: memory offlining [mem 0x82600000000-0x8267fffffff] failed due to signal backoff

This tells us that the failure is triggered by the userspace intervention
but it doesn't tell us much more about the underlying reason.  It might be
that the page migration failes repeatedly and the userspace timeout
expires and send a signal or it might be some of the earlier steps
(isolation, memory notifier) takes too long.

If the migration failes then it would be really helpful to see which page
that and its state.  The same applies to the isolation phase.  If we fail
to isolate a page from the allocator then knowing the state of the page
would be helpful as well.

Dump the page state that fails to get isolated or migrated.  This will
tell us more about the failure and what to focus on during debugging.

[akpm@linux-foundation.org: add missing printk arg]
[mhocko@suse.com: tweak dump_page() `reason' text]
  Link: http://lkml.kernel.org/r/20181116083020.20260-6-mhocko@kernel.org
Link: http://lkml.kernel.org/r/20181107101830.17405-6-mhocko@kernel.orgSigned-off-by: NMichal Hocko <mhocko@suse.com>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Reviewed-by: NOscar Salvador <osalvador@suse.de>
Reviewed-by: NAnshuman Khandual <anshuman.khandual@arm.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Oscar Salvador <OSalvador@suse.com>
Cc: William Kucharski <william.kucharski@oracle.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Nzhong jiang <zhongjiang@huawei.com>
Reviewed-by: NJing Xiangfeng <jingxiangfeng@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

4a5f2575

mm: page_alloc: fix ref bias in page_frag_alloc() for 1-byte allocs · 92834760

由 Jann Horn 提交于 2月 13, 2019

[ Upstream commit 2c2ade81 ]

The basic idea behind ->pagecnt_bias is: If we pre-allocate the maximum
number of references that we might need to create in the fastpath later,
the bump-allocation fastpath only has to modify the non-atomic bias value
that tracks the number of extra references we hold instead of the atomic
refcount. The maximum number of allocations we can serve (under the
assumption that no allocation is made with size 0) is nc->size, so that's
the bias used.

However, even when all memory in the allocation has been given away, a
reference to the page is still held; and in the `offset < 0` slowpath, the
page may be reused if everyone else has dropped their references.
This means that the necessary number of references is actually
`nc->size+1`.

Luckily, from a quick grep, it looks like the only path that can call
page_frag_alloc(fragsz=1) is TAP with the IFF_NAPI_FRAGS flag, which
requires CAP_NET_ADMIN in the init namespace and is only intended to be
used for kernel testing and fuzzing.

To test for this issue, put a `WARN_ON(page_ref_count(page) == 0)` in the
`offset < 0` path, below the virt_to_page() call, and then repeatedly call
writev() on a TAP device with IFF_TAP|IFF_NO_PI|IFF_NAPI_FRAGS|IFF_NAPI,
with a vector consisting of 15 elements containing 1 byte each.
Signed-off-by: NJann Horn <jannh@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

92834760

page_poison: play nicely with KASAN · 15129a33

由 Qian Cai 提交于 3月 15, 2019

mainline inclusion
from mainline-5.0
commit 4117992df66a
category: bugfix
bugzilla: 11620
CVE: NA

------------------------------------------------

KASAN does not play well with the page poisoning (CONFIG_PAGE_POISONING).
It triggers false positives in the allocation path,

BUG: KASAN: use-after-free in memchr_inv+0x2ea/0x330
Read of size 8 at addr ffff88881f800000 by task swapper/0
CPU: 0 PID: 0 Comm: swapper Not tainted 5.0.0-rc1+ #54
Call Trace:
 dump_stack+0xe0/0x19a
 print_address_description.cold.2+0x9/0x28b
 kasan_report.cold.3+0x7a/0xb5
 __asan_report_load8_noabort+0x19/0x20
 memchr_inv+0x2ea/0x330
 kernel_poison_pages+0x103/0x3d5
 get_page_from_freelist+0x15e7/0x4d90

because KASAN has not yet unpoisoned the shadow page for allocation before
it checks memchr_inv() but only found a stale poison pattern.

Also, false positives in free path,

BUG: KASAN: slab-out-of-bounds in kernel_poison_pages+0x29e/0x3d5
Write of size 4096 at addr ffff8888112cc000 by task swapper/0/1
CPU: 5 PID: 1 Comm: swapper/0 Not tainted 5.0.0-rc1+ #55
Call Trace:
 dump_stack+0xe0/0x19a
 print_address_description.cold.2+0x9/0x28b
 kasan_report.cold.3+0x7a/0xb5
 check_memory_region+0x22d/0x250
 memset+0x28/0x40
 kernel_poison_pages+0x29e/0x3d5
 __free_pages_ok+0x75f/0x13e0

due to KASAN adds poisoned redzones around slab objects, but the page
poisoning needs to poison the whole page.

Link: http://lkml.kernel.org/r/20190114233405.67843-1-cai@lca.pwSigned-off-by: NQian Cai <cai@lca.pw>
Acked-by: NAndrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Nzhong jiang <zhongjiang@huawei.com>
Reviewed-by: NJing Xiangfeng <jingxiangfeng@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

15129a33

pagecache: add Kconfig to enable/disable the feature · 862e2308

由 zhongjiang 提交于 2月 21, 2019

euler inclusion
category: bugfix
CVE: NA
Bugzilla: 9580

---------------------------

Just add Kconfig to the feature.
Signed-off-by: Nzhongjiang <zhongjiang@huawei.com>
Reviewed-by: NJing Xiangfeng <jingxiangfeng@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

862e2308

pagecache: add sysctl interface to limit pagecache · 6174ecb5

由 zhong jiang 提交于 2月 15, 2019

euleros inclusion
category: feature
feature: pagecache limit

add proc sysctl interface to set pagecache limit for reclaim memory
Signed-off-by: Nzhong jiang <zhongjiang@huawei.com>
Reviewed-by: NJing xiangfeng <jingxiangfeng@huawei.com>
Signed-off-by: Nzhong jiang <zhongjiang@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

6174ecb5

mm/page_alloc.c: don't call kasan_free_pages() at deferred mem init · d453a476

由 Waiman Long 提交于 12月 28, 2018

[ Upstream commit 3c0c12cc8f00ca5f81acb010023b8eb13e9a7004 ]

When CONFIG_KASAN is enabled on large memory SMP systems, the deferrred
pages initialization can take a long time.  Below were the reported init
times on a 8-socket 96-core 4TB IvyBridge system.

  1) Non-debug kernel without CONFIG_KASAN
     [    8.764222] node 1 initialised, 132086516 pages in 7027ms

  2) Debug kernel with CONFIG_KASAN
     [  146.288115] node 1 initialised, 132075466 pages in 143052ms

So the page init time in a debug kernel was 20X of the non-debug kernel.
The long init time can be problematic as the page initialization is done
with interrupt disabled.  In this particular case, it caused the
appearance of following warning messages as well as NMI backtraces of all
the cores that were doing the initialization.

[   68.240049] rcu: INFO: rcu_sched detected stalls on CPUs/tasks:
[   68.241000] rcu: 	25-...0: (100 ticks this GP) idle=b72/1/0x4000000000000000 softirq=915/915 fqs=16252
[   68.241000] rcu: 	44-...0: (95 ticks this GP) idle=49a/1/0x4000000000000000 softirq=788/788 fqs=16253
[   68.241000] rcu: 	54-...0: (104 ticks this GP) idle=03a/1/0x4000000000000000 softirq=721/825 fqs=16253
[   68.241000] rcu: 	60-...0: (103 ticks this GP) idle=cbe/1/0x4000000000000000 softirq=637/740 fqs=16253
[   68.241000] rcu: 	72-...0: (105 ticks this GP) idle=786/1/0x4000000000000000 softirq=536/641 fqs=16253
[   68.241000] rcu: 	84-...0: (99 ticks this GP) idle=292/1/0x4000000000000000 softirq=537/537 fqs=16253
[   68.241000] rcu: 	111-...0: (104 ticks this GP) idle=bde/1/0x4000000000000000 softirq=474/476 fqs=16253
[   68.241000] rcu: 	(detected by 13, t=65018 jiffies, g=249, q=2)

The long init time was mainly caused by the call to kasan_free_pages() to
poison the newly initialized pages.  On a 4TB system, we are talking about
almost 500GB of memory probably on the same node.

In reality, we may not need to poison the newly initialized pages before
they are ever allocated.  So KASAN poisoning of freed pages before the
completion of deferred memory initialization is now disabled.  Those pages
will be properly poisoned when they are allocated or freed after deferred
pages initialization is done.

With this change, the new page initialization time became:

[   21.948010] node 1 initialised, 132075466 pages in 18702ms

This was still about double the non-debug kernel time, but was much
better than before.

Link: http://lkml.kernel.org/r/1544459388-8736-1-git-send-email-longman@redhat.comSigned-off-by: NWaiman Long <longman@redhat.com>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Pasha Tatashin <Pavel.Tatashin@microsoft.com>
Cc: Oscar Salvador <osalvador@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

d453a476

Revert "mm, memory_hotplug: initialize struct pages for the full memory section" · 79d3b9b9

由 Michal Hocko 提交于 1月 25, 2019

commit 4aa9fc2a435abe95a1e8d7f8c7b3d6356514b37a upstream.

This reverts commit 2830bf6f05fb3e05bc4743274b806c821807a684.

The underlying assumption that one sparse section belongs into a single
numa node doesn't hold really. Robert Shteynfeld has reported a boot
failure. The boot log was not captured but his memory layout is as
follows:

  Early memory node ranges
    node   1: [mem 0x0000000000001000-0x0000000000090fff]
    node   1: [mem 0x0000000000100000-0x00000000dbdf8fff]
    node   1: [mem 0x0000000100000000-0x0000001423ffffff]
    node   0: [mem 0x0000001424000000-0x0000002023ffffff]

This means that node0 starts in the middle of a memory section which is
also in node1.  memmap_init_zone tries to initialize padding of a
section even when it is outside of the given pfn range because there are
code paths (e.g.  memory hotplug) which assume that the full worth of
memory section is always initialized.

In this particular case, though, such a range is already intialized and
most likely already managed by the page allocator.  Scribbling over
those pages corrupts the internal state and likely blows up when any of
those pages gets used.
Reported-by: NRobert Shteynfeld <robert.shteynfeld@gmail.com>
Fixes: 2830bf6f05fb ("mm, memory_hotplug: initialize struct pages for the full memory section")
Cc: stable@kernel.org
Signed-off-by: NMichal Hocko <mhocko@suse.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

79d3b9b9

29 12月, 2018 2 次提交

mm, page_alloc: fix has_unmovable_pages for HugePages · e27666dd

由 Oscar Salvador 提交于 12月 21, 2018

commit 17e2e7d7e1b83fa324b3f099bfe426659aa3c2a4 upstream.

While playing with gigantic hugepages and memory_hotplug, I triggered
the following #PF when "cat memoryX/removable":

  BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
  #PF error: [normal kernel read fault]
  PGD 0 P4D 0
  Oops: 0000 [#1] SMP PTI
  CPU: 1 PID: 1481 Comm: cat Tainted: G            E     4.20.0-rc6-mm1-1-default+ #18
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.0.0-prebuilt.qemu-project.org 04/01/2014
  RIP: 0010:has_unmovable_pages+0x154/0x210
  Call Trace:
   is_mem_section_removable+0x7d/0x100
   removable_show+0x90/0xb0
   dev_attr_show+0x1c/0x50
   sysfs_kf_seq_show+0xca/0x1b0
   seq_read+0x133/0x380
   __vfs_read+0x26/0x180
   vfs_read+0x89/0x140
   ksys_read+0x42/0x90
   do_syscall_64+0x5b/0x180
   entry_SYSCALL_64_after_hwframe+0x44/0xa9

The reason is we do not pass the Head to page_hstate(), and so, the call
to compound_order() in page_hstate() returns 0, so we end up checking
all hstates's size to match PAGE_SIZE.

Obviously, we do not find any hstate matching that size, and we return
NULL.  Then, we dereference that NULL pointer in
hugepage_migration_supported() and we got the #PF from above.

Fix that by getting the head page before calling page_hstate().

Also, since gigantic pages span several pageblocks, re-adjust the logic
for skipping pages.  While are it, we can also get rid of the
round_up().

[osalvador@suse.de: remove round_up(), adjust skip pages logic per Michal]
  Link: http://lkml.kernel.org/r/20181221062809.31771-1-osalvador@suse.de
Link: http://lkml.kernel.org/r/20181217225113.17864-1-osalvador@suse.deSigned-off-by: NOscar Salvador <osalvador@suse.de>
Acked-by: NMichal Hocko <mhocko@suse.com>
Reviewed-by: NDavid Hildenbrand <david@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Pavel Tatashin <pavel.tatashin@microsoft.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

e27666dd

mm, memory_hotplug: initialize struct pages for the full memory section · 7592dbfa

由 Mikhail Zaslonko 提交于 12月 21, 2018

commit 2830bf6f05fb3e05bc4743274b806c821807a684 upstream.

If memory end is not aligned with the sparse memory section boundary,
the mapping of such a section is only partly initialized.  This may lead
to VM_BUG_ON due to uninitialized struct page access from
is_mem_section_removable() or test_pages_in_a_zone() function triggered
by memory_hotplug sysfs handlers:

Here are the the panic examples:
 CONFIG_DEBUG_VM=y
 CONFIG_DEBUG_VM_PGFLAGS=y

 kernel parameter mem=2050M
 --------------------------
 page:000003d082008000 is uninitialized and poisoned
 page dumped because: VM_BUG_ON_PAGE(PagePoisoned(p))
 Call Trace:
 ( test_pages_in_a_zone+0xde/0x160)
   show_valid_zones+0x5c/0x190
   dev_attr_show+0x34/0x70
   sysfs_kf_seq_show+0xc8/0x148
   seq_read+0x204/0x480
   __vfs_read+0x32/0x178
   vfs_read+0x82/0x138
   ksys_read+0x5a/0xb0
   system_call+0xdc/0x2d8
 Last Breaking-Event-Address:
   test_pages_in_a_zone+0xde/0x160
 Kernel panic - not syncing: Fatal exception: panic_on_oops

 kernel parameter mem=3075M
 --------------------------
 page:000003d08300c000 is uninitialized and poisoned
 page dumped because: VM_BUG_ON_PAGE(PagePoisoned(p))
 Call Trace:
 ( is_mem_section_removable+0xb4/0x190)
   show_mem_removable+0x9a/0xd8
   dev_attr_show+0x34/0x70
   sysfs_kf_seq_show+0xc8/0x148
   seq_read+0x204/0x480
   __vfs_read+0x32/0x178
   vfs_read+0x82/0x138
   ksys_read+0x5a/0xb0
   system_call+0xdc/0x2d8
 Last Breaking-Event-Address:
   is_mem_section_removable+0xb4/0x190
 Kernel panic - not syncing: Fatal exception: panic_on_oops

Fix the problem by initializing the last memory section of each zone in
memmap_init_zone() till the very end, even if it goes beyond the zone end.

Michal said:

: This has alwways been problem AFAIU.  It just went unnoticed because we
: have zeroed memmaps during allocation before f7f99100 ("mm: stop
: zeroing memory during allocation in vmemmap") and so the above test
: would simply skip these ranges as belonging to zone 0 or provided a
: garbage.
:
: So I guess we do care for post f7f99100 kernels mostly and
: therefore Fixes: f7f99100 ("mm: stop zeroing memory during
: allocation in vmemmap")

Link: http://lkml.kernel.org/r/20181212172712.34019-2-zaslonko@linux.ibm.com
Fixes: f7f99100 ("mm: stop zeroing memory during allocation in vmemmap")
Signed-off-by: NMikhail Zaslonko <zaslonko@linux.ibm.com>
Reviewed-by: NGerald Schaefer <gerald.schaefer@de.ibm.com>
Suggested-by: NMichal Hocko <mhocko@kernel.org>
Acked-by: NMichal Hocko <mhocko@suse.com>
Reported-by: NMikhail Gavrilov <mikhail.v.gavrilov@gmail.com>
Tested-by: NMikhail Gavrilov <mikhail.v.gavrilov@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Cc: Pasha Tatashin <Pavel.Tatashin@microsoft.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

7592dbfa

17 12月, 2018 1 次提交

mm/page_alloc.c: fix calculation of pgdat->nr_zones · 505bc9f3

由 Wei Yang 提交于 11月 30, 2018

[ Upstream commit 8f416836c0d50b198cad1225132e5abebf8980dc ]

init_currently_empty_zone() will adjust pgdat->nr_zones and set it to
'zone_idx(zone) + 1' unconditionally.  This is correct in the normal
case, while not exact in hot-plug situation.

This function is used in two places:

  * free_area_init_core()
  * move_pfn_range_to_zone()

In the first case, we are sure zone index increase monotonically.  While
in the second one, this is under users control.

One way to reproduce this is:
----------------------------

1. create a virtual machine with empty node1

   -m 4G,slots=32,maxmem=32G \
   -smp 4,maxcpus=8          \
   -numa node,nodeid=0,mem=4G,cpus=0-3 \
   -numa node,nodeid=1,mem=0G,cpus=4-7

2. hot-add cpu 3-7

   cpu-add [3-7]

2. hot-add memory to nod1

   object_add memory-backend-ram,id=ram0,size=1G
   device_add pc-dimm,id=dimm0,memdev=ram0,node=1

3. online memory with following order

   echo online_movable > memory47/state
   echo online > memory40/state

After this, node1 will have its nr_zones equals to (ZONE_NORMAL + 1)
instead of (ZONE_MOVABLE + 1).

Michal said:
 "Having an incorrect nr_zones might result in all sorts of problems
  which would be quite hard to debug (e.g. reclaim not considering the
  movable zone). I do not expect many users would suffer from this it
  but still this is trivial and obviously right thing to do so
  backporting to the stable tree shouldn't be harmful (last famous
  words)"

Link: http://lkml.kernel.org/r/20181117022022.9956-1-richard.weiyang@gmail.com
Fixes: f1dd2cd1 ("mm, memory_hotplug: do not associate hotadded memory to zones until online")
Signed-off-by: NWei Yang <richard.weiyang@gmail.com>
Acked-by: NMichal Hocko <mhocko@suse.com>
Reviewed-by: NOscar Salvador <osalvador@suse.de>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NSasha Levin <sashal@kernel.org>

505bc9f3

01 12月, 2018 2 次提交

mm, page_alloc: check for max order in hot path · 9dec3855

由 Michal Hocko 提交于 11月 16, 2018

[ Upstream commit c63ae43ba53bc432b414fd73dd5f4b01fcb1ab43 ]

Konstantin has noticed that kvmalloc might trigger the following
warning:

  WARNING: CPU: 0 PID: 6676 at mm/vmstat.c:986 __fragmentation_index+0x54/0x60
  [...]
  Call Trace:
   fragmentation_index+0x76/0x90
   compaction_suitable+0x4f/0xf0
   shrink_node+0x295/0x310
   node_reclaim+0x205/0x250
   get_page_from_freelist+0x649/0xad0
   __alloc_pages_nodemask+0x12a/0x2a0
   kmalloc_large_node+0x47/0x90
   __kmalloc_node+0x22b/0x2e0
   kvmalloc_node+0x3e/0x70
   xt_alloc_table_info+0x3a/0x80 [x_tables]
   do_ip6t_set_ctl+0xcd/0x1c0 [ip6_tables]
   nf_setsockopt+0x44/0x60
   SyS_setsockopt+0x6f/0xc0
   do_syscall_64+0x67/0x120
   entry_SYSCALL_64_after_hwframe+0x3d/0xa2

the problem is that we only check for an out of bound order in the slow
path and the node reclaim might happen from the fast path already.  This
is fixable by making sure that kvmalloc doesn't ever use kmalloc for
requests that are larger than KMALLOC_MAX_SIZE but this also shows that
the code is rather fragile.  A recent UBSAN report just underlines that
by the following report

  UBSAN: Undefined behaviour in mm/page_alloc.c:3117:19
  shift exponent 51 is too large for 32-bit type 'int'
  CPU: 0 PID: 6520 Comm: syz-executor1 Not tainted 4.19.0-rc2 #1
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
  Call Trace:
   __dump_stack lib/dump_stack.c:77 [inline]
   dump_stack+0xd2/0x148 lib/dump_stack.c:113
   ubsan_epilogue+0x12/0x94 lib/ubsan.c:159
   __ubsan_handle_shift_out_of_bounds+0x2b6/0x30b lib/ubsan.c:425
   __zone_watermark_ok+0x2c7/0x400 mm/page_alloc.c:3117
   zone_watermark_fast mm/page_alloc.c:3216 [inline]
   get_page_from_freelist+0xc49/0x44c0 mm/page_alloc.c:3300
   __alloc_pages_nodemask+0x21e/0x640 mm/page_alloc.c:4370
   alloc_pages_current+0xcc/0x210 mm/mempolicy.c:2093
   alloc_pages include/linux/gfp.h:509 [inline]
   __get_free_pages+0x12/0x60 mm/page_alloc.c:4414
   dma_mem_alloc+0x36/0x50 arch/x86/include/asm/floppy.h:156
   raw_cmd_copyin drivers/block/floppy.c:3159 [inline]
   raw_cmd_ioctl drivers/block/floppy.c:3206 [inline]
   fd_locked_ioctl+0xa00/0x2c10 drivers/block/floppy.c:3544
   fd_ioctl+0x40/0x60 drivers/block/floppy.c:3571
   __blkdev_driver_ioctl block/ioctl.c:303 [inline]
   blkdev_ioctl+0xb3c/0x1a30 block/ioctl.c:601
   block_ioctl+0x105/0x150 fs/block_dev.c:1883
   vfs_ioctl fs/ioctl.c:46 [inline]
   do_vfs_ioctl+0x1c0/0x1150 fs/ioctl.c:687
   ksys_ioctl+0x9e/0xb0 fs/ioctl.c:702
   __do_sys_ioctl fs/ioctl.c:709 [inline]
   __se_sys_ioctl fs/ioctl.c:707 [inline]
   __x64_sys_ioctl+0x7e/0xc0 fs/ioctl.c:707
   do_syscall_64+0xc4/0x510 arch/x86/entry/common.c:290
   entry_SYSCALL_64_after_hwframe+0x49/0xbe

Note that this is not a kvmalloc path.  It is just that the fast path
really depends on having sanitzed order as well.  Therefore move the
order check to the fast path.

Link: http://lkml.kernel.org/r/20181113094305.GM15120@dhcp22.suse.czSigned-off-by: NMichal Hocko <mhocko@suse.com>
Reported-by: NKonstantin Khlebnikov <khlebnikov@yandex-team.ru>
Reported-by: NKyungtae Kim <kt0755@gmail.com>
Acked-by: NVlastimil Babka <vbabka@suse.cz>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Pavel Tatashin <pavel.tatashin@microsoft.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Aaron Lu <aaron.lu@intel.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Byoungyoung Lee <lifeasageek@gmail.com>
Cc: "Dae R. Jeong" <threeearcat@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NSasha Levin <sashal@kernel.org>

9dec3855

mm, memory_hotplug: check zone_movable in has_unmovable_pages · b44fd126

由 Michal Hocko 提交于 11月 16, 2018

[ Upstream commit 9d7899999c62c1a81129b76d2a6ecbc4655e1597 ]

Page state checks are racy.  Under a heavy memory workload (e.g.  stress
-m 200 -t 2h) it is quite easy to hit a race window when the page is
allocated but its state is not fully populated yet.  A debugging patch to
dump the struct page state shows

  has_unmovable_pages: pfn:0x10dfec00, found:0x1, count:0x0
  page:ffffea0437fb0000 count:1 mapcount:1 mapping:ffff880e05239841 index:0x7f26e5000 compound_mapcount: 1
  flags: 0x5fffffc0090034(uptodate|lru|active|head|swapbacked)

Note that the state has been checked for both PageLRU and PageSwapBacked
already.  Closing this race completely would require some sort of retry
logic.  This can be tricky and error prone (think of potential endless
or long taking loops).

Workaround this problem for movable zones at least.  Such a zone should
only contain movable pages.  Commit 15c30bc0 ("mm, memory_hotplug:
make has_unmovable_pages more robust") has told us that this is not
strictly true though.  Bootmem pages should be marked reserved though so
we can move the original check after the PageReserved check.  Pages from
other zones are still prone to races but we even do not pretend that
memory hotremove works for those so pre-mature failure doesn't hurt that
much.

Link: http://lkml.kernel.org/r/20181106095524.14629-1-mhocko@kernel.org
Fixes: 15c30bc0 ("mm, memory_hotplug: make has_unmovable_pages more robust")
Signed-off-by: NMichal Hocko <mhocko@suse.com>
Reported-by: NBaoquan He <bhe@redhat.com>
Tested-by: NBaoquan He <bhe@redhat.com>
Acked-by: NBaoquan He <bhe@redhat.com>
Reviewed-by: NOscar Salvador <osalvador@suse.de>
Acked-by: NBalbir Singh <bsingharora@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NSasha Levin <sashal@kernel.org>

b44fd126

09 10月, 2018 1 次提交

mm, sched/numa: Remove remaining traces of NUMA rate-limiting · e0546375

由 Srikar Dronamraju 提交于 10月 06, 2018

Remove the leftover pglist_data::numabalancing_migrate_lock and its
initialization, we stopped using this lock with:

  efaffc5e ("mm, sched/numa: Remove rate-limiting of automatic NUMA balancing migration")

[ mingo: Rewrote the changelog. ]
Signed-off-by: NSrikar Dronamraju <srikar@linux.vnet.ibm.com>
Acked-by: NMel Gorman <mgorman@techsingularity.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Linux-MM <linux-mm@kvack.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1538824999-31230-1-git-send-email-srikar@linux.vnet.ibm.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

e0546375

02 10月, 2018 1 次提交

mm, sched/numa: Remove rate-limiting of automatic NUMA balancing migration · efaffc5e

由 Mel Gorman 提交于 10月 01, 2018

Rate limiting of page migrations due to automatic NUMA balancing was
introduced to mitigate the worst-case scenario of migrating at high
frequency due to false sharing or slowly ping-ponging between nodes.
Since then, a lot of effort was spent on correctly identifying these
pages and avoiding unnecessary migrations and the safety net may no longer
be required.

Jirka Hladky reported a regression in 4.17 due to a scheduler patch that
avoids spreading STREAM tasks wide prematurely. However, once the task
was properly placed, it delayed migrating the memory due to rate limiting.
Increasing the limit fixed the problem for him.

Currently, the limit is hard-coded and does not account for the real
capabilities of the hardware. Even if an estimate was attempted, it would
not properly account for the number of memory controllers and it could
not account for the amount of bandwidth used for normal accesses. Rather
than fudging, this patch simply eliminates the rate limiting.

However, Jirka reports that a STREAM configuration using multiple
processes achieved similar performance to 4.16. In local tests, this patch
improved performance of STREAM relative to the baseline but it is somewhat
machine-dependent. Most workloads show little or not performance difference
implying that there is not a heavily reliance on the throttling mechanism
and it is safe to remove.

STREAM on 2-socket machine
                         4.19.0-rc5             4.19.0-rc5
                         numab-v1r1       noratelimit-v1r1
MB/sec copy     43298.52 (   0.00%)    44673.38 (   3.18%)
MB/sec scale    30115.06 (   0.00%)    31293.06 (   3.91%)
MB/sec add      32825.12 (   0.00%)    34883.62 (   6.27%)
MB/sec triad    32549.52 (   0.00%)    34906.60 (   7.24%
Signed-off-by: NMel Gorman <mgorman@techsingularity.net>
Reviewed-by: NRik van Riel <riel@surriel.com>
Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Jirka Hladky <jhladky@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Linux-MM <linux-mm@kvack.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20181001100525.29789-2-mgorman@techsingularity.netSigned-off-by: NIngo Molnar <mingo@kernel.org>

efaffc5e

05 9月, 2018 1 次提交

mm/hugetlb: filter out hugetlb pages if HUGEPAGE migration is not supported. · 464c7ffb

由 Aneesh Kumar K.V 提交于 9月 04, 2018

When scanning for movable pages, filter out Hugetlb pages if hugepage
migration is not supported.  Without this we hit infinte loop in
__offline_pages() where we do

	pfn = scan_movable_pages(start_pfn, end_pfn);
	if (pfn) { /* We have movable pages */
		ret = do_migrate_range(pfn, end_pfn);
		goto repeat;
	}

Fix this by checking hugepage_migration_supported both in
has_unmovable_pages which is the primary backoff mechanism for page
offlining and for consistency reasons also into scan_movable_pages
because it doesn't make any sense to return a pfn to non-migrateable
huge page.

This issue was revealed by, but not caused by 72b39cfc ("mm,
memory_hotplug: do not fail offlining too early").

Link: http://lkml.kernel.org/r/20180824063314.21981-1-aneesh.kumar@linux.ibm.com
Fixes: 72b39cfc ("mm, memory_hotplug: do not fail offlining too early")
Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Reported-by: NHaren Myneni <haren@linux.vnet.ibm.com>
Acked-by: NMichal Hocko <mhocko@suse.com>
Reviewed-by: NNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

464c7ffb

30 8月, 2018 1 次提交

notifier: Remove notifier header file wherever not used · 13ba17be

由 Mukesh Ojha 提交于 8月 24, 2018

The conversion of the hotplug notifiers to a state machine left the
notifier.h includes around in some places. Remove them.
Signed-off-by: NMukesh Ojha <mojha@codeaurora.org>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/1535114033-4605-1-git-send-email-mojha@codeaurora.org

13ba17be

24 8月, 2018 1 次提交

mm: soft-offline: close the race against page allocation · d4ae9916

由 Naoya Horiguchi 提交于 8月 23, 2018

A process can be killed with SIGBUS(BUS_MCEERR_AR) when it tries to
allocate a page that was just freed on the way of soft-offline.  This is
undesirable because soft-offline (which is about corrected error) is
less aggressive than hard-offline (which is about uncorrected error),
and we can make soft-offline fail and keep using the page for good
reason like "system is busy."

Two main changes of this patch are:

- setting migrate type of the target page to MIGRATE_ISOLATE. As done
  in free_unref_page_commit(), this makes kernel bypass pcplist when
  freeing the page. So we can assume that the page is in freelist just
  after put_page() returns,

- setting PG_hwpoison on free page under zone->lock which protects
  freelists, so this allows us to avoid setting PG_hwpoison on a page
  that is decided to be allocated soon.

[akpm@linux-foundation.org: tweak set_hwpoison_free_buddy_page() comment]
Link: http://lkml.kernel.org/r/1531452366-11661-3-git-send-email-n-horiguchi@ah.jp.nec.comSigned-off-by: NNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Reported-by: NXishi Qiu <xishi.qiuxishi@alibaba-inc.com>
Tested-by: NMike Kravetz <mike.kravetz@oracle.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: <zy.zhengyi@alibaba-inc.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

d4ae9916

23 8月, 2018 5 次提交

mm/page_alloc: Introduce free_area_init_core_hotplug · 03e85f9d

由 Oscar Salvador 提交于 8月 21, 2018

Currently, whenever a new node is created/re-used from the memhotplug
path, we call free_area_init_node()->free_area_init_core().  But there is
some code that we do not really need to run when we are coming from such
path.

free_area_init_core() performs the following actions:

1) Initializes pgdat internals, such as spinlock, waitqueues and more.
2) Account # nr_all_pages and # nr_kernel_pages. These values are used later on
   when creating hash tables.
3) Account number of managed_pages per zone, substracting dma_reserved and
   memmap pages.
4) Initializes some fields of the zone structure data
5) Calls init_currently_empty_zone to initialize all the freelists
6) Calls memmap_init to initialize all pages belonging to certain zone

When called from memhotplug path, free_area_init_core() only performs
actions #1 and #4.

Action #2 is pointless as the zones do not have any pages since either the
node was freed, or we are re-using it, eitherway all zones belonging to
this node should have 0 pages.  For the same reason, action #3 results
always in manages_pages being 0.

Action #5 and #6 are performed later on when onlining the pages:
 online_pages()->move_pfn_range_to_zone()->init_currently_empty_zone()
 online_pages()->move_pfn_range_to_zone()->memmap_init_zone()

This patch does two things:

First, moves the node/zone initializtion to their own function, so it
allows us to create a small version of free_area_init_core, where we only
perform:

1) Initialization of pgdat internals, such as spinlock, waitqueues and more
4) Initialization of some fields of the zone structure data

These two functions are: pgdat_init_internals() and zone_init_internals().

The second thing this patch does, is to introduce
free_area_init_core_hotplug(), the memhotplug version of
free_area_init_core():

Currently, we call free_area_init_node() from the memhotplug path.  In
there, we set some pgdat's fields, and call calculate_node_totalpages().
calculate_node_totalpages() calculates the # of pages the node has.

Since the node is either new, or we are re-using it, the zones belonging
to this node should not have any pages, so there is no point to calculate
this now.

Actually, we re-set these values to 0 later on with the calls to:

reset_node_managed_pages()
reset_node_present_pages()

The # of pages per node and the # of pages per zone will be calculated when
onlining the pages:

online_pages()->move_pfn_range()->move_pfn_range_to_zone()->resize_zone_range()
online_pages()->move_pfn_range()->move_pfn_range_to_zone()->resize_pgdat_range()

Also, since free_area_init_core/free_area_init_node will now only get called during early init, let us replace
__paginginit with __init, so their code gets freed up.

[osalvador@techadventures.net: fix section usage]
  Link: http://lkml.kernel.org/r/20180731101752.GA473@techadventures.net
[osalvador@suse.de: v6]
  Link: http://lkml.kernel.org/r/20180801122348.21588-6-osalvador@techadventures.net
Link: http://lkml.kernel.org/r/20180730101757.28058-5-osalvador@techadventures.netSigned-off-by: NOscar Salvador <osalvador@suse.de>
Reviewed-by: NPavel Tatashin <pasha.tatashin@oracle.com>
Acked-by: NMichal Hocko <mhocko@suse.com>
Acked-by: NVlastimil Babka <vbabka@suse.cz>
Cc: Pasha Tatashin <Pavel.Tatashin@microsoft.com>
Cc: Aaron Lu <aaron.lu@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

03e85f9d

mm/page_alloc: inline function to handle CONFIG_DEFERRED_STRUCT_PAGE_INIT · 0188dc98

由 Oscar Salvador 提交于 8月 21, 2018

Let us move the code between CONFIG_DEFERRED_STRUCT_PAGE_INIT to an inline
function.  Not having an ifdef in the function makes the code more
readable.

Link: http://lkml.kernel.org/r/20180730101757.28058-4-osalvador@techadventures.netSigned-off-by: NOscar Salvador <osalvador@suse.de>
Acked-by: NMichal Hocko <mhocko@suse.com>
Reviewed-by: NPavel Tatashin <pasha.tatashin@oracle.com>
Acked-by: NVlastimil Babka <vbabka@suse.cz>
Cc: Aaron Lu <aaron.lu@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Pasha Tatashin <Pavel.Tatashin@microsoft.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

0188dc98

mm: remove __paginginit · 7cc2a959

由 Pavel Tatashin 提交于 8月 21, 2018

__paginginit is the same thing as __meminit except for platforms without
sparsemem, there it is defined as __init.

Remove __paginginit and use __meminit.  Use __ref in one single function
that merges __meminit and __init sections: setup_usemap().

Link: http://lkml.kernel.org/r/20180801122348.21588-4-osalvador@techadventures.netSigned-off-by: NPavel Tatashin <pasha.tatashin@oracle.com>
Signed-off-by: NOscar Salvador <osalvador@suse.de>
Reviewed-by: NOscar Salvador <osalvador@suse.de>
Cc: Pasha Tatashin <Pavel.Tatashin@microsoft.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

7cc2a959

mm: access zone->node via zone_to_nid() and zone_set_nid() · c1093b74

由 Pavel Tatashin 提交于 8月 21, 2018

zone->node is configured only when CONFIG_NUMA=y, so it is a good idea to
have inline functions to access this field in order to avoid ifdef's in c
files.

Link: http://lkml.kernel.org/r/20180730101757.28058-3-osalvador@techadventures.netSigned-off-by: NPavel Tatashin <pasha.tatashin@oracle.com>
Signed-off-by: NOscar Salvador <osalvador@suse.de>
Reviewed-by: NOscar Salvador <osalvador@suse.de>
Acked-by: NMichal Hocko <mhocko@suse.com>
Acked-by: NVlastimil Babka <vbabka@suse.cz>
Cc: Aaron Lu <aaron.lu@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Pasha Tatashin <Pavel.Tatashin@microsoft.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

c1093b74

mm/page_alloc.c: move ifdefery out of free_area_init_core · ace1db39

由 Oscar Salvador 提交于 8月 21, 2018

Patch series "Refactor free_area_init_core and add
free_area_init_core_hotplug", v6.

This patchset does three things:

 1) Clean up/refactor free_area_init_core/free_area_init_node
    by moving the ifdefery out of the functions.
 2) Move the pgdat/zone initialization in free_area_init_core to its
    own function.
 3) Introduce free_area_init_core_hotplug, a small subset of
    free_area_init_core, which is only called from memhotlug code path. In this
    way, we have:

    free_area_init_core: called during early initialization
    free_area_init_core_hotplug: called whenever a new node is allocated/re-used (memhotplug path)

This patch (of 5):

Moving the #ifdefs out of the function makes it easier to follow.

Link: http://lkml.kernel.org/r/20180730101757.28058-2-osalvador@techadventures.netSigned-off-by: NOscar Salvador <osalvador@suse.de>
Acked-by: NMichal Hocko <mhocko@suse.com>
Reviewed-by: NPavel Tatashin <pasha.tatashin@oracle.com>
Acked-by: NVlastimil Babka <vbabka@suse.cz>
Cc: Pasha Tatashin <Pavel.Tatashin@microsoft.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Aaron Lu <aaron.lu@intel.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

ace1db39

18 8月, 2018 4 次提交

mm, page_alloc: double zone's batchsize · d8a759b5

由 Aaron Lu 提交于 8月 17, 2018

To improve page allocator's performance for order-0 pages, each CPU has
a Per-CPU-Pageset(PCP) per zone. Whenever an order-0 page is needed,
PCP will be checked first before asking pages from Buddy. When PCP is
used up, a batch of pages will be fetched from Buddy to improve
performance and the size of batch can affect performance.

zone's batch size gets doubled last time by commit ba56e91c("mm:
page_alloc: increase size of per-cpu-pages") over ten years ago. Since
then, CPU has envolved a lot and CPU's cache sizes also increased.

Dave Hansen is concerned the current batch size doesn't fit well with
modern hardware and suggested me to do two things: first, use a page
allocator intensive benchmark, e.g. will-it-scale/page_fault1 to find
out how performance changes with different batch sizes on various
machines and then choose a new default batch size; second, see how this
new batch size work with other workloads.

In the first test, we saw performance gains on high-core-count systems
and little to no effect on older systems with more modest core counts.
In this phase's test data, two candidates: 63 and 127 are chosen.

In the second step, ebizzy, oltp, kbuild, pigz, netperf, vm-scalability
and more will-it-scale sub-tests are tested to see how these two
candidates work with these workloads and decides a new default according
to their results.

Most test results are flat. will-it-scale/page_fault2 process mode has
10%-18% performance increase on 4-sockets Skylake and Broadwell.
vm-scalability/lru-file-mmap-read has 17%-47% performance increase for
4-sockets servers while for 2-sockets servers, it caused 3%-8% performance
drop. Further analysis showed that, with a larger pcp->batch and thus
larger pcp->high(the relationship of pcp->high=6 * pcp->batch is
maintained in this patch), zone lock contention shifted to LRU add side
lock contention and that caused performance drop. This performance drop
might be mitigated by others' work on optimizing LRU lock.

Another downside of increasing pcp->batch is, when PCP is used up and need
to fetch a batch of pages from Buddy, since batch is increased, that time
can be longer than before. My understanding is, this doesn't affect
slowpath where direct reclaim and compaction dominates. For fastpath,
throughput is a win(according to will-it-scale/page_fault1) but worst
latency can be larger now.

Overall, I think double the batch size from 31 to 63 is relatively safe
and provide good performance boost for high-core-count systems.

The two phase's test results are listed below(all tests are done with THP
disabled).

Phase one(will-it-scale/page_fault1) test results:

Skylake-EX: increased batch size has a good effect on zone->lock
contention, though LRU contention will rise at the same time and
limited the final performance increase.

batch score change zone_contention lru_contention total_contention
31 15345900 +0.00% 64% 8% 72%
53 17903847 +16.67% 32% 38% 70%
63 17992886 +17.25% 24% 45% 69%
73 18022825 +17.44% 10% 61% 71%
119 18023401 +17.45% 4% 66% 70%
127 18029012 +17.48% 3% 66% 69%
137 18036075 +17.53% 4% 66% 70%
165 18035964 +17.53% 2% 67% 69%
188 18101105 +17.95% 2% 67% 69%
223 18130951 +18.15% 2% 67% 69%
255 18118898 +18.07% 2% 67% 69%
267 18101559 +17.96% 2% 67% 69%
299 18160468 +18.34% 2% 68% 70%
320 18139845 +18.21% 2% 67% 69%
393 18160869 +18.34% 2% 68% 70%
424 18170999 +18.41% 2% 68% 70%
458 18144868 +18.24% 2% 68% 70%
467 18142366 +18.22% 2% 68% 70%
498 18154549 +18.30% 1% 68% 69%
511 18134525 +18.17% 1% 69% 70%

Broadwell-EX: similar pattern as Skylake-EX.

batch score change zone_contention lru_contention total_contention
31 16703983 +0.00% 67% 7% 74%
53 18195393 +8.93% 43% 28% 71%
63 18288885 +9.49% 38% 33% 71%
73 18344329 +9.82% 35% 37% 72%
119 18535529 +10.96% 24% 46% 70%
127 18513596 +10.83% 23% 48% 71%
137 18514327 +10.84% 23% 48% 71%
165 18511840 +10.82% 22% 49% 71%
188 18593478 +11.31% 17% 53% 70%
223 18601667 +11.36% 17% 52% 69%
255 18774825 +12.40% 12% 58% 70%
267 18754781 +12.28% 9% 60% 69%
299 18892265 +13.10% 7% 63% 70%
320 18873812 +12.99% 8% 62% 70%
393 18891174 +13.09% 6% 64% 70%
424 18975108 +13.60% 6% 64% 70%
458 18932364 +13.34% 8% 62% 70%
467 18960891 +13.51% 5% 65% 70%
498 18944526 +13.41% 5% 64% 69%
511 18960839 +13.51% 5% 64% 69%

Skylake-EP: although increased batch reduced zone->lock contention, but
the effect is not as good as EX: zone->lock contention is still as high as
20% with a very high batch value instead of 1% on Skylake-EX or 5% on
Broadwell-EX. Also, total_contention actually decreased with a higher
batch but that doesn't translate to performance increase.

batch score change zone_contention lru_contention total_contention
31 9554867 +0.00% 66% 3% 69%
53 9855486 +3.15% 63% 3% 66%
63 9980145 +4.45% 62% 4% 66%
73 10092774 +5.63% 62% 5% 67%
119 10310061 +7.90% 45% 19% 64%
127 10342019 +8.24% 42% 19% 61%
137 10358182 +8.41% 42% 21% 63%
165 10397060 +8.81% 37% 24% 61%
188 10341808 +8.24% 34% 26% 60%
223 10349135 +8.31% 31% 27% 58%
255 10327189 +8.08% 28% 29% 57%
267 10344204 +8.26% 27% 29% 56%
299 10325043 +8.06% 25% 30% 55%
320 10310325 +7.91% 25% 31% 56%
393 10293274 +7.73% 21% 31% 52%
424 10311099 +7.91% 21% 32% 53%
458 10321375 +8.02% 21% 32% 53%
467 10303881 +7.84% 21% 32% 53%
498 10332462 +8.14% 20% 33% 53%
511 10325016 +8.06% 20% 32% 52%

Broadwell-EP: zone->lock and lru lock had an agreement to make sure
performance doesn't increase and they successfully managed to keep total
contention at 70%.

batch score change zone_contention lru_contention total_contention
31 10121178 +0.00% 19% 50% 69%
53 10142366 +0.21% 6% 63% 69%
63 10117984 -0.03% 11% 58% 69%
73 10123330 +0.02% 7% 63% 70%
119 10108791 -0.12% 2% 67% 69%
127 10166074 +0.44% 3% 66% 69%
137 10141574 +0.20% 3% 66% 69%
165 10154499 +0.33% 2% 68% 70%
188 10124921 +0.04% 2% 67% 69%
223 10137399 +0.16% 2% 67% 69%
255 10143289 +0.22% 0% 68% 68%
267 10123535 +0.02% 1% 68% 69%
299 10140952 +0.20% 0% 68% 68%
320 10163170 +0.41% 0% 68% 68%
393 10000633 -1.19% 0% 69% 69%
424 10087998 -0.33% 0% 69% 69%
458 10187116 +0.65% 0% 69% 69%
467 10146790 +0.25% 0% 69% 69%
498 10197958 +0.76% 0% 69% 69%
511 10152326 +0.31% 0% 69% 69%

Haswell-EP: similar to Broadwell-EP.

batch score change zone_contention lru_contention total_contention
31 10442205 +0.00% 14% 48% 62%
53 10442255 +0.00% 5% 57% 62%
63 10452059 +0.09% 6% 57% 63%
73 10482349 +0.38% 5% 59% 64%
119 10454644 +0.12% 3% 60% 63%
127 10431514 -0.10% 3% 59% 62%
137 10423785 -0.18% 3% 60% 63%
165 10481216 +0.37% 2% 61% 63%
188 10448755 +0.06% 2% 61% 63%
223 10467144 +0.24% 2% 61% 63%
255 10480215 +0.36% 2% 61% 63%
267 10484279 +0.40% 2% 61% 63%
299 10466450 +0.23% 2% 61% 63%
320 10452578 +0.10% 2% 61% 63%
393 10499678 +0.55% 1% 62% 63%
424 10481454 +0.38% 1% 62% 63%
458 10473562 +0.30% 1% 62% 63%
467 10484269 +0.40% 0% 62% 62%
498 10505599 +0.61% 0% 62% 62%
511 10483395 +0.39% 0% 62% 62%

Westmere-EP: contention is pretty small so not interesting. Note too high
a batch value could hurt performance.

batch score change zone_contention lru_contention total_contention
31 4831523 +0.00% 2% 3% 5%
53 4834086 +0.05% 2% 4% 6%
63 4834262 +0.06% 2% 3% 5%
73 48328518 +0.03% 2% 4% 6%
119 4830534 -0.02% 1% 3% 4%
127 4827461 -0.08% 1% 4% 5%
137 4827459 -0.08% 1% 3% 4%
165 4820534 -0.23% 0% 4% 4%
188 4817947 -0.28% 0% 3% 3%
223 4809671 -0.45% 0% 3% 3%
255 4802463 -0.60% 0% 4% 4%
267 4801634 -0.62% 0% 3% 3%
299 4798047 -0.69% 0% 3% 3%
320 4793084 -0.80% 0% 3% 3%
393 4785877 -0.94% 0% 3% 3%
424 4782911 -1.01% 0% 3% 3%
458 4779346 -1.08% 0% 3% 3%
467 4780306 -1.06% 0% 3% 3%
498 4780589 -1.05% 0% 3% 3%
511 4773724 -1.20% 0% 3% 3%

Skylake-Desktop: similar to Westmere-EP, nothing interesting.

batch score change zone_contention lru_contention total_contention
31 3906608 +0.00% 2% 3% 5%
53 3940164 +0.86% 2% 3% 5%
63 3937289 +0.79% 2% 3% 5%
73 3940201 +0.86% 2% 3% 5%
119 3933240 +0.68% 2% 3% 5%
127 3930514 +0.61% 2% 4% 6%
137 3938639 +0.82% 0% 3% 3%
165 3908755 +0.05% 0% 3% 3%
188 3905621 -0.03% 0% 3% 3%
223 3903015 -0.09% 0% 4% 4%
255 3889480 -0.44% 0% 3% 3%
267 3891669 -0.38% 0% 4% 4%
299 3898728 -0.20% 0% 4% 4%
320 3894547 -0.31% 0% 4% 4%
393 3875137 -0.81% 0% 4% 4%
424 3874521 -0.82% 0% 3% 3%
458 3880432 -0.67% 0% 4% 4%
467 3888715 -0.46% 0% 3% 3%
498 3888633 -0.46% 0% 4% 4%
511 3875305 -0.80% 0% 5% 5%

Haswell-Desktop: zone->lock is pretty low as other desktops, though lru
contention is higher than other desktops.

batch score change zone_contention lru_contention total_contention
31 3511158 +0.00% 2% 5% 7%
53 3555445 +1.26% 2% 6% 8%
63 3561082 +1.42% 2% 6% 8%
73 3547218 +1.03% 2% 6% 8%
119 3571319 +1.71% 1% 7% 8%
127 3549375 +1.09% 0% 6% 6%
137 3560233 +1.40% 0% 6% 6%
165 3555176 +1.25% 2% 6% 8%
188 3551501 +1.15% 0% 8% 8%
223 3531462 +0.58% 0% 7% 7%
255 3570400 +1.69% 0% 7% 7%
267 3532235 +0.60% 1% 8% 9%
299 3562326 +1.46% 0% 6% 6%
320 3553569 +1.21% 0% 8% 8%
393 3539519 +0.81% 0% 7% 7%
424 3549271 +1.09% 0% 8% 8%
458 3528885 +0.50% 0% 8% 8%
467 3526554 +0.44% 0% 7% 7%
498 3525302 +0.40% 0% 9% 9%
511 3527556 +0.47% 0% 8% 8%

Sandybridge-Desktop: the 0% contention isn't accurate but caused by
dropped fractional part. Since multiple contention path's contentions
are all under 1% here, with some arithmetic operations like add, the
final deviation could be as large as 3%.

batch score change zone_contention lru_contention total_contention
31 1744495 +0.00% 0% 0% 0%
53 1755341 +0.62% 0% 0% 0%
63 1758469 +0.80% 0% 0% 0%
73 1759626 +0.87% 0% 0% 0%
119 1770417 +1.49% 0% 0% 0%
127 1768252 +1.36% 0% 0% 0%
137 1767848 +1.34% 0% 0% 0%
165 1765088 +1.18% 0% 0% 0%
188 1766918 +1.29% 0% 0% 0%
223 1767866 +1.34% 0% 0% 0%
255 1768074 +1.35% 0% 0% 0%
267 1763187 +1.07% 0% 0% 0%
299 1765620 +1.21% 0% 0% 0%
320 1767603 +1.32% 0% 0% 0%
393 1764612 +1.15% 0% 0% 0%
424 1758476 +0.80% 0% 0% 0%
458 1758593 +0.81% 0% 0% 0%
467 1757915 +0.77% 0% 0% 0%
498 1753363 +0.51% 0% 0% 0%
511 1755548 +0.63% 0% 0% 0%

Phase two test results:
Note: all percent change is against base(batch=31).

ebizzy.throughput (higer is better)

machine batch=31 batch=63 batch=127
lkp-skl-4sp1 2410037±7% 2600451±2% +7.9% 2602878 +8.0%
lkp-bdw-ex1 1493328 1489243 -0.3% 1492145 -0.1%
lkp-skl-2sp2 1329674 1345891 +1.2% 1351056 +1.6%
lkp-bdw-ep2 711511 711511 0.0% 710708 -0.1%
lkp-wsm-ep2 75750 75528 -0.3% 75441 -0.4%
lkp-skl-d01 264126 262791 -0.5% 264113 +0.0%
lkp-hsw-d01 176601 176328 -0.2% 176368 -0.1%
lkp-sb02 98937 98937 +0.0% 99030 +0.1%

kbuild.buildtime (less is better)

machine batch=31 batch=63 batch=127
lkp-skl-4sp1 107.00 107.67 +0.6% 107.11 +0.1%
lkp-bdw-ex1 97.33 97.33 +0.0% 97.42 +0.1%
lkp-skl-2sp2 180.00 179.83 -0.1% 179.83 -0.1%
lkp-bdw-ep2 178.17 179.17 +0.6% 177.50 -0.4%
lkp-wsm-ep2 737.00 738.00 +0.1% 738.00 +0.1%
lkp-skl-d01 642.00 653.00 +1.7% 653.00 +1.7%
lkp-hsw-d01 1310.00 1316.00 +0.5% 1311.00 +0.1%

netperf/TCP_STREAM.Throughput_total_Mbps (higher is better)

machine batch=31 batch=63 batch=127
lkp-skl-4sp1 948790 947144 -0.2% 948333 -0.0%
lkp-bdw-ex1 904224 904366 +0.0% 904926 +0.1%
lkp-skl-2sp2 239731 239607 -0.1% 239565 -0.1%
lk-bdw-ep2 365764 365933 +0.0% 365951 +0.1%
lkp-wsm-ep2 93736 93803 +0.1% 93808 +0.1%
lkp-skl-d01 77314 77303 -0.0% 77375 +0.1%
lkp-hsw-d01 58617 60387 +3.0% 60208 +2.7%
lkp-sb02 29990 30137 +0.5% 30103 +0.4%

oltp.transactions (higer is better)

machine batch=31 batch=63 batch=127
lkp-bdw-ex1 9073276 9100377 +0.3% 9036344 -0.4%
lkp-skl-2sp2 8898717 8852054 -0.5% 8894459 -0.0%
lkp-bdw-ep2 13426155 13384654 -0.3% 13333637 -0.7%
lkp-hsw-ep2 13146314 13232784 +0.7% 13193163 +0.4%
lkp-wsm-ep2 5035355 5019348 -0.3% 5033418 -0.0%
lkp-skl-d01 418485 4413339 -0.1% 4419039 +0.0%
lkp-hsw-d01 3517817±5% 3396120±3% -3.5% 3455138±3% -1.8%

pigz.throughput (higer is better)

machine batch=31 batch=63 batch=127
lkp-skl-4sp1 1.513e+08 1.507e+08 -0.4% 1.511e+08 -0.2%
lkp-bdw-ex1 2.060e+08 2.052e+08 -0.4% 2.044e+08 -0.8%
lkp-skl-2sp2 8.836e+08 8.845e+08 +0.1% 8.836e+08 -0.0%
lkp-bdw-ep2 8.275e+08 8.464e+08 +2.3% 8.330e+08 +0.7%
lkp-wsm-ep2 2.224e+08 2.221e+08 -0.2% 2.218e+08 -0.3%
lkp-skl-d01 1.177e+08 1.177e+08 -0.0% 1.176e+08 -0.1%
lkp-hsw-d01 1.154e+08 1.154e+08 +0.1% 1.154e+08 -0.0%
lkp-sb02 0.633e+08 0.633e+08 +0.1% 0.633e+08 +0.0%

will-it-scale.malloc1.processes (higher is better)

machine batch=31 batch=63 batch=127
lkp-skl-4sp1 620181 620484 +0.0% 620240 +0.0%
lkp-bdw-ex1 1403610 1401201 -0.2% 1417900 +1.0%
lkp-skl-2sp2 1288097 1284145 -0.3% 1283907 -0.3%
lkp-bdw-ep2 1427879 1427675 -0.0% 1428266 +0.0%
lkp-hsw-ep2 1362546 1353965 -0.6% 1354759 -0.6%
lkp-wsm-ep2 2099657 2107576 +0.4% 2100226 +0.0%
lkp-skl-d01 1476835 1476358 -0.0% 1474487 -0.2%
lkp-hsw-d01 1308810 1303429 -0.4% 1301299 -0.6%
lkp-sb02 589286 589284 -0.0% 588101 -0.2%

will-it-scale.malloc1.threads (higher is better)
machine batch=31 batch=63 batch=127
lkp-skl-4sp1 21289 21125 -0.8% 21241 -0.2%
lkp-bdw-ex1 28114 28089 -0.1% 28007 -0.4%
lkp-skl-2sp2 91866 91946 +0.1% 92723 +0.9%
lkp-bdw-ep2 37637 37501 -0.4% 37317 -0.9%
lkp-hsw-ep2 43673 43590 -0.2% 43754 +0.2%
lkp-wsm-ep2 28577 28298 -1.0% 28545 -0.1%
lkp-skl-d01 175277 173343 -1.1% 173082 -1.3%
lkp-hsw-d01 130303 129566 -0.6% 129250 -0.8%
lkp-sb02 113742±3% 116911 +2.8% 116417±3% +2.4%

will-it-scale.malloc2.processes (higer is better)

machine batch=31 batch=63 batch=127
lkp-skl-4sp1 1.206e+09 1.206e+09 -0.0% 1.206e+09 +0.0%
lkp-bdw-ex1 1.319e+09 1.319e+09 -0.0% 1.319e+09 +0.0%
lkp-skl-2sp2 8.000e+08 8.021e+08 +0.3% 7.995e+08 -0.1%
lkp-bdw-ep2 6.582e+08 6.634e+08 +0.8% 6.513e+08 -1.1%
lkp-hsw-ep2 6.671e+08 6.669e+08 -0.0% 6.665e+08 -0.1%
lkp-wsm-ep2 1.805e+08 1.806e+08 +0.0% 1.804e+08 -0.1%
lkp-skl-d01 1.611e+08 1.611e+08 -0.0% 1.610e+08 -0.0%
lkp-hsw-d01 1.333e+08 1.332e+08 -0.0% 1.332e+08 -0.0%
lkp-sb02 82485104 82478206 -0.0% 82473546 -0.0%

will-it-scale.malloc2.threads (higer is better)

machine batch=31 batch=63 batch=127
lkp-skl-4sp1 1.574e+09 1.574e+09 -0.0% 1.574e+09 -0.0%
lkp-bdw-ex1 1.737e+09 1.737e+09 +0.0% 1.737e+09 -0.0%
lkp-skl-2sp2 9.161e+08 9.162e+08 +0.0% 9.181e+08 +0.2%
lkp-bdw-ep2 7.856e+08 8.015e+08 +2.0% 8.113e+08 +3.3%
lkp-hsw-ep2 6.908e+08 6.904e+08 -0.1% 6.907e+08 -0.0%
lkp-wsm-ep2 2.409e+08 2.409e+08 +0.0% 2.409e+08 -0.0%
lkp-skl-d01 1.199e+08 1.199e+08 -0.0% 1.199e+08 -0.0%
lkp-hsw-d01 1.029e+08 1.029e+08 -0.0% 1.029e+08 +0.0%
lkp-sb02 68081213 68061423 -0.0% 68076037 -0.0%

will-it-scale.page_fault2.processes (higer is better)

machine batch=31 batch=63 batch=127
lkp-skl-4sp1 14509125±4% 16472364 +13.5% 17123117 +18.0%
lkp-bdw-ex1 14736381 16196588 +9.9% 16364011 +11.0%
lkp-skl-2sp2 6354925 6435444 +1.3% 6436644 +1.3%
lkp-bdw-ep2 8749584 8834422 +1.0% 8827179 +0.9%
lkp-hsw-ep2 8762591 8845920 +1.0% 8825697 +0.7%
lkp-wsm-ep2 3036083 3030428 -0.2% 3021741 -0.5%
lkp-skl-d01 2307834 2304731 -0.1% 2286142 -0.9%
lkp-hsw-d01 1806237 1800786 -0.3% 1795943 -0.6%
lkp-sb02 842616 837844 -0.6% 833921 -1.0%

will-it-scale.page_fault2.threads

machine batch=31 batch=63 batch=127
lkp-skl-4sp1 1623294 1615132±2% -0.5% 1656777 +2.1%
lkp-bdw-ex1 1995714 2025948 +1.5% 2113753±3% +5.9%
lkp-skl-2sp2 2346708 2415591 +2.9% 2416919 +3.0%
lkp-bdw-ep2 2342564 2344882 +0.1% 2300206 -1.8%
lkp-hsw-ep2 1820658 1831681 +0.6% 1844057 +1.3%
lkp-wsm-ep2 1725482 1733774 +0.5% 1740517 +0.9%
lkp-skl-d01 1832833 1823628 -0.5% 1806489 -1.4%
lkp-hsw-d01 1427913 1427287 -0.0% 1420226 -0.5%
lkp-sb02 750626 748615 -0.3% 746621 -0.5%

will-it-scale.page_fault3.processes (higher is better)

machine batch=31 batch=63 batch=127
lkp-skl-4sp1 24382726 24400317 +0.1% 24668774 +1.2%
lkp-bdw-ex1 35399750 35683124 +0.8% 35829492 +1.2%
lkp-skl-2sp2 28136820 28068248 -0.2% 28147989 +0.0%
lkp-bdw-ep2 37269077 37459490 +0.5% 37373073 +0.3%
lkp-hsw-ep2 36224967 36114085 -0.3% 36104908 -0.3%
lkp-wsm-ep2 16820457 16911005 +0.5% 16968596 +0.9%
lkp-skl-d01 7721138 7725904 +0.1% 7756740 +0.5%
lkp-hsw-d01 7611979 7650928 +0.5% 7651323 +0.5%
lkp-sb02 3781546 3796502 +0.4% 3796827 +0.4%

will-it-scale.page_fault3.threads (higer is better)

machine batch=31 batch=63 batch=127
lkp-skl-4sp1 1865820±3% 1900917±2% +1.9% 1826245±4% -2.1%
lkp-bdw-ex1 3094060 3148326 +1.8% 3150036 +1.8%
lkp-skl-2sp2 3952940 3953898 +0.0% 3989360 +0.9%
lkp-bdw-ep2 3420373±3% 3643964 +6.5% 3644910±5% +6.6%
lkp-hsw-ep2 2609635±2% 2582310±3% -1.0% 2780459 +6.5%
lkp-wsm-ep2 4395001 4417196 +0.5% 4432499 +0.9%
lkp-skl-d01 5363977 5400003 +0.7% 5411370 +0.9%
lkp-hsw-d01 5274131 5311294 +0.7% 5319359 +0.9%
lkp-sb02 2917314 2913004 -0.1% 2935286 +0.6%

will-it-scale.read1.processes (higer is better)

machine batch=31 batch=63 batch=127
lkp-skl-4sp1 73762279±14% 69322519±10% -6.0% 69349855±13% -6.0% (result unstable)
lkp-bdw-ex1 1.701e+08 1.704e+08 +0.1% 1.705e+08 +0.2%
lkp-skl-2sp2 63111570 63113953 +0.0% 63836573 +1.1%
lkp-bdw-ep2 79247409 79424610 +0.2% 78012656 -1.6%
lkp-hsw-ep2 67677026 68308800 +0.9% 67539106 -0.2%
lkp-wsm-ep2 13339630 13939817 +4.5% 13766865 +3.2%
lkp-skl-d01 10969487 10972650 +0.0% no data
lkp-hsw-d01 9857342±2% 10080592±2% +2.3% 10131560 +2.8%
lkp-sb02 5189076 5197473 +0.2% 5163253 -0.5%

will-it-scale.read1.threads (higher is better)

machine batch=31 batch=63 batch=127
lkp-skl-4sp1 62468045±12% 73666726±7% +17.9% 79553123±12% +27.4% (result unstable)
lkp-bdw-ex1 1.62e+08 1.624e+08 +0.3% 1.614e+08 -0.3%
lkp-skl-2sp2 58319780 59181032 +1.5% 59821353 +2.6%
lkp-bdw-ep2 74057992 75698171 +2.2% 74990869 +1.3%
lkp-hsw-ep2 63672959 63639652 -0.1% 64387051 +1.1%
lkp-wsm-ep2 13489943 13526058 +0.3% 13259032 -1.7%
lkp-skl-d01 10297906 10338796 +0.4% 10407328 +1.1%
lkp-hsw-d01 9636721 9667376 +0.3% 9341147 -3.1%
lkp-sb02 4801938 4804496 +0.1% 4802290 +0.0%

will-it-scale.write1.processes (higer is better)

machine batch=31 batch=63 batch=127
lkp-skl-4sp1 1.111e+08 1.104e+08±2% -0.7% 1.122e+08±2% +1.0%
lkp-bdw-ex1 1.392e+08 1.399e+08 +0.5% 1.397e+08 +0.4%
lkp-skl-2sp2 59369233 58994841 -0.6% 58715168 -1.1%
lkp-bdw-ep2 61820979 CPU throttle 63593123 +2.9%
lkp-hsw-ep2 57897587 57435605 -0.8% 56347450 -2.7%
lkp-wsm-ep2 7814203 7918017±2% +1.3% 7669068 -1.9%
lkp-skl-d01 8886557 8971422 +1.0% 8818366 -0.8%
lkp-hsw-d01 9171001±5% 9189915 +0.2% 9483909 +3.4%
lkp-sb02 4475406 4475294 -0.0% 4501756 +0.6%

will-it-scale.write1.threads (higer is better)

machine batch=31 batch=63 batch=127
lkp-skl-4sp1 1.058e+08 1.055e+08±2% -0.2% 1.065e+08 +0.7%
lkp-bdw-ex1 1.316e+08 1.300e+08 -1.2% 1.308e+08 -0.6%
lkp-skl-2sp2 54492421 56086678 +2.9% 55975657 +2.7%
lkp-bdw-ep2 59360449 59003957 -0.6% 58101262 -2.1%
lkp-hsw-ep2 53346346±2% 52530876 -1.5% 52902487 -0.8%
lkp-wsm-ep2 7774006 7800092±2% +0.3% 7558833 -2.8%
lkp-skl-d01 8346174 8235695 -1.3% no data
lkp-hsw-d01 8636244 8655731 +0.2% 8658868 +0.3%
lkp-sb02 4181820 4204107 +0.5% 4182992 +0.0%

vm-scalability.anon-r-rand.throughput (higher is better)

machine batch=31 batch=63 batch=127
lkp-skl-4sp1 11933873±3% 12356544±2% +3.5% 12188624 +2.1%
lkp-bdw-ex1 7114424±2% 7330949±2% +3.0% 7392419 +3.9%
lkp-skl-2sp2 6773277±5% 6492332±8% -4.1% 6543962 -3.4%
lkp-bdw-ep2 7133846±4% 7233508 +1.4% 7013518±3% -1.7%
lkp-hsw-ep2 4576626 4527098 -1.1% 4551679 -0.5%
lkp-wsm-ep2 2583599 2592492 +0.3% 2588039 +0.2%
lkp-hsw-d01 998199±2% 1028311 +3.0% 1006460±2% +0.8%
lkp-sb02 570572 567854 -0.5% 568449 -0.4%

vm-scalability.anon-r-rand-mt.throughput (higher is better)

machine batch=31 batch=63 batch=127
lkp-skl-4sp1 1789419 1787830 -0.1% 1788208 -0.1%
lkp-bdw-ex1 3492595±2% 3554966±2% +1.8% 3558835±3% +1.9%
lkp-skl-2sp2 3856238±2% 3975403±4% +3.1% 3994600 +3.6%
lkp-bdw-ep2 3726963±11% 3809292±6% +2.2% 3871924±4% +3.9%
lkp-hsw-ep2 2131760±3% 2033578±4% -4.6% 2130727±6% -0.0%
lkp-wsm-ep2 2369731 2368384 -0.1% 2370252 +0.0%
lkp-skl-d01 1207128 1206220 -0.1% 1205801 -0.1%
lkp-hsw-d01 964317 992329±2% +2.9% 992099±2% +2.9%
lkp-sb02 567137 567346 +0.0% 566144 -0.2%

vm-scalability.lru-file-mmap-read.throughput (higher is better)

machine batch=31 batch=63 batch=127
lkp-skl-4sp1 19560469±6% 23018999 +17.7% 23418800 +19.7%
lkp-bdw-ex1 17769135±14% 26141676±3% +47.1% 26284723±5% +47.9%
lkp-skl-2sp2 14056512 13578884 -3.4% 13146214 -6.5%
lkp-bdw-ep2 15336542 14737654 -3.9% 14088159 -8.1%
lkp-hsw-ep2 16275498 15756296 -3.2% 15018090 -7.7%
lkp-wsm-ep2 11272160 11237231 -0.3% 11310047 +0.3%
lkp-skl-d01 7322119 7324569 +0.0% 7184148 -1.9%
lkp-hsw-d01 6449234 6404542 -0.7% 6356141 -1.4%
lkp-sb02 3517943 3520668 +0.1% 3527309 +0.3%

vm-scalability.lru-file-mmap-read-rand.throughput (higher is better)

machine batch=31 batch=63 batch=127
lkp-skl-4sp1 1689052 1697553 +0.5% 1698726 +0.6%
lkp-bdw-ex1 1675246 1699764 +1.5% 1712226 +2.2%
lkp-skl-2sp2 1800533 1799749 -0.0% 1800581 +0.0%
lkp-bdw-ep2 1807422 1807758 +0.0% 1804932 -0.1%
lkp-hsw-ep2 1809807 1808781 -0.1% 1807811 -0.1%
lkp-wsm-ep2 1800198 1802434 +0.1% 1801236 +0.1%
lkp-skl-d01 696689 695537 -0.2% 694106 -0.4%
lkp-hsw-d01 698364 698666 +0.0% 696686 -0.2%
lkp-sb02 258939 258787 -0.1% 258199 -0.3%

Link: http://lkml.kernel.org/r/20180711055855.29072-1-aaron.lu@intel.comSigned-off-by: NAaron Lu <aaron.lu@intel.com>
Suggested-by: NDave Hansen <dave.hansen@intel.com>
Acked-by: NMichal Hocko <mhocko@suse.com>
Acked-by: NJesper Dangaard Brouer <brouer@redhat.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Kemi Wang <kemi.wang@intel.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

d8a759b5

mm: drop VM_BUG_ON from __get_free_pages · 9ea9a680

由 Michal Hocko 提交于 8月 17, 2018

There is no real reason to blow up just because the caller doesn't know
that __get_free_pages cannot return highmem pages.  Simply fix that up
silently.  Even if we have some confused users such a fixup will not be
harmful.

[akpm@linux-foundation.org: mask off __GFP_HIGHMEM]
Link: http://lkml.kernel.org/r/20180622162841.25114-1-mhocko@kernel.orgSigned-off-by: NMichal Hocko <mhocko@suse.com>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Jiankang Chen <chenjiankang1@huawei.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Yisheng Xie <xieyisheng1@huawei.com>
Cc: Hanjun Guo <guohanjun@huawei.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

9ea9a680

mm, page_alloc: actually ignore mempolicies for high priority allocations · d6a24df0

由 Vlastimil Babka 提交于 8月 17, 2018

__alloc_pages_slowpath() has for a long time contained code to ignore
node restrictions from memory policies for high priority allocations.
The current code that resets the zonelist iterator however does
effectively nothing after commit 7810e678 ("mm, page_alloc: do not
break __GFP_THISNODE by zonelist reset") removed a buggy zonelist reset.
Even before that commit, mempolicy restrictions were still not ignored,
as they are passed in ac->nodemask which is untouched by the code.

We can either remove the code, or make it work as intended.  Since
ac->nodemask can be set from task's mempolicy via alloc_pages_current()
and thus also alloc_pages(), it may indeed affect kernel allocations,
and it makes sense to ignore it to allow progress for high priority
allocations.

Thus, this patch resets ac->nodemask to NULL in such cases.  This
assumes all callers can handle it (i.e.  there are no guarantees as in
the case of __GFP_THISNODE) which seems to be the case.  The same
assumption is already present in check_retry_cpuset() for some time.

The expected effect is that high priority kernel allocations in the
context of userspace tasks (e.g.  OOM victims) restricted by mempolicies
will have higher chance to succeed if they are restricted to nodes with
depleted memory, while there are other nodes with free memory left.

It's not a new intention, but for the first time the code will match the
intention, AFAICS.  It was intended by commit 183f6371 ("mm: ignore
mempolicies when using ALLOC_NO_WATERMARK") in v3.6 but I think it never
really worked, as mempolicy restriction was already encoded in nodemask,
not zonelist, at that time.

So originally that was for ALLOC_NO_WATERMARK only.  Then it was
adjusted by e46e7b77 ("mm, page_alloc: recalculate the preferred
zoneref if the context can ignore memory policies") and cd04ae1e
("mm, oom: do not rely on TIF_MEMDIE for memory reserves access") to the
current state.  So even GFP_ATOMIC would now ignore mempolicies after
the initial attempts fail - if the code worked as people thought it
does.

Link: http://lkml.kernel.org/r/20180612122624.8045-1-vbabka@suse.czSigned-off-by: NVlastimil Babka <vbabka@suse.cz>
Acked-by: NMichal Hocko <mhocko@suse.com>
Acked-by: NMel Gorman <mgorman@techsingularity.net>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

d6a24df0

mm: skip invalid pages block at a time in zero_resv_unresv() · 720e14eb

由 Pavel Tatashin 提交于 8月 17, 2018

The role of zero_resv_unavail() is to make sure that every struct page
that is allocated but is not backed by memory that is accessible by
kernel is zeroed and not in some uninitialized state.

Since struct pages are allocated in blocks (2M pages in x86 case), we
can skip pageblock_nr_pages at a time, when the first one is found to be
invalid.

This optimization may help since now on x86 every hole in e820 maps is
marked as reserved in memblock, and thus will go through this function.

This function is called before sched_clock() is initialized, so I used
my x86 early boot clock patches to measure the performance improvement.

With 1T hole on i7-8700 currently we would take 0.606918s of boot time,
but with this optimization 0.001103s.

Link: http://lkml.kernel.org/r/20180615155733.1175-1-pasha.tatashin@oracle.comSigned-off-by: NPavel Tatashin <pasha.tatashin@oracle.com>
Reviewed-by: NOscar Salvador <osalvador@suse.de>
Reviewed-by: NNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Pasha Tatashin <Pavel.Tatashin@microsoft.com>
Cc: Steven Sistare <steven.sistare@oracle.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

720e14eb

06 8月, 2018 2 次提交

PM / reboot: Eliminate race between reboot and suspend · 55f2503c

由 Pingfan Liu 提交于 7月 31, 2018

At present, "systemctl suspend" and "shutdown" can run in parrallel. A
system can suspend after devices_shutdown(), and resume. Then the shutdown
task goes on to power off. This causes many devices are not really shut
off. Hence replacing reboot_mutex with system_transition_mutex (renamed
from pm_mutex) to achieve the exclusion. The renaming of pm_mutex as
system_transition_mutex can be better to reflect the purpose of the mutex.
Signed-off-by: NPingfan Liu <kernelfans@gmail.com>
Acked-by: NPavel Machek <pavel@ucw.cz>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

55f2503c

mm: Allow non-direct-map arguments to free_reserved_area() · 0d834328

由 Dave Hansen 提交于 8月 02, 2018

free_reserved_area() takes pointers as arguments to show which addresses
should be freed.  However, it does this in a somewhat ambiguous way.  If it
gets a kernel direct map address, it always works.  However, if it gets an
address that is part of the kernel image alias mapping, it can fail.

It fails if all of the following happen:
 * The specified address is part of the kernel image alias
 * Poisoning is requested (forcing a memset())
 * The address is in a read-only portion of the kernel image

The memset() fails on the read-only mapping, of course.
free_reserved_area() *is* called both on the direct map and on kernel image
alias addresses.  We've just lucked out thus far that the kernel image
alias areas it gets used on are read-write.  I'm fairly sure this has been
just a happy accident.

It is quite easy to make free_reserved_area() work for all cases: just
convert the address to a direct map address before doing the memset(), and
do this unconditionally.  There is little chance of a regression here
because we previously did a virt_to_page() on the address for the memset,
so we know these are not highmem pages for which virt_to_page() would fail.
Signed-off-by: NDave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: keescook@google.com
Cc: aarcange@redhat.com
Cc: jgross@suse.com
Cc: jpoimboe@redhat.com
Cc: gregkh@linuxfoundation.org
Cc: peterz@infradead.org
Cc: hughd@google.com
Cc: torvalds@linux-foundation.org
Cc: bp@alien8.de
Cc: luto@kernel.org
Cc: ak@linux.intel.com
Cc: Kees Cook <keescook@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Andi Kleen <ak@linux.intel.com>
Link: https://lkml.kernel.org/r/20180802225826.1287AE3E@viggo.jf.intel.com

0d834328

17 7月, 2018 1 次提交

mm: don't do zero_resv_unavail if memmap is not allocated · d1b47a7c

由 Pavel Tatashin 提交于 7月 16, 2018

Moving zero_resv_unavail before memmap_init_zone(), caused a regression on
x86-32.

The cause is that we access struct pages before they are allocated when
CONFIG_FLAT_NODE_MEM_MAP is used.

free_area_init_nodes()
  zero_resv_unavail()
    mm_zero_struct_page(pfn_to_page(pfn)); <- struct page is not alloced
  free_area_init_node()
    if CONFIG_FLAT_NODE_MEM_MAP
      alloc_node_mem_map()
        memblock_virt_alloc_node_nopanic() <- struct page alloced here

On the other hand memblock_virt_alloc_node_nopanic() zeroes all the memory
that it returns, so we do not need to do zero_resv_unavail() here.

Fixes: e181ae0c ("mm: zero unavailable pages before memmap init")
Signed-off-by: NPavel Tatashin <pasha.tatashin@oracle.com>
Tested-by: NMatt Hart <matt@mattface.org>
Acked-by: NMichal Hocko <mhocko@suse.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

d1b47a7c

15 7月, 2018 1 次提交

mm: zero unavailable pages before memmap init · e181ae0c

由 Pavel Tatashin 提交于 7月 14, 2018

We must zero struct pages for memory that is not backed by physical
memory, or kernel does not have access to.

Recently, there was a change which zeroed all memmap for all holes in
e820.  Unfortunately, it introduced a bug that is discussed here:

  https://www.spinics.net/lists/linux-mm/msg156764.html

Linus, also saw this bug on his machine, and confirmed that reverting
commit 124049de ("x86/e820: put !E820_TYPE_RAM regions into
memblock.reserved") fixes the issue.

The problem is that we incorrectly zero some struct pages after they
were setup.

The fix is to zero unavailable struct pages prior to initializing of
struct pages.

A more detailed fix should come later that would avoid double zeroing
cases: one in __init_single_page(), the other one in
zero_resv_unavail().

Fixes: 124049de ("x86/e820: put !E820_TYPE_RAM regions into memblock.reserved")
Signed-off-by: NPavel Tatashin <pasha.tatashin@oracle.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

e181ae0c

15 6月, 2018 1 次提交

mm: use octal not symbolic permissions · 0825a6f9

由 Joe Perches 提交于 6月 14, 2018

mm/*.c files use symbolic and octal styles for permissions.

Using octal and not symbolic permissions is preferred by many as more
readable.

https://lkml.org/lkml/2016/8/2/1945

Prefer the direct use of octal for permissions.

Done using
$ scripts/checkpatch.pl -f --types=SYMBOLIC_PERMS --fix-inplace mm/*.c
and some typing.

Before:	 $ git grep -P -w "0[0-7]{3,3}" mm | wc -l
44
After:	 $ git grep -P -w "0[0-7]{3,3}" mm | wc -l
86

Miscellanea:

o Whitespace neatening around these conversions.

Link: http://lkml.kernel.org/r/2e032ef111eebcd4c5952bae86763b541d373469.1522102887.git.joe@perches.comSigned-off-by: NJoe Perches <joe@perches.com>
Acked-by: NDavid Rientjes <rientjes@google.com>
Acked-by: NMichal Hocko <mhocko@suse.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

0825a6f9

08 6月, 2018 2 次提交

mm, page_alloc: do not break __GFP_THISNODE by zonelist reset · 7810e678

由 Vlastimil Babka 提交于 6月 07, 2018

In __alloc_pages_slowpath() we reset zonelist and preferred_zoneref for
allocations that can ignore memory policies.  The zonelist is obtained
from current CPU's node.  This is a problem for __GFP_THISNODE
allocations that want to allocate on a different node, e.g.  because the
allocating thread has been migrated to a different CPU.

This has been observed to break SLAB in our 4.4-based kernel, because
there it relies on __GFP_THISNODE working as intended.  If a slab page
is put on wrong node's list, then further list manipulations may corrupt
the list because page_to_nid() is used to determine which node's
list_lock should be locked and thus we may take a wrong lock and race.

Current SLAB implementation seems to be immune by luck thanks to commit
511e3a05 ("mm/slab: make cache_grow() handle the page allocated on
arbitrary node") but there may be others assuming that __GFP_THISNODE
works as promised.

We can fix it by simply removing the zonelist reset completely.  There
is actually no reason to reset it, because memory policies and cpusets
don't affect the zonelist choice in the first place.  This was different
when commit 183f6371 ("mm: ignore mempolicies when using
ALLOC_NO_WATERMARK") introduced the code, as mempolicies provided their
own restricted zonelists.

We might consider this for 4.17 although I don't know if there's
anything currently broken.

SLAB is currently not affected, but in kernels older than 4.7 that don't
yet have 511e3a05 ("mm/slab: make cache_grow() handle the page
allocated on arbitrary node") it is.  That's at least 4.4 LTS.  Older
ones I'll have to check.

So stable backports should be more important, but will have to be
reviewed carefully, as the code went through many changes.  BTW I think
that also the ac->preferred_zoneref reset is currently useless if we
don't also reset ac->nodemask from a mempolicy to NULL first (which we
probably should for the OOM victims etc?), but I would leave that for a
separate patch.

Link: http://lkml.kernel.org/r/20180525130853.13915-1-vbabka@suse.czSigned-off-by: NVlastimil Babka <vbabka@suse.cz>
Fixes: 183f6371 ("mm: ignore mempolicies when using ALLOC_NO_WATERMARK")
Acked-by: NMel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

7810e678

mm: combine LRU and main union in struct page · 4da1984e

由 Matthew Wilcox 提交于 6月 07, 2018

This gives us five words of space in a single union in struct page.  The
compound_mapcount moves position (from offset 24 to offset 20) on 64-bit
systems, but that does not seem likely to cause any trouble.

Link: http://lkml.kernel.org/r/20180518194519.3820-11-willy@infradead.orgSigned-off-by: NMatthew Wilcox <mawilcox@microsoft.com>
Acked-by: NVlastimil Babka <vbabka@suse.cz>
Acked-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

4da1984e