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  1. 23 10月, 2019 1 次提交
  3. 21 10月, 2019 2 次提交
  5. 10 10月, 2019 1 次提交
  7. 07 10月, 2019 1 次提交
  9. 05 10月, 2019 4 次提交
  11. 04 10月, 2019 1 次提交
  13. 03 10月, 2019 3 次提交
    • M
      block: pg: add header include guard · 3a4b46c3
      由 Masahiro Yamada 提交于 
      Add a header include guard just in case.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>
      3a4b46c3
    • M
      drm/amdgpu: return tcc_disabled_mask to userspace · 815fb4c9
      由 Marek Olšák 提交于 
      UMDs need this for correct programming of harvested chips.
Signed-off-by: NMarek Olšák <marek.olsak@amd.com>
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>
      815fb4c9
    • V
      net: dsa: sja1105: Fix sleeping while atomic in .port_hwtstamp_set · 3e8db7e5
      由 Vladimir Oltean 提交于 
      Currently this stack trace can be seen with CONFIG_DEBUG_ATOMIC_SLEEP=y:

[   41.568348] BUG: sleeping function called from invalid context at kernel/locking/mutex.c:909
[   41.576757] in_atomic(): 1, irqs_disabled(): 0, pid: 208, name: ptp4l
[   41.583212] INFO: lockdep is turned off.
[   41.587123] CPU: 1 PID: 208 Comm: ptp4l Not tainted 5.3.0-rc6-01445-ge950f2d4bc7f-dirty #1827
[   41.599873] [<c0313d7c>] (unwind_backtrace) from [<c030e13c>] (show_stack+0x10/0x14)
[   41.607584] [<c030e13c>] (show_stack) from [<c1212d50>] (dump_stack+0xd4/0x100)
[   41.614863] [<c1212d50>] (dump_stack) from [<c037dfc8>] (___might_sleep+0x1c8/0x2b4)
[   41.622574] [<c037dfc8>] (___might_sleep) from [<c122ea90>] (__mutex_lock+0x48/0xab8)
[   41.630368] [<c122ea90>] (__mutex_lock) from [<c122f51c>] (mutex_lock_nested+0x1c/0x24)
[   41.638340] [<c122f51c>] (mutex_lock_nested) from [<c0c6fe08>] (sja1105_static_config_reload+0x30/0x27c)
[   41.647779] [<c0c6fe08>] (sja1105_static_config_reload) from [<c0c7015c>] (sja1105_hwtstamp_set+0x108/0x1cc)
[   41.657562] [<c0c7015c>] (sja1105_hwtstamp_set) from [<c0feb650>] (dev_ifsioc+0x18c/0x330)
[   41.665788] [<c0feb650>] (dev_ifsioc) from [<c0febbd8>] (dev_ioctl+0x320/0x6e8)
[   41.673064] [<c0febbd8>] (dev_ioctl) from [<c0f8b1f4>] (sock_ioctl+0x334/0x5e8)
[   41.680340] [<c0f8b1f4>] (sock_ioctl) from [<c05404a8>] (do_vfs_ioctl+0xb0/0xa10)
[   41.687789] [<c05404a8>] (do_vfs_ioctl) from [<c0540e3c>] (ksys_ioctl+0x34/0x58)
[   41.695151] [<c0540e3c>] (ksys_ioctl) from [<c0301000>] (ret_fast_syscall+0x0/0x28)
[   41.702768] Exception stack(0xe8495fa8 to 0xe8495ff0)
[   41.707796] 5fa0:                   beff4a8c 00000001 00000011 000089b0 beff4a8c beff4a80
[   41.715933] 5fc0: beff4a8c 00000001 0000000c 00000036 b6fa98c8 004e19c1 00000001 00000000
[   41.724069] 5fe0: 004dcedc beff4a6c 004c0738 b6e7af4c
[   41.729860] BUG: scheduling while atomic: ptp4l/208/0x00000002
[   41.735682] INFO: lockdep is turned off.

Enabling RX timestamping will logically disturb the fastpath (processing
of meta frames). Replace bool hwts_rx_en with a bit that is checked
atomically from the fastpath and temporarily unset from the sleepable
context during a change of the RX timestamping process (a destructive
operation anyways, requires switch reset).
If found unset, the fastpath (net/dsa/tag_sja1105.c) will just drop any
received meta frame and not take the meta_lock at all.

Fixes: a602afd2 ("net: dsa: sja1105: Expose PTP timestamping ioctls to userspace")
Signed-off-by: NVladimir Oltean <olteanv@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      3e8db7e5
  15. 02 10月, 2019 2 次提交
    • J
      xen/efi: have a common runtime setup function · 09515706
      由 Juergen Gross 提交于 
      Today the EFI runtime functions are setup in architecture specific
code (x86 and arm), with the functions themselves living in drivers/xen
as they are not architecture dependent.

As the setup is exactly the same for arm and x86 move the setup to
drivers/xen, too. This at once removes the need to make the single
functions global visible.
Signed-off-by: NJuergen Gross <jgross@suse.com>
Reviewed-by: NJan Beulich <jbeulich@suse.com>
[boris: "Dropped EXPORT_SYMBOL_GPL(xen_efi_runtime_setup)"]
Signed-off-by: NBoris Ostrovsky <boris.ostrovsky@oracle.com>
      09515706
    • F
      netfilter: drop bridge nf reset from nf_reset · 895b5c9f
      由 Florian Westphal 提交于 
      commit 174e2381
("sk_buff: drop all skb extensions on free and skb scrubbing") made napi
recycle always drop skb extensions.  The additional skb_ext_del() that is
performed via nf_reset on napi skb recycle is not needed anymore.

Most nf_reset() calls in the stack are there so queued skb won't block
'rmmod nf_conntrack' indefinitely.

This removes the skb_ext_del from nf_reset, and renames it to a more
fitting nf_reset_ct().

In a few selected places, add a call to skb_ext_reset to make sure that
no active extensions remain.

I am submitting this for "net", because we're still early in the release
cycle.  The patch applies to net-next too, but I think the rename causes
needless divergence between those trees.
Suggested-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NFlorian Westphal <fw@strlen.de>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>
      895b5c9f
  17. 01 10月, 2019 4 次提交
  19. 29 9月, 2019 3 次提交
    • C
      mm, tracing: Print symbol name for call_site in trace events · f7d6316f
      由 Changbin Du 提交于 
      To improve the readability of raw slab trace points, print the call_site ip
using '%pS'. Then we can grep events with function names.

[002] ....   808.188897: kmem_cache_free: call_site=putname+0x47/0x50 ptr=00000000cef40c80
[002] ....   808.188898: kfree: call_site=security_cred_free+0x42/0x50 ptr=0000000062400820
[002] ....   808.188904: kmem_cache_free: call_site=put_cred_rcu+0x88/0xa0 ptr=0000000058d74ef8
[002] ....   808.188913: kmem_cache_alloc: call_site=prepare_creds+0x26/0x100 ptr=0000000058d74ef8 bytes_req=168 bytes_alloc=576 gfp_flags=GFP_KERNEL
[002] ....   808.188917: kmalloc: call_site=security_prepare_creds+0x77/0xa0 ptr=0000000062400820 bytes_req=8 bytes_alloc=336 gfp_flags=GFP_KERNEL|__GFP_ZERO
[002] ....   808.188920: kmem_cache_alloc: call_site=getname_flags+0x4f/0x1e0 ptr=00000000cef40c80 bytes_req=4096 bytes_alloc=4480 gfp_flags=GFP_KERNEL
[002] ....   808.188925: kmem_cache_free: call_site=putname+0x47/0x50 ptr=00000000cef40c80
[002] ....   808.188926: kfree: call_site=security_cred_free+0x42/0x50 ptr=0000000062400820
[002] ....   808.188931: kmem_cache_free: call_site=put_cred_rcu+0x88/0xa0 ptr=0000000058d74ef8

Link: http://lkml.kernel.org/r/20190914103215.23301-1-changbin.du@gmail.comSigned-off-by: NChangbin Du <changbin.du@gmail.com>
Signed-off-by: NSteven Rostedt (VMware) <rostedt@goodmis.org>
      f7d6316f
    • D
      Revert "Revert "Revert "mm, thp: consolidate THP gfp handling into alloc_hugepage_direct_gfpmask"" · 19deb769
      由 David Rientjes 提交于 
      This reverts commit 92717d42.

Since commit a8282608 ("Revert "mm, thp: restore node-local hugepage
allocations"") is reverted in this series, it is better to restore the
previous 5.2 behavior between the thp allocation and the page allocator
rather than to attempt any consolidation or cleanup for a policy that is
now reverted.  It's less risky during an rc cycle and subsequent patches
in this series further modify the same policy that the pre-5.3 behavior
implements.

Consolidation and cleanup can be done subsequent to a sane default page
allocation strategy, so this patch reverts a cleanup done on a strategy
that is now reverted and thus is the least risky option.
Signed-off-by: NDavid Rientjes <rientjes@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Stefan Priebe - Profihost AG <s.priebe@profihost.ag>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      19deb769
    • D
      Revert "Revert "mm, thp: restore node-local hugepage allocations"" · ac79f78d
      由 David Rientjes 提交于 
      This reverts commit a8282608.

The commit references the original intended semantic for MADV_HUGEPAGE
which has subsequently taken on three unique purposes:

 - enables or disables thp for a range of memory depending on the system's
   config (is thp "enabled" set to "always" or "madvise"),

 - determines the synchronous compaction behavior for thp allocations at
   fault (is thp "defrag" set to "always", "defer+madvise", or "madvise"),
   and

 - reverts a previous MADV_NOHUGEPAGE (there is no madvise mode to only
   clear previous hugepage advice).

These are the three purposes that currently exist in 5.2 and over the
past several years that userspace has been written around.  Adding a
NUMA locality preference adds a fourth dimension to an already conflated
advice mode.

Based on the semantic that MADV_HUGEPAGE has provided over the past
several years, there exist workloads that use the tunable based on these
principles: specifically that the allocation should attempt to
defragment a local node before falling back.  It is agreed that remote
hugepages typically (but not always) have a better access latency than
remote native pages, although on Naples this is at parity for
intersocket.

The revert commit that this patch reverts allows hugepage allocation to
immediately allocate remotely when local memory is fragmented.  This is
contrary to the semantic of MADV_HUGEPAGE over the past several years:
that is, memory compaction should be attempted locally before falling
back.

The performance degradation of remote hugepages over local hugepages on
Rome, for example, is 53.5% increased access latency.  For this reason,
the goal is to revert back to the 5.2 and previous behavior that would
attempt local defragmentation before falling back.  With the patch that
is reverted by this patch, we see performance degradations at the tail
because the allocator happily allocates the remote hugepage rather than
even attempting to make a local hugepage available.

zone_reclaim_mode is not a solution to this problem since it does not
only impact hugepage allocations but rather changes the memory
allocation strategy for *all* page allocations.
Signed-off-by: NDavid Rientjes <rientjes@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Stefan Priebe - Profihost AG <s.priebe@profihost.ag>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      ac79f78d
  21. 28 9月, 2019 2 次提交
    • F
      sk_buff: drop all skb extensions on free and skb scrubbing · 174e2381
      由 Florian Westphal 提交于 
      Now that we have a 3rd extension, add a new helper that drops the
extension space and use it when we need to scrub an sk_buff.

At this time, scrubbing clears secpath and bridge netfilter data, but
retains the tc skb extension, after this patch all three get cleared.

NAPI reuse/free assumes we can only have a secpath attached to skb, but
it seems better to clear all extensions there as well.

v2: add unlikely hint (Eric Dumazet)

Fixes: 95a7233c ("net: openvswitch: Set OvS recirc_id from tc chain index")
Signed-off-by: NFlorian Westphal <fw@strlen.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      174e2381
    • J
      ptp: correctly disable flags on old ioctls · 2df4de16
      由 Jacob Keller 提交于 
      Commit 41560658 ("PTP: introduce new versions of IOCTLs",
2019-09-13) introduced new versions of the PTP ioctls which actually
validate that the flags are acceptable values.

As part of this, it cleared the flags value using a bitwise
and+negation, in an attempt to prevent the old ioctl from accidentally
enabling new features.

This is incorrect for a couple of reasons. First, it results in
accidentally preventing previously working flags on the request ioctl.
By clearing the "valid" flags, we now no longer allow setting the
enable, rising edge, or falling edge flags.

Second, if we add new additional flags in the future, they must not be
set by the old ioctl. (Since the flag wasn't checked before, we could
potentially break userspace programs which sent garbage flag data.

The correct way to resolve this is to check for and clear all but the
originally valid flags.

Create defines indicating which flags are correctly checked and
interpreted by the original ioctls. Use these to clear any bits which
will not be correctly interpreted by the original ioctls.

In the future, new flags must be added to the VALID_FLAGS macros, but
*not* to the V1_VALID_FLAGS macros. In this way, new features may be
exposed over the v2 ioctls, but without breaking previous userspace
which happened to not clear the flags value properly. The old ioctl will
continue to behave the same way, while the new ioctl gains the benefit
of using the flags fields.

Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Felipe Balbi <felipe.balbi@linux.intel.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Christopher Hall <christopher.s.hall@intel.com>
Signed-off-by: NJacob Keller <jacob.e.keller@intel.com>
Acked-by: NRichard Cochran <richardcochran@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      2df4de16
  23. 27 9月, 2019 4 次提交
    • E
      tcp: honor SO_PRIORITY in TIME_WAIT state · f6c0f5d2
      由 Eric Dumazet 提交于 
      ctl packets sent on behalf of TIME_WAIT sockets currently
have a zero skb->priority, which can cause various problems.

In this patch we :

- add a tw_priority field in struct inet_timewait_sock.

- populate it from sk->sk_priority when a TIME_WAIT is created.

- For IPv4, change ip_send_unicast_reply() and its two
  callers to propagate tw_priority correctly.
  ip_send_unicast_reply() no longer changes sk->sk_priority.

- For IPv6, make sure TIME_WAIT sockets pass their tw_priority
  field to tcp_v6_send_response() and tcp_v6_send_ack().
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      f6c0f5d2
    • E
      ipv6: add priority parameter to ip6_xmit() · 4f6570d7
      由 Eric Dumazet 提交于 
      Currently, ip6_xmit() sets skb->priority based on sk->sk_priority

This is not desirable for TCP since TCP shares the same ctl socket
for a given netns. We want to be able to send RST or ACK packets
with a non zero skb->priority.

This patch has no functional change.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      4f6570d7
    • E
      sch_netem: fix rcu splat in netem_enqueue() · 159d2c7d
      由 Eric Dumazet 提交于 
      qdisc_root() use from netem_enqueue() triggers a lockdep warning.

__dev_queue_xmit() uses rcu_read_lock_bh() which is
not equivalent to rcu_read_lock() + local_bh_disable_bh as far
as lockdep is concerned.

WARNING: suspicious RCU usage
5.3.0-rc7+ #0 Not tainted
-----------------------------
include/net/sch_generic.h:492 suspicious rcu_dereference_check() usage!

other info that might help us debug this:

rcu_scheduler_active = 2, debug_locks = 1
3 locks held by syz-executor427/8855:
 #0: 00000000b5525c01 (rcu_read_lock_bh){....}, at: lwtunnel_xmit_redirect include/net/lwtunnel.h:92 [inline]
 #0: 00000000b5525c01 (rcu_read_lock_bh){....}, at: ip_finish_output2+0x2dc/0x2570 net/ipv4/ip_output.c:214
 #1: 00000000b5525c01 (rcu_read_lock_bh){....}, at: __dev_queue_xmit+0x20a/0x3650 net/core/dev.c:3804
 #2: 00000000364bae92 (&(&sch->q.lock)->rlock){+.-.}, at: spin_lock include/linux/spinlock.h:338 [inline]
 #2: 00000000364bae92 (&(&sch->q.lock)->rlock){+.-.}, at: __dev_xmit_skb net/core/dev.c:3502 [inline]
 #2: 00000000364bae92 (&(&sch->q.lock)->rlock){+.-.}, at: __dev_queue_xmit+0x14b8/0x3650 net/core/dev.c:3838

stack backtrace:
CPU: 0 PID: 8855 Comm: syz-executor427 Not tainted 5.3.0-rc7+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x172/0x1f0 lib/dump_stack.c:113
 lockdep_rcu_suspicious+0x153/0x15d kernel/locking/lockdep.c:5357
 qdisc_root include/net/sch_generic.h:492 [inline]
 netem_enqueue+0x1cfb/0x2d80 net/sched/sch_netem.c:479
 __dev_xmit_skb net/core/dev.c:3527 [inline]
 __dev_queue_xmit+0x15d2/0x3650 net/core/dev.c:3838
 dev_queue_xmit+0x18/0x20 net/core/dev.c:3902
 neigh_hh_output include/net/neighbour.h:500 [inline]
 neigh_output include/net/neighbour.h:509 [inline]
 ip_finish_output2+0x1726/0x2570 net/ipv4/ip_output.c:228
 __ip_finish_output net/ipv4/ip_output.c:308 [inline]
 __ip_finish_output+0x5fc/0xb90 net/ipv4/ip_output.c:290
 ip_finish_output+0x38/0x1f0 net/ipv4/ip_output.c:318
 NF_HOOK_COND include/linux/netfilter.h:294 [inline]
 ip_mc_output+0x292/0xf40 net/ipv4/ip_output.c:417
 dst_output include/net/dst.h:436 [inline]
 ip_local_out+0xbb/0x190 net/ipv4/ip_output.c:125
 ip_send_skb+0x42/0xf0 net/ipv4/ip_output.c:1555
 udp_send_skb.isra.0+0x6b2/0x1160 net/ipv4/udp.c:887
 udp_sendmsg+0x1e96/0x2820 net/ipv4/udp.c:1174
 inet_sendmsg+0x9e/0xe0 net/ipv4/af_inet.c:807
 sock_sendmsg_nosec net/socket.c:637 [inline]
 sock_sendmsg+0xd7/0x130 net/socket.c:657
 ___sys_sendmsg+0x3e2/0x920 net/socket.c:2311
 __sys_sendmmsg+0x1bf/0x4d0 net/socket.c:2413
 __do_sys_sendmmsg net/socket.c:2442 [inline]
 __se_sys_sendmmsg net/socket.c:2439 [inline]
 __x64_sys_sendmmsg+0x9d/0x100 net/socket.c:2439
 do_syscall_64+0xfd/0x6a0 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
Signed-off-by: NEric Dumazet <edumazet@google.com>
Reported-by: Nsyzbot <syzkaller@googlegroups.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      159d2c7d
    • M
      mm: treewide: clarify pgtable_page_{ctor,dtor}() naming · b4ed71f5
      由 Mark Rutland 提交于 
      The naming of pgtable_page_{ctor,dtor}() seems to have confused a few
people, and until recently arm64 used these erroneously/pointlessly for
other levels of page table.

To make it incredibly clear that these only apply to the PTE level, and to
align with the naming of pgtable_pmd_page_{ctor,dtor}(), let's rename them
to pgtable_pte_page_{ctor,dtor}().

These changes were generated with the following shell script:

----
git grep -lw 'pgtable_page_.tor' | while read FILE; do
    sed -i '{s/pgtable_page_ctor/pgtable_pte_page_ctor/}' $FILE;
    sed -i '{s/pgtable_page_dtor/pgtable_pte_page_dtor/}' $FILE;
done
----

... with the documentation re-flowed to remain under 80 columns, and
whitespace fixed up in macros to keep backslashes aligned.

There should be no functional change as a result of this patch.

Link: http://lkml.kernel.org/r/20190722141133.3116-1-mark.rutland@arm.comSigned-off-by: NMark Rutland <mark.rutland@arm.com>
Reviewed-by: NMike Rapoport <rppt@linux.ibm.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>	[m68k]
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      b4ed71f5
  25. 26 9月, 2019 12 次提交
    • M
      mm: introduce MADV_PAGEOUT · 1a4e58cc
      由 Minchan Kim 提交于 
      When a process expects no accesses to a certain memory range for a long
time, it could hint kernel that the pages can be reclaimed instantly but
data should be preserved for future use.  This could reduce workingset
eviction so it ends up increasing performance.

This patch introduces the new MADV_PAGEOUT hint to madvise(2) syscall.
MADV_PAGEOUT can be used by a process to mark a memory range as not
expected to be used for a long time so that kernel reclaims *any LRU*
pages instantly.  The hint can help kernel in deciding which pages to
evict proactively.

A note: It doesn't apply SWAP_CLUSTER_MAX LRU page isolation limit
intentionally because it's automatically bounded by PMD size.  If PMD
size(e.g., 256) makes some trouble, we could fix it later by limit it to
SWAP_CLUSTER_MAX[1].

- man-page material

MADV_PAGEOUT (since Linux x.x)

Do not expect access in the near future so pages in the specified
regions could be reclaimed instantly regardless of memory pressure.
Thus, access in the range after successful operation could cause
major page fault but never lose the up-to-date contents unlike
MADV_DONTNEED. Pages belonging to a shared mapping are only processed
if a write access is allowed for the calling process.

MADV_PAGEOUT cannot be applied to locked pages, Huge TLB pages, or
VM_PFNMAP pages.

[1] https://lore.kernel.org/lkml/20190710194719.GS29695@dhcp22.suse.cz/

[minchan@kernel.org: clear PG_active on MADV_PAGEOUT]
  Link: http://lkml.kernel.org/r/20190802200643.GA181880@google.com
[akpm@linux-foundation.org: resolve conflicts with hmm.git]
Link: http://lkml.kernel.org/r/20190726023435.214162-5-minchan@kernel.orgSigned-off-by: NMinchan Kim <minchan@kernel.org>
Reported-by: Nkbuild test robot <lkp@intel.com>
Acked-by: NMichal Hocko <mhocko@suse.com>
Cc: James E.J. Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Chris Zankel <chris@zankel.net>
Cc: Daniel Colascione <dancol@google.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Joel Fernandes (Google) <joel@joelfernandes.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Oleksandr Natalenko <oleksandr@redhat.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Sonny Rao <sonnyrao@google.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Tim Murray <timmurray@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      1a4e58cc
    • M
      mm: introduce MADV_COLD · 9c276cc6
      由 Minchan Kim 提交于 
      Patch series "Introduce MADV_COLD and MADV_PAGEOUT", v7.

- Background

The Android terminology used for forking a new process and starting an app
from scratch is a cold start, while resuming an existing app is a hot
start.  While we continually try to improve the performance of cold
starts, hot starts will always be significantly less power hungry as well
as faster so we are trying to make hot start more likely than cold start.

To increase hot start, Android userspace manages the order that apps
should be killed in a process called ActivityManagerService.
ActivityManagerService tracks every Android app or service that the user
could be interacting with at any time and translates that into a ranked
list for lmkd(low memory killer daemon).  They are likely to be killed by
lmkd if the system has to reclaim memory.  In that sense they are similar
to entries in any other cache.  Those apps are kept alive for
opportunistic performance improvements but those performance improvements
will vary based on the memory requirements of individual workloads.

- Problem

Naturally, cached apps were dominant consumers of memory on the system.
However, they were not significant consumers of swap even though they are
good candidate for swap.  Under investigation, swapping out only begins
once the low zone watermark is hit and kswapd wakes up, but the overall
allocation rate in the system might trip lmkd thresholds and cause a
cached process to be killed(we measured performance swapping out vs.
zapping the memory by killing a process.  Unsurprisingly, zapping is 10x
times faster even though we use zram which is much faster than real
storage) so kill from lmkd will often satisfy the high zone watermark,
resulting in very few pages actually being moved to swap.

- Approach

The approach we chose was to use a new interface to allow userspace to
proactively reclaim entire processes by leveraging platform information.
This allowed us to bypass the inaccuracy of the kernel’s LRUs for pages
that are known to be cold from userspace and to avoid races with lmkd by
reclaiming apps as soon as they entered the cached state.  Additionally,
it could provide many chances for platform to use much information to
optimize memory efficiency.

To achieve the goal, the patchset introduce two new options for madvise.
One is MADV_COLD which will deactivate activated pages and the other is
MADV_PAGEOUT which will reclaim private pages instantly.  These new
options complement MADV_DONTNEED and MADV_FREE by adding non-destructive
ways to gain some free memory space.  MADV_PAGEOUT is similar to
MADV_DONTNEED in a way that it hints the kernel that memory region is not
currently needed and should be reclaimed immediately; MADV_COLD is similar
to MADV_FREE in a way that it hints the kernel that memory region is not
currently needed and should be reclaimed when memory pressure rises.

This patch (of 5):

When a process expects no accesses to a certain memory range, it could
give a hint to kernel that the pages can be reclaimed when memory pressure
happens but data should be preserved for future use.  This could reduce
workingset eviction so it ends up increasing performance.

This patch introduces the new MADV_COLD hint to madvise(2) syscall.
MADV_COLD can be used by a process to mark a memory range as not expected
to be used in the near future.  The hint can help kernel in deciding which
pages to evict early during memory pressure.

It works for every LRU pages like MADV_[DONTNEED|FREE]. IOW, It moves

	active file page -> inactive file LRU
	active anon page -> inacdtive anon LRU

Unlike MADV_FREE, it doesn't move active anonymous pages to inactive file
LRU's head because MADV_COLD is a little bit different symantic.
MADV_FREE means it's okay to discard when the memory pressure because the
content of the page is *garbage* so freeing such pages is almost zero
overhead since we don't need to swap out and access afterward causes just
minor fault.  Thus, it would make sense to put those freeable pages in
inactive file LRU to compete other used-once pages.  It makes sense for
implmentaion point of view, too because it's not swapbacked memory any
longer until it would be re-dirtied.  Even, it could give a bonus to make
them be reclaimed on swapless system.  However, MADV_COLD doesn't mean
garbage so reclaiming them requires swap-out/in in the end so it's bigger
cost.  Since we have designed VM LRU aging based on cost-model, anonymous
cold pages would be better to position inactive anon's LRU list, not file
LRU.  Furthermore, it would help to avoid unnecessary scanning if system
doesn't have a swap device.  Let's start simpler way without adding
complexity at this moment.  However, keep in mind, too that it's a caveat
that workloads with a lot of pages cache are likely to ignore MADV_COLD on
anonymous memory because we rarely age anonymous LRU lists.

* man-page material

MADV_COLD (since Linux x.x)

Pages in the specified regions will be treated as less-recently-accessed
compared to pages in the system with similar access frequencies.  In
contrast to MADV_FREE, the contents of the region are preserved regardless
of subsequent writes to pages.

MADV_COLD cannot be applied to locked pages, Huge TLB pages, or VM_PFNMAP
pages.

[akpm@linux-foundation.org: resolve conflicts with hmm.git]
Link: http://lkml.kernel.org/r/20190726023435.214162-2-minchan@kernel.orgSigned-off-by: NMinchan Kim <minchan@kernel.org>
Reported-by: Nkbuild test robot <lkp@intel.com>
Acked-by: NMichal Hocko <mhocko@suse.com>
Acked-by: NJohannes Weiner <hannes@cmpxchg.org>
Cc: James E.J. Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Chris Zankel <chris@zankel.net>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Daniel Colascione <dancol@google.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Joel Fernandes (Google) <joel@joelfernandes.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Oleksandr Natalenko <oleksandr@redhat.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Sonny Rao <sonnyrao@google.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Tim Murray <timmurray@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      9c276cc6
    • K
      bug: move WARN_ON() "cut here" into exception handler · a44f71a9
      由 Kees Cook 提交于 
      The original clean up of "cut here" missed the WARN_ON() case (that does
not have a printk message), which was fixed recently by adding an explicit
printk of "cut here".  This had the downside of adding a printk() to every
WARN_ON() caller, which reduces the utility of using an instruction
exception to streamline the resulting code.  By making this a new BUGFLAG,
all of these can be removed and "cut here" can be handled by the exception
handler.

This was very pronounced on PowerPC, but the effect can be seen on x86 as
well.  The resulting text size of a defconfig build shows some small
savings from this patch:

   text    data     bss     dec     hex filename
19691167        5134320 1646664 26472151        193eed7 vmlinux.before
19676362        5134260 1663048 26473670        193f4c6 vmlinux.after

This change also opens the door for creating something like BUG_MSG(),
where a custom printk() before issuing BUG(), without confusing the "cut
here" line.

Link: http://lkml.kernel.org/r/201908200943.601DD59DCE@keescook
Fixes: 6b15f678 ("include/asm-generic/bug.h: fix "cut here" for WARN_ON for __WARN_TAINT architectures")
Signed-off-by: NKees Cook <keescook@chromium.org>
Reported-by: NChristophe Leroy <christophe.leroy@c-s.fr>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Drew Davenport <ddavenport@chromium.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
Cc: Feng Tang <feng.tang@intel.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      a44f71a9
    • K
      bug: consolidate __WARN_FLAGS usage · 2da1ead4
      由 Kees Cook 提交于 
      Instead of having separate tests for __WARN_FLAGS, merge the two #ifdef
blocks and replace the synonym WANT_WARN_ON_SLOWPATH macro.

Link: http://lkml.kernel.org/r/20190819234111.9019-7-keescook@chromium.orgSigned-off-by: NKees Cook <keescook@chromium.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Drew Davenport <ddavenport@chromium.org>
Cc: Feng Tang <feng.tang@intel.com>
Cc: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
Cc: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      2da1ead4
    • K
      bug: clean up helper macros to remove __WARN_TAINT() · d4bce140
      由 Kees Cook 提交于 
      In preparation for cleaning up "cut here" even more, this removes the
__WARN_*TAINT() helpers, as they limit the ability to add new BUGFLAG_*
flags to call sites.  They are removed by expanding them into full
__WARN_FLAGS() calls.

Link: http://lkml.kernel.org/r/20190819234111.9019-6-keescook@chromium.orgSigned-off-by: NKees Cook <keescook@chromium.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Drew Davenport <ddavenport@chromium.org>
Cc: Feng Tang <feng.tang@intel.com>
Cc: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
Cc: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      d4bce140
    • K
      bug: consolidate warn_slowpath_fmt() usage · f2f84b05
      由 Kees Cook 提交于 
      Instead of having a separate helper for no printk output, just consolidate
the logic into warn_slowpath_fmt().

Link: http://lkml.kernel.org/r/20190819234111.9019-4-keescook@chromium.orgSigned-off-by: NKees Cook <keescook@chromium.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Drew Davenport <ddavenport@chromium.org>
Cc: Feng Tang <feng.tang@intel.com>
Cc: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
Cc: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      f2f84b05
    • K
      bug: rename __WARN_printf_taint() to __WARN_printf() · 89348fc3
      由 Kees Cook 提交于 
      This just renames the helper to improve readability.

Link: http://lkml.kernel.org/r/20190819234111.9019-3-keescook@chromium.orgSigned-off-by: NKees Cook <keescook@chromium.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Drew Davenport <ddavenport@chromium.org>
Cc: Feng Tang <feng.tang@intel.com>
Cc: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
Cc: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      89348fc3
    • K
      bug: refactor away warn_slowpath_fmt_taint() · ee871133
      由 Kees Cook 提交于 
      Patch series "Clean up WARN() "cut here" handling", v2.

Christophe Leroy noticed that the fix for missing "cut here" in the WARN()
case was adding explicit printk() calls instead of teaching the exception
handler to add it.  This refactors the bug/warn infrastructure to pass
this information as a new BUGFLAG.

Longer details repeated from the last patch in the series:

bug: move WARN_ON() "cut here" into exception handler

The original cleanup of "cut here" missed the WARN_ON() case (that does
not have a printk message), which was fixed recently by adding an explicit
printk of "cut here".  This had the downside of adding a printk() to every
WARN_ON() caller, which reduces the utility of using an instruction
exception to streamline the resulting code.  By making this a new BUGFLAG,
all of these can be removed and "cut here" can be handled by the exception
handler.

This was very pronounced on PowerPC, but the effect can be seen on x86 as
well.  The resulting text size of a defconfig build shows some small
savings from this patch:

   text    data     bss     dec     hex filename
19691167        5134320 1646664 26472151        193eed7 vmlinux.before
19676362        5134260 1663048 26473670        193f4c6 vmlinux.after

This change also opens the door for creating something like BUG_MSG(),
where a custom printk() before issuing BUG(), without confusing the "cut
here" line.

This patch (of 7):

There's no reason to have specialized helpers for passing the warn taint
down to __warn().  Consolidate and refactor helper macros, removing
__WARN_printf() and warn_slowpath_fmt_taint().

Link: http://lkml.kernel.org/r/20190819234111.9019-2-keescook@chromium.orgSigned-off-by: NKees Cook <keescook@chromium.org>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Drew Davenport <ddavenport@chromium.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
Cc: Feng Tang <feng.tang@intel.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      ee871133
    • D
      kgdb: don't use a notifier to enter kgdb at panic; call directly · 7d92bda2
      由 Douglas Anderson 提交于 
      Right now kgdb/kdb hooks up to debug panics by registering for the panic
notifier.  This works OK except that it means that kgdb/kdb gets called
_after_ the CPUs in the system are taken offline.  That means that if
anything important was happening on those CPUs (like something that might
have contributed to the panic) you can't debug them.

Specifically I ran into a case where I got a panic because a task was
"blocked for more than 120 seconds" which was detected on CPU 2.  I nicely
got shown stack traces in the kernel log for all CPUs including CPU 0,
which was running 'PID: 111 Comm: kworker/0:1H' and was in the middle of
__mmc_switch().

I then ended up at the kdb prompt where switched over to kgdb to try to
look at local variables of the process on CPU 0.  I found that I couldn't.
Digging more, I found that I had no info on any tasks running on CPUs
other than CPU 2 and that asking kdb for help showed me "Error: no saved
data for this cpu".  This was because all the CPUs were offline.

Let's move the entry of kdb/kgdb to a direct call from panic() and stop
using the generic notifier.  Putting a direct call in allows us to order
things more properly and it also doesn't seem like we're breaking any
abstractions by calling into the debugger from the panic function.

Daniel said:

: This patch changes the way kdump and kgdb interact with each other.
: However it would seem rather odd to have both tools simultaneously armed
: and, even if they were, the user still has the option to use panic_timeout
: to force a kdump to happen.  Thus I think the change of order is
: acceptable.

Link: http://lkml.kernel.org/r/20190703170354.217312-1-dianders@chromium.orgSigned-off-by: NDouglas Anderson <dianders@chromium.org>
Reviewed-by: NDaniel Thompson <daniel.thompson@linaro.org>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Feng Tang <feng.tang@intel.com>
Cc: YueHaibing <yuehaibing@huawei.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Cc: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      7d92bda2
    • K
      uaccess: add missing __must_check attributes · 9dd819a1
      由 Kees Cook 提交于 
      The usercopy implementation comments describe that callers of the
copy_*_user() family of functions must always have their return values
checked.  This can be enforced at compile time with __must_check, so add
it where needed.

Link: http://lkml.kernel.org/r/201908251609.ADAD5CAAC1@keescookSigned-off-by: NKees Cook <keescook@chromium.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      9dd819a1
    • V
      kexec: restore arch_kexec_kernel_image_probe declaration · d5372c39
      由 Vasily Gorbik 提交于 
      arch_kexec_kernel_image_probe function declaration has been removed by
commit 9ec4ecef ("kexec_file,x86,powerpc: factor out kexec_file_ops
functions").  Still this function is overridden by couple of architectures
and proper prototype declaration is therefore important, so bring it back.
This fixes the following sparse warning on s390:
arch/s390/kernel/machine_kexec_file.c:333:5: warning: symbol
'arch_kexec_kernel_image_probe' was not declared.  Should it be static?

Link: http://lkml.kernel.org/r/patch.git-ff1c9045ebdc.your-ad-here.call-01564402297-ext-5690@work.hoursSigned-off-by: NVasily Gorbik <gor@linux.ibm.com>
Acked-by: NDave Young <dyoung@redhat.com>
Reviewed-by: NBhupesh Sharma <bhsharma@redhat.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: AKASHI Takahiro <takahiro.akashi@linaro.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      d5372c39
    • A
      cpumask: nicer for_each_cpumask_and() signature · 2a4a4082
      由 Alexey Dobriyan 提交于 
      Mask arguments can be swapped without changing anything.  Make arguments
names reflect that:

	#define for_each_cpu_and(cpu, mask1, mask2)

Link: http://lkml.kernel.org/r/20190724183350.GA15041@avx2Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      2a4a4082