Skip to content

K
Kernel

openeuler / Kernel
1 年多 前同步成功

通知 8
Star 0
Fork 0
K
Kernel
切换分支/标签
  1. 08 4月, 2020 4 次提交
    • P
      userfaultfd: wp: apply _PAGE_UFFD_WP bit · 292924b2
      由 Peter Xu 提交于 
      Firstly, introduce two new flags MM_CP_UFFD_WP[_RESOLVE] for
change_protection() when used with uffd-wp and make sure the two new flags
are exclusively used.  Then,

  - For MM_CP_UFFD_WP: apply the _PAGE_UFFD_WP bit and remove _PAGE_RW
    when a range of memory is write protected by uffd

  - For MM_CP_UFFD_WP_RESOLVE: remove the _PAGE_UFFD_WP bit and recover
    _PAGE_RW when write protection is resolved from userspace

And use this new interface in mwriteprotect_range() to replace the old
MM_CP_DIRTY_ACCT.

Do this change for both PTEs and huge PMDs.  Then we can start to identify
which PTE/PMD is write protected by general (e.g., COW or soft dirty
tracking), and which is for userfaultfd-wp.

Since we should keep the _PAGE_UFFD_WP when doing pte_modify(), add it
into _PAGE_CHG_MASK as well.  Meanwhile, since we have this new bit, we
can be even more strict when detecting uffd-wp page faults in either
do_wp_page() or wp_huge_pmd().

After we're with _PAGE_UFFD_WP, a special case is when a page is both
protected by the general COW logic and also userfault-wp.  Here the
userfault-wp will have higher priority and will be handled first.  Only
after the uffd-wp bit is cleared on the PTE/PMD will we continue to handle
the general COW.  These are the steps on what will happen with such a
page:

  1. CPU accesses write protected shared page (so both protected by
     general COW and uffd-wp), blocked by uffd-wp first because in
     do_wp_page we'll handle uffd-wp first, so it has higher priority
     than general COW.

  2. Uffd service thread receives the request, do UFFDIO_WRITEPROTECT
     to remove the uffd-wp bit upon the PTE/PMD.  However here we
     still keep the write bit cleared.  Notify the blocked CPU.

  3. The blocked CPU resumes the page fault process with a fault
     retry, during retry it'll notice it was not with the uffd-wp bit
     this time but it is still write protected by general COW, then
     it'll go though the COW path in the fault handler, copy the page,
     apply write bit where necessary, and retry again.

  4. The CPU will be able to access this page with write bit set.
Suggested-by: NAndrea Arcangeli <aarcange@redhat.com>
Signed-off-by: NPeter Xu <peterx@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Brian Geffon <bgeffon@google.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Martin Cracauer <cracauer@cons.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Bobby Powers <bobbypowers@gmail.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: "Kirill A . Shutemov" <kirill@shutemov.name>
Cc: Maya Gokhale <gokhale2@llnl.gov>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Marty McFadden <mcfadden8@llnl.gov>
Cc: Denis Plotnikov <dplotnikov@virtuozzo.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: "Dr . David Alan Gilbert" <dgilbert@redhat.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Shaohua Li <shli@fb.com>
Link: http://lkml.kernel.org/r/20200220163112.11409-8-peterx@redhat.comSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      292924b2
    • P
      mm: merge parameters for change_protection() · 58705444
      由 Peter Xu 提交于 
      change_protection() was used by either the NUMA or mprotect() code,
there's one parameter for each of the callers (dirty_accountable and
prot_numa).  Further, these parameters are passed along the calls:

  - change_protection_range()
  - change_p4d_range()
  - change_pud_range()
  - change_pmd_range()
  - ...

Now we introduce a flag for change_protect() and all these helpers to
replace these parameters.  Then we can avoid passing multiple parameters
multiple times along the way.

More importantly, it'll greatly simplify the work if we want to introduce
any new parameters to change_protection().  In the follow up patches, a
new parameter for userfaultfd write protection will be introduced.

No functional change at all.
Signed-off-by: NPeter Xu <peterx@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Reviewed-by: NJerome Glisse <jglisse@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Bobby Powers <bobbypowers@gmail.com>
Cc: Brian Geffon <bgeffon@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Denis Plotnikov <dplotnikov@virtuozzo.com>
Cc: "Dr . David Alan Gilbert" <dgilbert@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: "Kirill A . Shutemov" <kirill@shutemov.name>
Cc: Martin Cracauer <cracauer@cons.org>
Cc: Marty McFadden <mcfadden8@llnl.gov>
Cc: Maya Gokhale <gokhale2@llnl.gov>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Shaohua Li <shli@fb.com>
Link: http://lkml.kernel.org/r/20200220163112.11409-7-peterx@redhat.comSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      58705444
    • M
      mm: remove CONFIG_TRANSPARENT_HUGE_PAGECACHE · 396bcc52
      由 Matthew Wilcox (Oracle) 提交于 
      Commit e496cf3d ("thp: introduce CONFIG_TRANSPARENT_HUGE_PAGECACHE")
notes that it should be reverted when the PowerPC problem was fixed.  The
commit fixing the PowerPC problem (953c66c2) did not revert the
commit; instead setting CONFIG_TRANSPARENT_HUGE_PAGECACHE to the same as
CONFIG_TRANSPARENT_HUGEPAGE.  Checking with Kirill and Aneesh, this was an
oversight, so remove the Kconfig symbol and undo the work of commit
e496cf3d.
Signed-off-by: NMatthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Acked-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Link: http://lkml.kernel.org/r/20200318140253.6141-6-willy@infradead.orgSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      396bcc52
    • D
      mm, thp: track fallbacks due to failed memcg charges separately · 85b9f46e
      由 David Rientjes 提交于 
      The thp_fault_fallback and thp_file_fallback vmstats are incremented if
either the hugepage allocation fails through the page allocator or the
hugepage charge fails through mem cgroup.

This patch leaves this field untouched but adds two new fields,
thp_{fault,file}_fallback_charge, which is incremented only when the mem
cgroup charge fails.

This distinguishes between attempted hugepage allocations that fail due to
fragmentation (or low memory conditions) and those that fail due to mem
cgroup limits.  That can be used to determine the impact of fragmentation
on the system by excluding faults that failed due to memcg usage.
Signed-off-by: NDavid Rientjes <rientjes@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Reviewed-by: NYang Shi <yang.shi@linux.alibaba.com>
Acked-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Jeremy Cline <jcline@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Link: http://lkml.kernel.org/r/alpine.DEB.2.21.2003061422070.7412@chino.kir.corp.google.comSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      85b9f46e
  3. 03 4月, 2020 1 次提交
  5. 25 3月, 2020 2 次提交
    • T
      mm: Add vmf_insert_pfn_xxx_prot() for huge page-table entries · 9a9731b1
      由 Thomas Hellstrom (VMware) 提交于 
      For graphics drivers needing to modify the page-protection, add
huge page-table entries counterparts to vmf_insert_pfn_prot().

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: "Jérôme Glisse" <jglisse@redhat.com>
Cc: "Christian König" <christian.koenig@amd.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: NThomas Hellstrom (VMware) <thomas_os@shipmail.org>
Acked-by: NChristian König <christian.koenig@amd.com>
Acked-by: NAndrew Morton <akpm@linux-foundation.org>
      9a9731b1
    • T
      mm: Introduce vma_is_special_huge · 2484ca9b
      由 Thomas Hellstrom (VMware) 提交于 
      For VM_PFNMAP and VM_MIXEDMAP vmas that want to support transhuge pages
and -page table entries, introduce vma_is_special_huge() that takes the
same codepaths as vma_is_dax().

The use of "special" follows the definition in memory.c, vm_normal_page():
"Special" mappings do not wish to be associated with a "struct page"
(either it doesn't exist, or it exists but they don't want to touch it)

For PAGE_SIZE pages, "special" is determined per page table entry to be
able to deal with COW pages. But since we don't have huge COW pages,
we can classify a vma as either "special huge" or "normal huge".

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: "Jérôme Glisse" <jglisse@redhat.com>
Cc: "Christian König" <christian.koenig@amd.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: NThomas Hellstrom (VMware) <thomas_os@shipmail.org>
Acked-by: NChristian König <christian.koenig@amd.com>
Acked-by: NAndrew Morton <akpm@linux-foundation.org>
      2484ca9b
  7. 06 3月, 2020 1 次提交
  9. 01 2月, 2020 4 次提交
  11. 28 1月, 2020 1 次提交
  13. 14 1月, 2020 1 次提交
    • K
      mm/huge_memory.c: thp: fix conflict of above-47bit hint address and PMD alignment · 97d3d0f9
      由 Kirill A. Shutemov 提交于 
      Patch series "Fix two above-47bit hint address vs.  THP bugs".

The two get_unmapped_area() implementations have to be fixed to provide
THP-friendly mappings if above-47bit hint address is specified.

This patch (of 2):

Filesystems use thp_get_unmapped_area() to provide THP-friendly
mappings.  For DAX in particular.

Normally, the kernel doesn't create userspace mappings above 47-bit,
even if the machine allows this (such as with 5-level paging on x86-64).
Not all user space is ready to handle wide addresses.  It's known that
at least some JIT compilers use higher bits in pointers to encode their
information.

Userspace can ask for allocation from full address space by specifying
hint address (with or without MAP_FIXED) above 47-bits.  If the
application doesn't need a particular address, but wants to allocate
from whole address space it can specify -1 as a hint address.

Unfortunately, this trick breaks thp_get_unmapped_area(): the function
would not try to allocate PMD-aligned area if *any* hint address
specified.

Modify the routine to handle it correctly:

 - Try to allocate the space at the specified hint address with length
   padding required for PMD alignment.
 - If failed, retry without length padding (but with the same hint
   address);
 - If the returned address matches the hint address return it.
 - Otherwise, align the address as required for THP and return.

The user specified hint address is passed down to get_unmapped_area() so
above-47bit hint address will be taken into account without breaking
alignment requirements.

Link: http://lkml.kernel.org/r/20191220142548.7118-2-kirill.shutemov@linux.intel.com
Fixes: b569bab7 ("x86/mm: Prepare to expose larger address space to userspace")
Signed-off-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reported-by: NThomas Willhalm <thomas.willhalm@intel.com>
Tested-by: NDan Williams <dan.j.williams@intel.com>
Cc: "Aneesh Kumar K . V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: "Bruggeman, Otto G" <otto.g.bruggeman@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      97d3d0f9
  15. 02 12月, 2019 1 次提交
  17. 19 10月, 2019 1 次提交
  19. 29 9月, 2019 2 次提交
    • 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. 25 9月, 2019 3 次提交
  23. 25 8月, 2019 1 次提交
  25. 14 8月, 2019 2 次提交
    • A
      Revert "mm, thp: restore node-local hugepage allocations" · a8282608
      由 Andrea Arcangeli 提交于 
      This reverts commit 2f0799a0 ("mm, thp: restore node-local
hugepage allocations").

commit 2f0799a0 was rightfully applied to avoid the risk of a
severe regression that was reported by the kernel test robot at the end
of the merge window.  Now we understood the regression was a false
positive and was caused by a significant increase in fairness during a
swap trashing benchmark.  So it's safe to re-apply the fix and continue
improving the code from there.  The benchmark that reported the
regression is very useful, but it provides a meaningful result only when
there is no significant alteration in fairness during the workload.  The
removal of __GFP_THISNODE increased fairness.

__GFP_THISNODE cannot be used in the generic page faults path for new
memory allocations under the MPOL_DEFAULT mempolicy, or the allocation
behavior significantly deviates from what the MPOL_DEFAULT semantics are
supposed to be for THP and 4k allocations alike.

Setting THP defrag to "always" or using MADV_HUGEPAGE (with THP defrag
set to "madvise") has never meant to provide an implicit MPOL_BIND on
the "current" node the task is running on, causing swap storms and
providing a much more aggressive behavior than even zone_reclaim_node =
3.

Any workload who could have benefited from __GFP_THISNODE has now to
enable zone_reclaim_mode=1||2||3.  __GFP_THISNODE implicitly provided
the zone_reclaim_mode behavior, but it only did so if THP was enabled:
if THP was disabled, there would have been no chance to get any 4k page
from the current node if the current node was full of pagecache, which
further shows how this __GFP_THISNODE was misplaced in MADV_HUGEPAGE.
MADV_HUGEPAGE has never been intended to provide any zone_reclaim_mode
semantics, in fact the two are orthogonal, zone_reclaim_mode = 1|2|3
must work exactly the same with MADV_HUGEPAGE set or not.

The performance characteristic of memory depends on the hardware
details.  The numbers below are obtained on Naples/EPYC architecture and
the N/A projection extends them to show what we should aim for in the
future as a good THP NUMA locality default.  The benchmark used
exercises random memory seeks (note: the cost of the page faults is not
part of the measurement).

  D0 THP | D0 4k | D1 THP | D1 4k | D2 THP | D2 4k | D3 THP | D3 4k | ...
  0%     | +43%  | +45%   | +106% | +131%  | +224% | N/A    | N/A

D0 means distance zero (i.e.  local memory), D1 means distance one (i.e.
intra socket memory), D2 means distance two (i.e.  inter socket memory),
etc...

For the guest physical memory allocated by qemu and for guest mode
kernel the performance characteristic of RAM is more complex and an
ideal default could be:

  D0 THP | D1 THP | D0 4k | D2 THP | D1 4k | D3 THP | D2 4k | D3 4k | ...
  0%     | +58%   | +101% | N/A    | +222% | N/A    | N/A   | N/A

NOTE: the N/A are projections and haven't been measured yet, the
measurement in this case is done on a 1950x with only two NUMA nodes.
The THP case here means THP was used both in the host and in the guest.

After applying this commit the THP NUMA locality order that we'll get
out of MADV_HUGEPAGE is this:

  D0 THP | D1 THP | D2 THP | D3 THP | ... | D0 4k | D1 4k | D2 4k | D3 4k | ...

Before this commit it was:

  D0 THP | D0 4k | D1 4k | D2 4k | D3 4k | ...

Even if we ignore the breakage of large workloads that can't fit in a
single node that the __GFP_THISNODE implicit "current node" mbind
caused, the THP NUMA locality order provided by __GFP_THISNODE was still
not the one we shall aim for in the long term (i.e.  the first one at
the top).

After this commit is applied, we can introduce a new allocator multi
order API and to replace those two alloc_pages_vmas calls in the page
fault path, with a single multi order call:

        unsigned int order = (1 << HPAGE_PMD_ORDER) | (1 << 0);
        page = alloc_pages_multi_order(..., &order);
        if (!page)
        	goto out;
        if (!(order & (1 << 0))) {
        	VM_WARN_ON(order != 1 << HPAGE_PMD_ORDER);
        	/* THP fault */
        } else {
        	VM_WARN_ON(order != 1 << 0);
        	/* 4k fallback */
        }

The page allocator logic has to be altered so that when it fails on any
zone with order 9, it has to try again with a order 0 before falling
back to the next zone in the zonelist.

After that we need to do more measurements and evaluate if adding an
opt-in feature for guest mode is worth it, to swap "DN 4k | DN+1 THP"
with "DN+1 THP | DN 4k" at every NUMA distance crossing.

Link: http://lkml.kernel.org/r/20190503223146.2312-3-aarcange@redhat.comSigned-off-by: NAndrea Arcangeli <aarcange@redhat.com>
Acked-by: NMichal Hocko <mhocko@suse.com>
Acked-by: NMel Gorman <mgorman@suse.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: David Rientjes <rientjes@google.com>
Cc: Zi Yan <zi.yan@cs.rutgers.edu>
Cc: Stefan Priebe - Profihost AG <s.priebe@profihost.ag>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      a8282608
    • A
      Revert "Revert "mm, thp: consolidate THP gfp handling into alloc_hugepage_direct_gfpmask"" · 92717d42
      由 Andrea Arcangeli 提交于 
      Patch series "reapply: relax __GFP_THISNODE for MADV_HUGEPAGE mappings".

The fixes for what was originally reported as "pathological THP
behavior" we rightfully reverted to be sure not to introduced
regressions at end of a merge window after a severe regression report
from the kernel bot.  We can safely re-apply them now that we had time
to analyze the problem.

The mm process worked fine, because the good fixes were eventually
committed upstream without excessive delay.

The regression reported by the kernel bot however forced us to revert
the good fixes to be sure not to introduce regressions and to give us
the time to analyze the issue further.  The silver lining is that this
extra time allowed to think more at this issue and also plan for a
future direction to improve things further in terms of THP NUMA
locality.

This patch (of 2):

This reverts commit 356ff8a9 ("Revert "mm, thp: consolidate THP
gfp handling into alloc_hugepage_direct_gfpmask").  So it reapplies
89c83fb5 ("mm, thp: consolidate THP gfp handling into
alloc_hugepage_direct_gfpmask").

Consolidation of the THP allocation flags at the same place was meant to
be a clean up to easier handle otherwise scattered code which is
imposing a maintenance burden.  There were no real problems observed
with the gfp mask consolidation but the reversion was rushed through
without a larger consensus regardless.

This patch brings the consolidation back because this should make the
long term maintainability easier as well as it should allow future
changes to be less error prone.

[mhocko@kernel.org: changelog additions]
Link: http://lkml.kernel.org/r/20190503223146.2312-2-aarcange@redhat.comSigned-off-by: NAndrea Arcangeli <aarcange@redhat.com>
Acked-by: NMichal Hocko <mhocko@suse.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: David Rientjes <rientjes@google.com>
Cc: Zi Yan <zi.yan@cs.rutgers.edu>
Cc: Stefan Priebe - Profihost AG <s.priebe@profihost.ag>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      92717d42
  27. 19 7月, 2019 2 次提交
  29. 06 7月, 2019 1 次提交
    • L
      Revert "mm: page cache: store only head pages in i_pages" · 69bf4b6b
      由 Linus Torvalds 提交于 
      This reverts commit 5fd4ca2d.

Mikhail Gavrilov reports that it causes the VM_BUG_ON_PAGE() in
__delete_from_swap_cache() to trigger:

   page:ffffd6d34dff0000 refcount:1 mapcount:1 mapping:ffff97812323a689 index:0xfecec363
   anon
   flags: 0x17fffe00080034(uptodate|lru|active|swapbacked)
   raw: 0017fffe00080034 ffffd6d34c67c508 ffffd6d3504b8d48 ffff97812323a689
   raw: 00000000fecec363 0000000000000000 0000000100000000 ffff978433ace000
   page dumped because: VM_BUG_ON_PAGE(entry != page)
   page->mem_cgroup:ffff978433ace000
   ------------[ cut here ]------------
   kernel BUG at mm/swap_state.c:170!
   invalid opcode: 0000 [#1] SMP NOPTI
   CPU: 1 PID: 221 Comm: kswapd0 Not tainted 5.2.0-0.rc2.git0.1.fc31.x86_64 #1
   Hardware name: System manufacturer System Product Name/ROG STRIX X470-I GAMING, BIOS 2202 04/11/2019
   RIP: 0010:__delete_from_swap_cache+0x20d/0x240
   Code: 30 65 48 33 04 25 28 00 00 00 75 4a 48 83 c4 38 5b 5d 41 5c 41 5d 41 5e 41 5f c3 48 c7 c6 2f dc 0f 8a 48 89 c7 e8 93 1b fd ff <0f> 0b 48 c7 c6 a8 74 0f 8a e8 85 1b fd ff 0f 0b 48 c7 c6 a8 7d 0f
   RSP: 0018:ffffa982036e7980 EFLAGS: 00010046
   RAX: 0000000000000021 RBX: 0000000000000040 RCX: 0000000000000006
   RDX: 0000000000000000 RSI: 0000000000000086 RDI: ffff97843d657900
   RBP: 0000000000000001 R08: ffffa982036e7835 R09: 0000000000000535
   R10: ffff97845e21a46c R11: ffffa982036e7835 R12: ffff978426387120
   R13: 0000000000000000 R14: ffffd6d34dff0040 R15: ffffd6d34dff0000
   FS:  0000000000000000(0000) GS:ffff97843d640000(0000) knlGS:0000000000000000
   CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
   CR2: 00002cba88ef5000 CR3: 000000078a97c000 CR4: 00000000003406e0
   Call Trace:
    delete_from_swap_cache+0x46/0xa0
    try_to_free_swap+0xbc/0x110
    swap_writepage+0x13/0x70
    pageout.isra.0+0x13c/0x350
    shrink_page_list+0xc14/0xdf0
    shrink_inactive_list+0x1e5/0x3c0
    shrink_node_memcg+0x202/0x760
    shrink_node+0xe0/0x470
    balance_pgdat+0x2d1/0x510
    kswapd+0x220/0x420
    kthread+0xfb/0x130
    ret_from_fork+0x22/0x40

and it's not immediately obvious why it happens.  It's too late in the
rc cycle to do anything but revert for now.

Link: https://lore.kernel.org/lkml/CABXGCsN9mYmBD-4GaaeW_NrDu+FDXLzr_6x+XNxfmFV6QkYCDg@mail.gmail.com/Reported-and-bisected-by: NMikhail Gavrilov <mikhail.v.gavrilov@gmail.com>
Suggested-by: NJan Kara <jack@suse.cz>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Kirill Shutemov <kirill@shutemov.name>
Cc: William Kucharski <william.kucharski@oracle.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      69bf4b6b
  31. 19 6月, 2019 1 次提交
  33. 15 5月, 2019 5 次提交
  35. 06 4月, 2019 1 次提交
  37. 03 4月, 2019 1 次提交
  39. 06 3月, 2019 5 次提交