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| author | David Rientjes <rientjes@google.com> | 2020-04-07 06:04:28 +0300 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-04-07 20:43:38 +0300 |
| commit | 85b9f46e8ea451633ccd60a7d8cacbfff9f34047 (patch) | |
| tree | 500fe197ef3e38b19e5ff12311b091de9d8542df /Documentation | |
| parent | dcdf11ee144133328664d90836e712d840d047d9 (diff) | |
| download | linux-85b9f46e8ea451633ccd60a7d8cacbfff9f34047.tar.xz | |
mm, thp: track fallbacks due to failed memcg charges separately
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: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Yang Shi <yang.shi@linux.alibaba.com>
Acked-by: Kirill 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.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/admin-guide/mm/transhuge.rst | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/Documentation/admin-guide/mm/transhuge.rst b/Documentation/admin-guide/mm/transhuge.rst index f79ebbcd6725..2f31de8f7c74 100644 --- a/Documentation/admin-guide/mm/transhuge.rst +++ b/Documentation/admin-guide/mm/transhuge.rst @@ -310,6 +310,11 @@ thp_fault_fallback is incremented if a page fault fails to allocate a huge page and instead falls back to using small pages. +thp_fault_fallback_charge + is incremented if a page fault fails to charge a huge page and + instead falls back to using small pages even though the + allocation was successful. + thp_collapse_alloc_failed is incremented if khugepaged found a range of pages that should be collapsed into one huge page but failed @@ -323,6 +328,11 @@ thp_file_fallback is incremented if a file huge page is attempted to be allocated but fails and instead falls back to using small pages. +thp_file_fallback_charge + is incremented if a file huge page cannot be charged and instead + falls back to using small pages even though the allocation was + successful. + thp_file_mapped is incremented every time a file huge page is mapped into user address space. |