Commit b7d1fdc0 authored by Barry Song's avatar Barry Song Committed by Kefeng Wang
Browse files

mm: correct the docs for thp_fault_alloc and thp_fault_fallback 

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category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I9Q9DF
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=a14421ae2a99378c4103bb03606465ab13e75509

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The documentation does not align with the code.  In
__do_huge_pmd_anonymous_page(), THP_FAULT_FALLBACK is incremented when
mem_cgroup_charge() fails, despite the allocation succeeding, whereas
THP_FAULT_ALLOC is only incremented after a successful charge.

Link: https://lkml.kernel.org/r/20240412114858.407208-5-21cnbao@gmail.com


Signed-off-by: default avatarBarry Song <v-songbaohua@oppo.com>
Reviewed-by: default avatarRyan Roberts <ryan.roberts@arm.com>
Reviewed-by: default avatarDavid Hildenbrand <david@redhat.com>
Cc: Chris Li <chrisl@kernel.org>
Cc: Domenico Cerasuolo <cerasuolodomenico@gmail.com>
Cc: Kairui Song <kasong@tencent.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Peter Xu <peterx@redhat.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Yosry Ahmed <yosryahmed@google.com>
Cc: Yu Zhao <yuzhao@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent e7b1e851

Documentation/admin-guide/mm/transhuge.rst

+2 −2
Original line number Diff line number Diff line
@@ -396,7 +396,7 @@ monitor how successfully the system is providing huge pages for use. 


thp_fault_alloc

	is incremented every time a huge page is successfully

	allocated to handle a page fault.

	allocated and charged to handle a page fault.



thp_collapse_alloc

	is incremented by khugepaged when it has found
@@ -404,7 +404,7 @@ thp_collapse_alloc 
	successfully allocated a new huge page to store the data.



thp_fault_fallback

	is incremented if a page fault fails to allocate

	is incremented if a page fault fails to allocate or charge

	a huge page and instead falls back to using small pages.



thp_fault_fallback_charge