diff options
| author | David Hildenbrand <david@redhat.com> | 2024-08-20 15:22:10 +0300 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2024-09-04 07:15:38 +0300 |
| commit | ef5f379de302884b9b7ad9b62587a942a9f0bb55 (patch) | |
| tree | c82e5e3c80f9bafdbfe70dc6f89619dfd73d556b /include/linux/page-flags.h | |
| parent | 8c8685928910d0aae477dc7683037c3fcb3a904a (diff) | |
| download | linux-ef5f379de302884b9b7ad9b62587a942a9f0bb55.tar.xz | |
mm: always inline _compound_head() with CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP=y
We already force-inline page_fixed_fake_head(), page_is_fake_head() and
PageTail(), however the compiler might decide that _compound_head() is not
worthy to be inlined, because of page_fixed_fake_head().
The result is that, for example, PageAnonExclusive() now might involve a
function call when checking PageHuge(), which performs a
page_folio()->_compound_head() call. This can lead to a slight regression
of the stress-ng.clone benchmark.
This is not super-urgent to fix, but always inlining _compound_head()
seems like the obvious thing to do for this primitive, similar to the
other ones.
This change restores the slight regression and a compilation with
CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP=y shows no relevant bloat [2]:
add/remove: 15/14 grow/shrink: 79/87 up/down: 12836/-13917 (-1081)
...
Total: Before=32786363, After=32785282, chg -0.00%
[1] https://lkml.kernel.org/r/817150f2-abf7-430f-9973-540bd6cdd26f@intel.com
[2] https://lore.kernel.org/all/116e117c-2821-401d-8e62-b85cdec37f4a@redhat.com/
Link: https://lkml.kernel.org/r/20240820122210.660140-1-david@redhat.com
Fixes: c0bff412e67b ("mm: allow anon exclusive check over hugetlb tail pages")
Signed-off-by: David Hildenbrand <david@redhat.com>
Reported-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202407301049.5051dc19-oliver.sang@intel.com
Tested-by: Yin Fengwei <fengwei.yin@intel.com>
Cc: Peter Xu <peterx@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'include/linux/page-flags.h')
| -rw-r--r-- | include/linux/page-flags.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h index 17175a328e6b..2515ae85f191 100644 --- a/include/linux/page-flags.h +++ b/include/linux/page-flags.h @@ -232,7 +232,7 @@ static __always_inline int page_is_fake_head(const struct page *page) return page_fixed_fake_head(page) != page; } -static inline unsigned long _compound_head(const struct page *page) +static __always_inline unsigned long _compound_head(const struct page *page) { unsigned long head = READ_ONCE(page->compound_head); |