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| author | Andrey Konovalov <andreyknvl@google.com> | 2022-03-24 18:10:22 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2022-03-24 19:06:46 -0700 |
| commit | c82ce3195fd17e57a370e4dc8f36c195b8807b95 (patch) | |
| tree | 4c8adc66711116417c93826c7e5bcd3e3bcaa692 /include/linux/gfp.h | |
| parent | 487a32ec24be819e747af8c2ab0d5c515508086a (diff) | |
| download | linux-c82ce3195fd17e57a370e4dc8f36c195b8807b95.tar.gz linux-c82ce3195fd17e57a370e4dc8f36c195b8807b95.tar.bz2 linux-c82ce3195fd17e57a370e4dc8f36c195b8807b95.zip | |
mm: clarify __GFP_ZEROTAGS comment
__GFP_ZEROTAGS is intended as an optimization: if memory is zeroed during
allocation, it's possible to set memory tags at the same time with little
performance impact.
Clarify this intention of __GFP_ZEROTAGS in the comment.
Link: https://lkml.kernel.org/r/cdffde013973c5634a447513e10ec0d21e8eee29.1643047180.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Acked-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Collingbourne <pcc@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/gfp.h')
| -rw-r--r-- | include/linux/gfp.h | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/include/linux/gfp.h b/include/linux/gfp.h index 20f6fbe12993..72dc4ca75cf3 100644 --- a/include/linux/gfp.h +++ b/include/linux/gfp.h @@ -232,8 +232,10 @@ struct vm_area_struct; * * %__GFP_ZERO returns a zeroed page on success. * - * %__GFP_ZEROTAGS returns a page with zeroed memory tags on success, if - * __GFP_ZERO is set. + * %__GFP_ZEROTAGS zeroes memory tags at allocation time if the memory itself + * is being zeroed (either via __GFP_ZERO or via init_on_alloc). This flag is + * intended for optimization: setting memory tags at the same time as zeroing + * memory has minimal additional performace impact. * * %__GFP_SKIP_KASAN_POISON returns a page which does not need to be poisoned * on deallocation. Typically used for userspace pages. Currently only has an |