diff options
| author | Andrey Konovalov <[email protected]> | 2022-03-24 18:10:22 -0700 |
|---|---|---|
| committer | Linus Torvalds <[email protected]> | 2022-03-24 19:06:46 -0700 |
| commit | c82ce3195fd17e57a370e4dc8f36c195b8807b95 (patch) | |
| tree | 4c8adc66711116417c93826c7e5bcd3e3bcaa692 | |
| parent | 487a32ec24be819e747af8c2ab0d5c515508086a (diff) | |
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 <[email protected]>
Acked-by: Marco Elver <[email protected]>
Cc: Alexander Potapenko <[email protected]>
Cc: Andrey Ryabinin <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Cc: Evgenii Stepanov <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Peter Collingbourne <[email protected]>
Cc: Vincenzo Frascino <[email protected]>
Cc: Will Deacon <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
| -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 |