Commit c82ce319 authored by Andrey Konovalov's avatar Andrey Konovalov Committed by Linus Torvalds

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.comSigned-off-by: default avatarAndrey Konovalov <andreyknvl@google.com>
Acked-by: default avatarMarco 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: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 487a32ec
...@@ -232,8 +232,10 @@ struct vm_area_struct; ...@@ -232,8 +232,10 @@ struct vm_area_struct;
* *
* %__GFP_ZERO returns a zeroed page on success. * %__GFP_ZERO returns a zeroed page on success.
* *
* %__GFP_ZEROTAGS returns a page with zeroed memory tags on success, if * %__GFP_ZEROTAGS zeroes memory tags at allocation time if the memory itself
* __GFP_ZERO is set. * 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 * %__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 * on deallocation. Typically used for userspace pages. Currently only has an
......
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