Re: [PATCH mm v4 07/39] mm: clarify __GFP_ZEROTAGS comment
From: Alexander Potapenko <glider@google.com>
Date: 2021-12-21 09:17:20
Also in:
linux-arm-kernel, lkml
On Mon, Dec 20, 2021 at 10:59 PM [off-list ref] wrote:
From: Andrey Konovalov <redacted>
Reviewed-by: Alexander Potapenko <glider@google.com>
__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.
Perhaps you could mention this intention explicitly in the comment? Right now it still doesn't reference performance.
quoted hunk ↗ jump to hunk
Clarify this intention of __GFP_ZEROTAGS in the comment. Signed-off-by: Andrey Konovalov <redacted> --- include/linux/gfp.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)diff --git a/include/linux/gfp.h b/include/linux/gfp.h index 0b2d2a636164..d6a184523ca2 100644 --- a/include/linux/gfp.h +++ b/include/linux/gfp.h@@ -228,8 +228,8 @@ 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). * * %__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 --2.25.1 -- You received this message because you are subscribed to the Google Groups "kasan-dev" group. To unsubscribe from this group and stop receiving emails from it, send an email to kasan-dev+unsubscribe@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/kasan-dev/92f3029f3647ab355450ed5c8252bad8cfae1e09.1640036051.git.andreyknvl%40google.com.
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