[PATCH mm v5 07/39] mm: clarify __GFP_ZEROTAGS comment
From: <hidden>
Date: 2021-12-30 19:13:06
Also in:
linux-arm-kernel, lkml
Subsystem:
memory management - core, memory management - page allocator, the rest · Maintainers:
Andrew Morton, David Hildenbrand, Vlastimil Babka, Linus Torvalds
From: Andrey Konovalov <redacted> __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. Signed-off-by: Andrey Konovalov <redacted> --- Changes v4->v5: - Mention optimization intention in the comment. --- include/linux/gfp.h | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/include/linux/gfp.h b/include/linux/gfp.h
index 5f893d994dcd..19e55f3fdd04 100644
--- a/include/linux/gfp.h
+++ b/include/linux/gfp.h@@ -228,8 +228,10 @@ 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
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2.25.1