The patch titled
Subject: mm/page-owner: use gfp_nested_mask() instead of open coded masking
has been added to the -mm mm-unstable branch. Its filename is
mm-page-owner-use-gfp_nested_mask-instead-of-open-coded-masking.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-page-owner-use-gfp_nested_mask-instead-of-open-coded-masking.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Dave Chinner <david@xxxxxxxxxxxxx>
Subject: mm/page-owner: use gfp_nested_mask() instead of open coded masking
Date: Tue, 30 Apr 2024 15:28:25 +1000
The page-owner tracking code records stack traces during page allocation.
To do this, it must do a memory allocation for the stack information from
inside an existing memory allocation context. This internal allocation
must obey the high level caller allocation constraints to avoid generating
false positive warnings that have nothing to do with the code they are
instrumenting/tracking (e.g. through lockdep reclaim state tracking)
We also don't want recording stack traces to deplete emergency memory
reserves - debug code is useless if it creates new issues that can't be
replicated when the debug code is disabled.
Switch the stack tracking allocation masking to use gfp_nested_mask() to
address these issues. gfp_nested_mask() naturally strips GFP_ZONEMASK,
too, which greatly simplifies this code.
Link: https://lkml.kernel.org/r/20240430054604.4169568-4-david@xxxxxxxxxxxxx
Signed-off-by: Dave Chinner <dchinner@xxxxxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Reviewed-by: Vlastimil Babka <vbabka@xxxxxxx>
Reviewed-by: Oscar Salvador <osalvador@xxxxxxx>
Cc: Andrey Konovalov <andreyknvl@xxxxxxxxx>
Cc: Marco Elver <elver@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/page_owner.c | 7 +------
1 file changed, 1 insertion(+), 6 deletions(-)
--- a/mm/page_owner.c~mm-page-owner-use-gfp_nested_mask-instead-of-open-coded-masking
+++ a/mm/page_owner.c
@@ -168,13 +168,8 @@ static void add_stack_record_to_list(str
unsigned long flags;
struct stack *stack;
- /* Filter gfp_mask the same way stackdepot does, for consistency */
- gfp_mask &= ~GFP_ZONEMASK;
- gfp_mask &= (GFP_ATOMIC | GFP_KERNEL | __GFP_NOLOCKDEP);
- gfp_mask |= __GFP_NOWARN;
-
set_current_in_page_owner();
- stack = kmalloc(sizeof(*stack), gfp_mask);
+ stack = kmalloc(sizeof(*stack), gfp_nested_mask(gfp_mask));
if (!stack) {
unset_current_in_page_owner();
return;
_
Patches currently in -mm which might be from david@xxxxxxxxxxxxx are
mm-page-owner-use-gfp_nested_mask-instead-of-open-coded-masking.patch
