The quilt patch titled
Subject: alloc_tag: skip pgalloc_tag_swap if profiling is disabled
has been removed from the -mm tree. Its filename was
alloc_tag-skip-pgalloc_tag_swap-if-profiling-is-disabled.patch
This patch was dropped because it was merged into the mm-hotfixes-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
------------------------------------------------------
From: Suren Baghdasaryan <surenb@xxxxxxxxxx>
Subject: alloc_tag: skip pgalloc_tag_swap if profiling is disabled
Date: Thu, 26 Dec 2024 13:16:39 -0800
When memory allocation profiling is disabled, there is no need to swap
allocation tags during migration. Skip it to avoid unnecessary overhead.
Once I added these checks, the overhead of the mode when memory profiling
is enabled but turned off went down by about 50%.
Link: https://lkml.kernel.org/r/20241226211639.1357704-2-surenb@xxxxxxxxxx
Fixes: e0a955bf7f61 ("mm/codetag: add pgalloc_tag_copy()")
Signed-off-by: Suren Baghdasaryan <surenb@xxxxxxxxxx>
Cc: David Wang <00107082@xxxxxxx>
Cc: Kent Overstreet <kent.overstreet@xxxxxxxxx>
Cc: Yu Zhao <yuzhao@xxxxxxxxxx>
Cc: Zhenhua Huang <quic_zhenhuah@xxxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
lib/alloc_tag.c | 3 +++
1 file changed, 3 insertions(+)
--- a/lib/alloc_tag.c~alloc_tag-skip-pgalloc_tag_swap-if-profiling-is-disabled
+++ a/lib/alloc_tag.c
@@ -195,6 +195,9 @@ void pgalloc_tag_swap(struct folio *new,
union codetag_ref ref_old, ref_new;
struct alloc_tag *tag_old, *tag_new;
+ if (!mem_alloc_profiling_enabled())
+ return;
+
tag_old = pgalloc_tag_get(&old->page);
if (!tag_old)
return;
_
Patches currently in -mm which might be from surenb@xxxxxxxxxx are
alloc_tag-avoid-current-alloc_tag-manipulations-when-profiling-is-disabled.patch
