UPSTREAM: alloc_tag: skip pgalloc_tag_swap if profiling is disabled

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@google.com
Fixes: e0a955bf7f ("mm/codetag: add pgalloc_tag_copy()")
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Cc: David Wang <00107082@163.com>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Yu Zhao <yuzhao@google.com>
Cc: Zhenhua Huang <quic_zhenhuah@quicinc.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

(cherry picked from commit 05c82ee363f64c64b87a0cfd744298e9333475f5)
Bug: 380948583
Change-Id: I38c32cac6b965cf9658e3b3f738033a71d625691
Signed-off-by: Suren Baghdasaryan <surenb@google.com>

This commit is contained in:

Suren Baghdasaryan

2024-12-26 13:16:39 -08:00

parent 250da94778

commit 65a83238b1

1 changed files with 3 additions and 0 deletions

									
										lib/alloc_tag.c
									
		+3
		
												View File
												
				@@ -195,6 +195,9 @@ void pgalloc_tag_swap(struct folio *new, struct folio *old)

					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;