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> diff --git a/lib/alloc_tag.c b/lib/alloc_tag.c index 7dcebf118a3e..65e706e1bc19 100644 --- a/lib/alloc_tag.c +++ b/lib/alloc_tag.c @@ -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;
