The patch titled
Subject: mm: avoid extra mem_alloc_profiling_enabled() checks
has been added to the -mm mm-unstable branch. Its filename is
mm-avoid-extra-mem_alloc_profiling_enabled-checks.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-avoid-extra-mem_alloc_profiling_enabled-checks.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: Suren Baghdasaryan <surenb@xxxxxxxxxx>
Subject: mm: avoid extra mem_alloc_profiling_enabled() checks
Date: Sat, 1 Feb 2025 15:18:00 -0800
Refactor code to avoid extra mem_alloc_profiling_enabled() checks inside
pgalloc_tag_get() function which is often called after that check was
already done.
Link: https://lkml.kernel.org/r/20250201231803.2661189-1-surenb@xxxxxxxxxx
Signed-off-by: Suren Baghdasaryan <surenb@xxxxxxxxxx>
Cc: David Wang <00107082@xxxxxxx>
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Cc: Kent Overstreet <kent.overstreet@xxxxxxxxx>
Cc: Minchan Kim <minchan@xxxxxxxxxx>
Cc: Pasha Tatashin <pasha.tatashin@xxxxxxxxxx>
Cc: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Cc: Shakeel Butt <shakeel.butt@xxxxxxxxx>
Cc: Sourav Panda <souravpanda@xxxxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Cc: Yu Zhao <yuzhao@xxxxxxxxxx>
Cc: Zhenhua Huang <quic_zhenhuah@xxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/pgalloc_tag.h | 33 ++++++++++++++++++---------------
lib/alloc_tag.c | 6 +++---
mm/page_alloc.c | 3 +--
3 files changed, 22 insertions(+), 20 deletions(-)
--- a/include/linux/pgalloc_tag.h~mm-avoid-extra-mem_alloc_profiling_enabled-checks
+++ a/include/linux/pgalloc_tag.h
@@ -205,28 +205,32 @@ static inline void pgalloc_tag_sub(struc
}
}
-static inline struct alloc_tag *pgalloc_tag_get(struct page *page)
+/* Should be called only if mem_alloc_profiling_enabled() */
+static inline struct alloc_tag *__pgalloc_tag_get(struct page *page)
{
struct alloc_tag *tag = NULL;
+ union pgtag_ref_handle handle;
+ union codetag_ref ref;
- if (mem_alloc_profiling_enabled()) {
- union pgtag_ref_handle handle;
- union codetag_ref ref;
-
- if (get_page_tag_ref(page, &ref, &handle)) {
- alloc_tag_sub_check(&ref);
- if (ref.ct)
- tag = ct_to_alloc_tag(ref.ct);
- put_page_tag_ref(handle);
- }
+ if (get_page_tag_ref(page, &ref, &handle)) {
+ alloc_tag_sub_check(&ref);
+ if (ref.ct)
+ tag = ct_to_alloc_tag(ref.ct);
+ put_page_tag_ref(handle);
}
return tag;
}
-static inline void pgalloc_tag_sub_pages(struct alloc_tag *tag, unsigned int nr)
+static inline void pgalloc_tag_sub_pages(struct page *page, unsigned int nr)
{
- if (mem_alloc_profiling_enabled() && tag)
+ struct alloc_tag *tag;
+
+ if (!mem_alloc_profiling_enabled())
+ return;
+
+ tag = __pgalloc_tag_get(page);
+ if (tag)
this_cpu_sub(tag->counters->bytes, PAGE_SIZE * nr);
}
@@ -241,8 +245,7 @@ static inline void clear_page_tag_ref(st
static inline void pgalloc_tag_add(struct page *page, struct task_struct *task,
unsigned int nr) {}
static inline void pgalloc_tag_sub(struct page *page, unsigned int nr) {}
-static inline struct alloc_tag *pgalloc_tag_get(struct page *page) { return NULL; }
-static inline void pgalloc_tag_sub_pages(struct alloc_tag *tag, unsigned int nr) {}
+static inline void pgalloc_tag_sub_pages(struct page *page, unsigned int nr) {}
static inline void alloc_tag_sec_init(void) {}
static inline void pgalloc_tag_split(struct folio *folio, int old_order, int new_order) {}
static inline void pgalloc_tag_swap(struct folio *new, struct folio *old) {}
--- a/lib/alloc_tag.c~mm-avoid-extra-mem_alloc_profiling_enabled-checks
+++ a/lib/alloc_tag.c
@@ -174,7 +174,7 @@ void pgalloc_tag_split(struct folio *fol
if (!mem_alloc_profiling_enabled())
return;
- tag = pgalloc_tag_get(&folio->page);
+ tag = __pgalloc_tag_get(&folio->page);
if (!tag)
return;
@@ -200,10 +200,10 @@ void pgalloc_tag_swap(struct folio *new,
if (!mem_alloc_profiling_enabled())
return;
- tag_old = pgalloc_tag_get(&old->page);
+ tag_old = __pgalloc_tag_get(&old->page);
if (!tag_old)
return;
- tag_new = pgalloc_tag_get(&new->page);
+ tag_new = __pgalloc_tag_get(&new->page);
if (!tag_new)
return;
--- a/mm/page_alloc.c~mm-avoid-extra-mem_alloc_profiling_enabled-checks
+++ a/mm/page_alloc.c
@@ -4832,12 +4832,11 @@ void __free_pages(struct page *page, uns
{
/* get PageHead before we drop reference */
int head = PageHead(page);
- struct alloc_tag *tag = pgalloc_tag_get(page);
if (put_page_testzero(page))
free_frozen_pages(page, order);
else if (!head) {
- pgalloc_tag_sub_pages(tag, (1 << order) - 1);
+ pgalloc_tag_sub_pages(page, (1 << order) - 1);
while (order-- > 0)
free_frozen_pages(page + (1 << order), order);
}
_
Patches currently in -mm which might be from surenb@xxxxxxxxxx are
mm-avoid-extra-mem_alloc_profiling_enabled-checks.patch
alloc_tag-uninline-code-gated-by-mem_alloc_profiling_key-in-slab-allocator.patch
alloc_tag-uninline-code-gated-by-mem_alloc_profiling_key-in-page-allocator.patch
