The patch titled
Subject: alloc_tag: introduce pgtag_ref_handle to abstract page tag references
has been added to the -mm mm-unstable branch. Its filename is
alloc_tag-introduce-pgtag_ref_handle-to-abstract-page-tag-references.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/alloc_tag-introduce-pgtag_ref_handle-to-abstract-page-tag-references.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: alloc_tag: introduce pgtag_ref_handle to abstract page tag references
Date: Wed, 23 Oct 2024 10:07:58 -0700
To simplify later changes to page tag references, introduce new
pgtag_ref_handle type. This allows easy replacement of page_ext as a
storage of page allocation tags.
Link: https://lkml.kernel.org/r/20241023170759.999909-6-surenb@xxxxxxxxxx
Signed-off-by: Suren Baghdasaryan <surenb@xxxxxxxxxx>
Reviewed-by: Pasha Tatashin <pasha.tatashin@xxxxxxxxxx>
Cc: Ard Biesheuvel <ardb@xxxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Cc: Borislav Petkov (AMD) <bp@xxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxxxxxxxxx>
Cc: Daniel Gomez <da.gomez@xxxxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: Davidlohr Bueso <dave@xxxxxxxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Cc: Dennis Zhou <dennis@xxxxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: John Hubbard <jhubbard@xxxxxxxxxx>
Cc: Jonathan Corbet <corbet@xxxxxxx>
Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
Cc: Kalesh Singh <kaleshsingh@xxxxxxxxxx>
Cc: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: Kent Overstreet <kent.overstreet@xxxxxxxxx>
Cc: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx>
Cc: Luis Chamberlain <mcgrof@xxxxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: Mike Rapoport (Microsoft) <rppt@xxxxxxxxxx>
Cc: Minchan Kim <minchan@xxxxxxxxxx>
Cc: Paul E. McKenney <paulmck@xxxxxxxxxx>
Cc: Petr Pavlu <petr.pavlu@xxxxxxxx>
Cc: Roman Gushchin <roman.gushchin@xxxxxxxxx>
Cc: Sami Tolvanen <samitolvanen@xxxxxxxxxx>
Cc: Sourav Panda <souravpanda@xxxxxxxxxx>
Cc: Steven Rostedt (Google) <rostedt@xxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Thomas Huth <thuth@xxxxxxxxxx>
Cc: Uladzislau Rezki (Sony) <urezki@xxxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Cc: Xiongwei Song <xiongwei.song@xxxxxxxxxxxxx>
Cc: Yu Zhao <yuzhao@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/mm.h | 25 ++++-----
include/linux/pgalloc_tag.h | 90 ++++++++++++++++++++--------------
2 files changed, 66 insertions(+), 49 deletions(-)
--- a/include/linux/mm.h~alloc_tag-introduce-pgtag_ref_handle-to-abstract-page-tag-references
+++ a/include/linux/mm.h
@@ -4180,37 +4180,38 @@ static inline void pgalloc_tag_split(str
return;
for (i = nr_pages; i < (1 << old_order); i += nr_pages) {
- union codetag_ref *ref = get_page_tag_ref(folio_page(folio, i));
+ union pgtag_ref_handle handle;
+ union codetag_ref ref;
- if (ref) {
+ if (get_page_tag_ref(folio_page(folio, i), &ref, &handle)) {
/* Set new reference to point to the original tag */
- alloc_tag_ref_set(ref, tag);
- put_page_tag_ref(ref);
+ alloc_tag_ref_set(&ref, tag);
+ update_page_tag_ref(handle, &ref);
+ put_page_tag_ref(handle);
}
}
}
static inline void pgalloc_tag_copy(struct folio *new, struct folio *old)
{
+ union pgtag_ref_handle handle;
+ union codetag_ref ref;
struct alloc_tag *tag;
- union codetag_ref *ref;
tag = pgalloc_tag_get(&old->page);
if (!tag)
return;
- ref = get_page_tag_ref(&new->page);
- if (!ref)
+ if (!get_page_tag_ref(&new->page, &ref, &handle))
return;
/* Clear the old ref to the original allocation tag. */
clear_page_tag_ref(&old->page);
/* Decrement the counters of the tag on get_new_folio. */
- alloc_tag_sub(ref, folio_size(new));
-
- __alloc_tag_ref_set(ref, tag);
-
- put_page_tag_ref(ref);
+ alloc_tag_sub(&ref, folio_size(new));
+ __alloc_tag_ref_set(&ref, tag);
+ update_page_tag_ref(handle, &ref);
+ put_page_tag_ref(handle);
}
#else /* !CONFIG_MEM_ALLOC_PROFILING */
static inline void pgalloc_tag_split(struct folio *folio, int old_order, int new_order)
--- a/include/linux/pgalloc_tag.h~alloc_tag-introduce-pgtag_ref_handle-to-abstract-page-tag-references
+++ a/include/linux/pgalloc_tag.h
@@ -11,46 +11,59 @@
#include <linux/page_ext.h>
+union pgtag_ref_handle {
+ union codetag_ref *ref; /* reference in page extension */
+};
+
extern struct page_ext_operations page_alloc_tagging_ops;
-static inline union codetag_ref *codetag_ref_from_page_ext(struct page_ext *page_ext)
+/* Should be called only if mem_alloc_profiling_enabled() */
+static inline bool get_page_tag_ref(struct page *page, union codetag_ref *ref,
+ union pgtag_ref_handle *handle)
{
- return (union codetag_ref *)page_ext_data(page_ext, &page_alloc_tagging_ops);
-}
+ struct page_ext *page_ext;
+ union codetag_ref *tmp;
-static inline struct page_ext *page_ext_from_codetag_ref(union codetag_ref *ref)
-{
- return (void *)ref - page_alloc_tagging_ops.offset;
+ if (!page)
+ return false;
+
+ page_ext = page_ext_get(page);
+ if (!page_ext)
+ return false;
+
+ tmp = (union codetag_ref *)page_ext_data(page_ext, &page_alloc_tagging_ops);
+ ref->ct = tmp->ct;
+ handle->ref = tmp;
+ return true;
}
-/* Should be called only if mem_alloc_profiling_enabled() */
-static inline union codetag_ref *get_page_tag_ref(struct page *page)
+static inline void put_page_tag_ref(union pgtag_ref_handle handle)
{
- if (page) {
- struct page_ext *page_ext = page_ext_get(page);
+ if (WARN_ON(!handle.ref))
+ return;
- if (page_ext)
- return codetag_ref_from_page_ext(page_ext);
- }
- return NULL;
+ page_ext_put((void *)handle.ref - page_alloc_tagging_ops.offset);
}
-static inline void put_page_tag_ref(union codetag_ref *ref)
+static inline void update_page_tag_ref(union pgtag_ref_handle handle,
+ union codetag_ref *ref)
{
- if (WARN_ON(!ref))
+ if (WARN_ON(!handle.ref || !ref))
return;
- page_ext_put(page_ext_from_codetag_ref(ref));
+ handle.ref->ct = ref->ct;
}
static inline void clear_page_tag_ref(struct page *page)
{
if (mem_alloc_profiling_enabled()) {
- union codetag_ref *ref = get_page_tag_ref(page);
+ union pgtag_ref_handle handle;
+ union codetag_ref ref;
- if (ref) {
- set_codetag_empty(ref);
- put_page_tag_ref(ref);
+ if (get_page_tag_ref(page, &ref, &handle)) {
+ set_codetag_empty(&ref);
+ update_page_tag_ref(handle, &ref);
+ put_page_tag_ref(handle);
}
}
}
@@ -59,11 +72,13 @@ static inline void pgalloc_tag_add(struc
unsigned int nr)
{
if (mem_alloc_profiling_enabled()) {
- union codetag_ref *ref = get_page_tag_ref(page);
+ union pgtag_ref_handle handle;
+ union codetag_ref ref;
- if (ref) {
- alloc_tag_add(ref, task->alloc_tag, PAGE_SIZE * nr);
- put_page_tag_ref(ref);
+ if (get_page_tag_ref(page, &ref, &handle)) {
+ alloc_tag_add(&ref, task->alloc_tag, PAGE_SIZE * nr);
+ update_page_tag_ref(handle, &ref);
+ put_page_tag_ref(handle);
}
}
}
@@ -71,11 +86,13 @@ static inline void pgalloc_tag_add(struc
static inline void pgalloc_tag_sub(struct page *page, unsigned int nr)
{
if (mem_alloc_profiling_enabled()) {
- union codetag_ref *ref = get_page_tag_ref(page);
+ union pgtag_ref_handle handle;
+ union codetag_ref ref;
- if (ref) {
- alloc_tag_sub(ref, PAGE_SIZE * nr);
- put_page_tag_ref(ref);
+ if (get_page_tag_ref(page, &ref, &handle)) {
+ alloc_tag_sub(&ref, PAGE_SIZE * nr);
+ update_page_tag_ref(handle, &ref);
+ put_page_tag_ref(handle);
}
}
}
@@ -85,13 +102,14 @@ static inline struct alloc_tag *pgalloc_
struct alloc_tag *tag = NULL;
if (mem_alloc_profiling_enabled()) {
- union codetag_ref *ref = get_page_tag_ref(page);
+ union pgtag_ref_handle handle;
+ union codetag_ref ref;
- alloc_tag_sub_check(ref);
- if (ref) {
- if (ref->ct)
- tag = ct_to_alloc_tag(ref->ct);
- put_page_tag_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);
}
}
@@ -106,8 +124,6 @@ static inline void pgalloc_tag_sub_pages
#else /* CONFIG_MEM_ALLOC_PROFILING */
-static inline union codetag_ref *get_page_tag_ref(struct page *page) { return NULL; }
-static inline void put_page_tag_ref(union codetag_ref *ref) {}
static inline void clear_page_tag_ref(struct page *page) {}
static inline void pgalloc_tag_add(struct page *page, struct task_struct *task,
unsigned int nr) {}
_
Patches currently in -mm which might be from surenb@xxxxxxxxxx are
maple_tree-add-mas_for_each_rev-helper.patch
alloc_tag-introduce-shutdown_mem_profiling-helper-function.patch
alloc_tag-load-module-tags-into-separate-contiguous-memory.patch
alloc_tag-populate-memory-for-module-tags-as-needed.patch
alloc_tag-introduce-pgtag_ref_handle-to-abstract-page-tag-references.patch
alloc_tag-support-for-page-allocation-tag-compression.patch
