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lib: introduce support for page allocation tagging

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Introduce helper functions to easily instrument page allocators by storing
a pointer to the allocation tag associated with the code that allocated
the page in a page_ext field.

Link: https://lkml.kernel.org/r/20240321163705.3067592-15-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Co-developed-by: Kent Overstreet <kent.overstreet@linux.dev>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Tested-by: Kees Cook <keescook@chromium.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Alex Gaynor <alex.gaynor@gmail.com>
Cc: Alice Ryhl <aliceryhl@google.com>
Cc: Andreas Hindborg <a.hindborg@samsung.com>
Cc: Benno Lossin <benno.lossin@proton.me>
Cc: "Björn Roy Baron" <bjorn3_gh@protonmail.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Gary Guo <gary@garyguo.net>
Cc: Miguel Ojeda <ojeda@kernel.org>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Wedson Almeida Filho <wedsonaf@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Suren Baghdasaryan 2024-03-21 09:36:36 -07:00 committed by Andrew Morton
parent 22d407b164
commit dcfe378c81
7 changed files with 105 additions and 1 deletions
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1
include/linux/page_ext.h
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@ -4,7 +4,6 @@
#include <linux/types.h>
#include <linux/stacktrace.h>
#include <linux/stackdepot.h>
struct pglist_data;

78
include/linux/pgalloc_tag.h Normal file
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@ -0,0 +1,78 @@
/* SPDX-License-Identifier: GPL-2.0 */
/*
* page allocation tagging
*/
#ifndef _LINUX_PGALLOC_TAG_H
#define _LINUX_PGALLOC_TAG_H
#include <linux/alloc_tag.h>
#ifdef CONFIG_MEM_ALLOC_PROFILING
#include <linux/page_ext.h>
extern struct page_ext_operations page_alloc_tagging_ops;
extern struct page_ext *page_ext_get(struct page *page);
extern void page_ext_put(struct page_ext *page_ext);
static inline union codetag_ref *codetag_ref_from_page_ext(struct page_ext *page_ext)
{
return (void *)page_ext + page_alloc_tagging_ops.offset;
}
static inline struct page_ext *page_ext_from_codetag_ref(union codetag_ref *ref)
{
return (void *)ref - page_alloc_tagging_ops.offset;
}
/* Should be called only if mem_alloc_profiling_enabled() */
static inline union codetag_ref *get_page_tag_ref(struct page *page)
{
if (page) {
struct page_ext *page_ext = page_ext_get(page);
if (page_ext)
return codetag_ref_from_page_ext(page_ext);
}
return NULL;
}
static inline void put_page_tag_ref(union codetag_ref *ref)
{
page_ext_put(page_ext_from_codetag_ref(ref));
}
static inline void pgalloc_tag_add(struct page *page, struct task_struct *task,
unsigned int nr)
{
if (mem_alloc_profiling_enabled()) {
union codetag_ref *ref = get_page_tag_ref(page);
if (ref) {
alloc_tag_add(ref, task->alloc_tag, PAGE_SIZE * nr);
put_page_tag_ref(ref);
}
}
}
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);
if (ref) {
alloc_tag_sub(ref, PAGE_SIZE * nr);
put_page_tag_ref(ref);
}
}
}
#else /* CONFIG_MEM_ALLOC_PROFILING */
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) {}
#endif /* CONFIG_MEM_ALLOC_PROFILING */
#endif /* _LINUX_PGALLOC_TAG_H */

1
lib/Kconfig.debug
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@ -978,6 +978,7 @@ config MEM_ALLOC_PROFILING
depends on PROC_FS
depends on !DEBUG_FORCE_WEAK_PER_CPU
select CODE_TAGGING
select PAGE_EXTENSION
help
Track allocation source code and record total allocation size
initiated at that code location. The mechanism can be used to track

17
lib/alloc_tag.c
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@ -3,6 +3,7 @@
#include <linux/fs.h>
#include <linux/gfp.h>
#include <linux/module.h>
#include <linux/page_ext.h>
#include <linux/proc_fs.h>
#include <linux/seq_buf.h>
#include <linux/seq_file.h>
@ -118,6 +119,22 @@ static bool alloc_tag_module_unload(struct codetag_type *cttype,
return module_unused;
}
static __init bool need_page_alloc_tagging(void)
{
return true;
}
static __init void init_page_alloc_tagging(void)
{
}
struct page_ext_operations page_alloc_tagging_ops = {
.size = sizeof(union codetag_ref),
.need = need_page_alloc_tagging,
.init = init_page_alloc_tagging,
};
EXPORT_SYMBOL(page_alloc_tagging_ops);
static struct ctl_table memory_allocation_profiling_sysctls[] = {
{
.procname = "mem_profiling",

1
mm/mm_init.c
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@ -24,6 +24,7 @@
#include <linux/page_ext.h>
#include <linux/pti.h>
#include <linux/pgtable.h>
#include <linux/stackdepot.h>
#include <linux/swap.h>
#include <linux/cma.h>
#include <linux/crash_dump.h>

4
mm/page_alloc.c
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@ -54,6 +54,7 @@
#include <linux/khugepaged.h>
#include <linux/delayacct.h>
#include <linux/cacheinfo.h>
#include <linux/pgalloc_tag.h>
#include <asm/div64.h>
#include "internal.h"
#include "shuffle.h"
@ -1101,6 +1102,7 @@ __always_inline bool free_pages_prepare(struct page *page,
/* Do not let hwpoison pages hit pcplists/buddy */
reset_page_owner(page, order);
page_table_check_free(page, order);
pgalloc_tag_sub(page, 1 << order);
return false;
}
@ -1140,6 +1142,7 @@ __always_inline bool free_pages_prepare(struct page *page,
page->flags &= ~PAGE_FLAGS_CHECK_AT_PREP;
reset_page_owner(page, order);
page_table_check_free(page, order);
pgalloc_tag_sub(page, 1 << order);
if (!PageHighMem(page)) {
debug_check_no_locks_freed(page_address(page),
@ -1533,6 +1536,7 @@ inline void post_alloc_hook(struct page *page, unsigned int order,
set_page_owner(page, order, gfp_flags);
page_table_check_alloc(page, order);
pgalloc_tag_add(page, current, 1 << order);
}
static void prep_new_page(struct page *page, unsigned int order, gfp_t gfp_flags,

4
mm/page_ext.c
View File

@ -10,6 +10,7 @@
#include <linux/page_idle.h>
#include <linux/page_table_check.h>
#include <linux/rcupdate.h>
#include <linux/pgalloc_tag.h>
/*
* struct page extension
@ -82,6 +83,9 @@ static struct page_ext_operations *page_ext_ops[] __initdata = {
#if defined(CONFIG_PAGE_IDLE_FLAG) && !defined(CONFIG_64BIT)
&page_idle_ops,
#endif
#ifdef CONFIG_MEM_ALLOC_PROFILING
&page_alloc_tagging_ops,
#endif
#ifdef CONFIG_PAGE_TABLE_CHECK
&page_table_check_ops,
#endif