The patch titled
Subject: mm-page_owner-decouple-freeing-stack-trace-from-debug_pagealloc-v3
has been added to the -mm tree. Its filename is
mm-page_owner-decouple-freeing-stack-trace-from-debug_pagealloc-v3.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-page_owner-decouple-freeing-stack-trace-from-debug_pagealloc-v3.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-page_owner-decouple-freeing-stack-trace-from-debug_pagealloc-v3.patch
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------------------------------------------------------
From: Vlastimil Babka <vbabka@xxxxxxx>
Subject: mm-page_owner-decouple-freeing-stack-trace-from-debug_pagealloc-v3
Qian Cai suggested that the extra boot option and page_ext ops is
unnecessary for a debugging option, unless somebody really complains about
the overhead, with numbers. So patch 2 is greatly simplified.
Link: http://lkml.kernel.org/r/20191007091808.7096-3-vbabka@xxxxxxx
Signed-off-by: Vlastimil Babka <vbabka@xxxxxxx>
Suggested-by: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
Suggested-by: Walter Wu <walter-zh.wu@xxxxxxxxxxxx>
Suggested-by: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx>
Suggested-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Suggested-by: Qian Cai <cai@xxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
Documentation/admin-guide/kernel-parameters.txt | 8 -
include/linux/page_owner.h | 1
mm/page_ext.c | 1
mm/page_owner.c | 76 ++------------
4 files changed, 11 insertions(+), 75 deletions(-)
--- a/Documentation/admin-guide/kernel-parameters.txt~mm-page_owner-decouple-freeing-stack-trace-from-debug_pagealloc-v3
+++ a/Documentation/admin-guide/kernel-parameters.txt
@@ -3246,14 +3246,6 @@
we can turn it on.
on: enable the feature
- page_owner_free=
- [KNL] When enabled together with page_owner, store also
- the stack of who frees a page, for error page dump
- purposes. This is also implicitly enabled by
- debug_pagealloc=on or KASAN, so only page_owner=on is
- sufficient in those cases.
- on: enable the feature
-
page_poison= [KNL] Boot-time parameter changing the state of
poisoning on the buddy allocator, available with
CONFIG_PAGE_POISONING=y.
--- a/include/linux/page_owner.h~mm-page_owner-decouple-freeing-stack-trace-from-debug_pagealloc-v3
+++ a/include/linux/page_owner.h
@@ -7,7 +7,6 @@
#ifdef CONFIG_PAGE_OWNER
extern struct static_key_false page_owner_inited;
extern struct page_ext_operations page_owner_ops;
-extern struct page_ext_operations page_owner_free_ops;
extern void __reset_page_owner(struct page *page, unsigned int order);
extern void __set_page_owner(struct page *page,
--- a/mm/page_ext.c~mm-page_owner-decouple-freeing-stack-trace-from-debug_pagealloc-v3
+++ a/mm/page_ext.c
@@ -61,7 +61,6 @@
static struct page_ext_operations *page_ext_ops[] = {
#ifdef CONFIG_PAGE_OWNER
&page_owner_ops,
- &page_owner_free_ops,
#endif
#if defined(CONFIG_IDLE_PAGE_TRACKING) && !defined(CONFIG_64BIT)
&page_idle_ops,
--- a/mm/page_owner.c~mm-page_owner-decouple-freeing-stack-trace-from-debug_pagealloc-v3
+++ a/mm/page_owner.c
@@ -24,16 +24,11 @@ struct page_owner {
short last_migrate_reason;
gfp_t gfp_mask;
depot_stack_handle_t handle;
-};
-
-struct page_owner_free {
depot_stack_handle_t free_handle;
};
static bool page_owner_enabled = false;
-static bool page_owner_free_enabled = false;
DEFINE_STATIC_KEY_FALSE(page_owner_inited);
-static DEFINE_STATIC_KEY_FALSE(page_owner_free_stack);
static depot_stack_handle_t dummy_handle;
static depot_stack_handle_t failure_handle;
@@ -58,29 +53,6 @@ static bool need_page_owner(void)
return page_owner_enabled;
}
-static int __init early_page_owner_free_param(char *buf)
-{
- if (!buf)
- return -EINVAL;
-
- if (strcmp(buf, "on") == 0)
- page_owner_free_enabled = true;
-
- return 0;
-}
-early_param("page_owner_free", early_page_owner_free_param);
-
-static bool need_page_owner_free(void) {
-
- if (!page_owner_enabled)
- return false;
-
- if (IS_ENABLED(CONFIG_KASAN) || debug_pagealloc_enabled())
- page_owner_free_enabled = true;
-
- return page_owner_free_enabled;
-}
-
static __always_inline depot_stack_handle_t create_dummy_stack(void)
{
unsigned long entries[4];
@@ -117,36 +89,17 @@ static void init_page_owner(void)
init_early_allocated_pages();
}
-static void init_page_owner_free(void)
-{
- if (!page_owner_enabled || !page_owner_free_enabled)
- return;
-
- static_branch_enable(&page_owner_free_stack);
-}
-
struct page_ext_operations page_owner_ops = {
.size = sizeof(struct page_owner),
.need = need_page_owner,
.init = init_page_owner,
};
-struct page_ext_operations page_owner_free_ops = {
- .size = sizeof(struct page_owner_free),
- .need = need_page_owner_free,
- .init = init_page_owner_free,
-};
-
static inline struct page_owner *get_page_owner(struct page_ext *page_ext)
{
return (void *)page_ext + page_owner_ops.offset;
}
-static inline struct page_owner_free *get_page_owner_free(struct page_ext *page_ext)
-{
- return (void *)page_ext + page_owner_free_ops.offset;
-}
-
static inline bool check_recursive_alloc(unsigned long *entries,
unsigned int nr_entries,
unsigned long ip)
@@ -191,20 +144,17 @@ void __reset_page_owner(struct page *pag
int i;
struct page_ext *page_ext;
depot_stack_handle_t handle = 0;
- struct page_owner_free *page_owner_free;
+ struct page_owner *page_owner;
- if (static_branch_unlikely(&page_owner_free_stack))
- handle = save_stack(GFP_NOWAIT | __GFP_NOWARN);
+ handle = save_stack(GFP_NOWAIT | __GFP_NOWARN);
page_ext = lookup_page_ext(page);
if (unlikely(!page_ext))
return;
for (i = 0; i < (1 << order); i++) {
__clear_bit(PAGE_EXT_OWNER_ACTIVE, &page_ext->flags);
- if (static_branch_unlikely(&page_owner_free_stack)) {
- page_owner_free = get_page_owner_free(page_ext);
- page_owner_free->free_handle = handle;
- }
+ page_owner = get_page_owner(page_ext);
+ page_owner->free_handle = handle;
page_ext = page_ext_next(page_ext);
}
}
@@ -452,7 +402,6 @@ void __dump_page_owner(struct page *page
{
struct page_ext *page_ext = lookup_page_ext(page);
struct page_owner *page_owner;
- struct page_owner_free *page_owner_free;
depot_stack_handle_t handle;
unsigned long *entries;
unsigned int nr_entries;
@@ -489,16 +438,13 @@ void __dump_page_owner(struct page *page
stack_trace_print(entries, nr_entries, 0);
}
- if (static_branch_unlikely(&page_owner_free_stack)) {
- page_owner_free = get_page_owner_free(page_ext);
- handle = READ_ONCE(page_owner_free->free_handle);
- if (!handle) {
- pr_alert("page_owner free stack trace missing\n");
- } else {
- nr_entries = stack_depot_fetch(handle, &entries);
- pr_alert("page last free stack trace:\n");
- stack_trace_print(entries, nr_entries, 0);
- }
+ handle = READ_ONCE(page_owner->free_handle);
+ if (!handle) {
+ pr_alert("page_owner free stack trace missing\n");
+ } else {
+ nr_entries = stack_depot_fetch(handle, &entries);
+ pr_alert("page last free stack trace:\n");
+ stack_trace_print(entries, nr_entries, 0);
}
if (page_owner->last_migrate_reason != -1)
_
Patches currently in -mm which might be from vbabka@xxxxxxx are
mm-slb-improve-memory-accounting.patch
mm-slb-guarantee-natural-alignment-for-kmallocpower-of-two.patch
mm-page_owner-fix-off-by-one-error-in-__set_page_owner_handle.patch
mm-page_owner-decouple-freeing-stack-trace-from-debug_pagealloc.patch
mm-page_owner-decouple-freeing-stack-trace-from-debug_pagealloc-v3.patch
mm-page_owner-rename-flag-indicating-that-page-is-allocated.patch
