Re: [PATCH] mm: optimize memory allocation
On Mon 12-04-21 15:49:53, ultrac...@163.com wrote:
> From: Chen Xiaoguang
>
> Check memory cgroup limit before allocating real memory. This may
> improve performance especially in slow path when memory allocation
> exceeds cgroup limitation.
I would be really curious about any actual numbers because I have really
hard times to see scenarios when this would lead to an improvement.
Effectitelly only non-oom allocations would benefit theoretically (e.g.
atomic or GFP_NORETRY etc). All others will trigger the memcg oom killer
to help forward progress.
Besides that I really dislike kmem and LRU pages to be handled
differently so for that reason
Nacked-by: Michal Hocko
If the optimization really can be provent then the patch would require
to be much more invasive.
> Signed-off-by: Chen Xiaoguang
> Signed-off-by: Chen He
> ---
> include/linux/memcontrol.h | 30 ++
> mm/memcontrol.c| 34 --
> mm/page_alloc.c| 24 +---
> 3 files changed, 55 insertions(+), 33 deletions(-)
>
> diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
> index 0c04d39..59bb3ba 100644
> --- a/include/linux/memcontrol.h
> +++ b/include/linux/memcontrol.h
> @@ -1583,8 +1583,9 @@ static inline void memcg_set_shrinker_bit(struct
> mem_cgroup *memcg,
> #endif
>
> #ifdef CONFIG_MEMCG_KMEM
> -int __memcg_kmem_charge_page(struct page *page, gfp_t gfp, int order);
> -void __memcg_kmem_uncharge_page(struct page *page, int order);
> +int __memcg_kmem_charge_page(struct mem_cgroup *memcg, gfp_t gfp, int order);
> +void __memcg_kmem_uncharge_page(struct page *page, int order,
> + struct mem_cgroup *memcg);
>
> struct obj_cgroup *get_obj_cgroup_from_current(void);
>
> @@ -1610,18 +1611,30 @@ static inline bool memcg_kmem_enabled(void)
> return static_branch_likely(&memcg_kmem_enabled_key);
> }
>
> +extern struct mem_cgroup *get_mem_cgroup_from_current(void);
> +
> static inline int memcg_kmem_charge_page(struct page *page, gfp_t gfp,
>int order)
> {
> - if (memcg_kmem_enabled())
> - return __memcg_kmem_charge_page(page, gfp, order);
> - return 0;
> + struct mem_cgroup *memcg;
> + int ret = 0;
> +
> + memcg = get_mem_cgroup_from_current();
> + if (memcg && memcg_kmem_enabled() && !mem_cgroup_is_root(memcg)) {
> + ret = __memcg_kmem_charge_page(memcg, gfp, order);
> + if (!ret) {
> + page->memcg_data = (unsigned long)memcg |
> MEMCG_DATA_KMEM;
> + return 0;
> + }
> + css_put(&memcg->css);
> + }
> + return ret;
> }
>
> static inline void memcg_kmem_uncharge_page(struct page *page, int order)
> {
> if (memcg_kmem_enabled())
> - __memcg_kmem_uncharge_page(page, order);
> + __memcg_kmem_uncharge_page(page, order, NULL);
> }
>
> /*
> @@ -1647,13 +1660,14 @@ static inline void memcg_kmem_uncharge_page(struct
> page *page, int order)
> {
> }
>
> -static inline int __memcg_kmem_charge_page(struct page *page, gfp_t gfp,
> +static inline int __memcg_kmem_charge_page(struct mem_cgroup *memcg, gfp_t
> gfp,
> int order)
> {
> return 0;
> }
>
> -static inline void __memcg_kmem_uncharge_page(struct page *page, int order)
> +static inline void __memcg_kmem_uncharge_page(struct page *page, int order,
> + struct mem_cgroup *memcg)
> {
> }
>
> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> index e064ac0d..8df57b7 100644
> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -1085,7 +1085,7 @@ static __always_inline bool memcg_kmem_bypass(void)
> /**
> * If active memcg is set, do not fallback to current->mm->memcg.
> */
> -static __always_inline struct mem_cgroup *get_mem_cgroup_from_current(void)
> +struct mem_cgroup *get_mem_cgroup_from_current(void)
> {
> if (memcg_kmem_bypass())
> return NULL;
> @@ -3113,21 +3113,11 @@ static void __memcg_kmem_uncharge(struct mem_cgroup
> *memcg, unsigned int nr_page
> *
> * Returns 0 on success, an error code on failure.
> */
> -int __memcg_kmem_charge_page(struct page *page, gfp_t gfp, int order)
> +int __memcg_kmem_charge_page(struct mem_cgroup *memcg, gfp_t gfp, int order)
> {
> - struct mem_cgroup *memcg;
> - int ret = 0;
> + int ret;
>
> - memcg = get_mem_cgroup_from_current();
> - if (memcg && !mem_cgroup_is_root(memcg)) {
> - ret = __memcg_kmem_charge(memcg, gfp, 1 << order);
> - if (!ret) {
> - page->memcg_data = (unsigned long)memcg |
> - MEMCG_DATA_KMEM;
> - return 0;
> - }
> - css_put(&memcg->css);
> - }
> + ret = __memcg_kmem_charge(memcg, gfp, 1 << order);
>
Re: [PATCH] mm: optimize memory allocation
Hi,
Thank you for the patch! Yet something to improve:
[auto build test ERROR on linux/master]
[also build test ERROR on linus/master v5.12-rc7]
[cannot apply to hnaz-linux-mm/master next-20210409]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]
url:
https://github.com/0day-ci/linux/commits/ultrachin-163-com/mm-optimize-memory-allocation/20210412-155259
base: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
5e46d1b78a03d52306f21f77a4e4a144b6d31486
config: i386-randconfig-r036-20210412 (attached as .config)
compiler: gcc-9 (Debian 9.3.0-22) 9.3.0
reproduce (this is a W=1 build):
#
https://github.com/0day-ci/linux/commit/6994280da115271cf4083439e5d4dcdb3ce00720
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review
ultrachin-163-com/mm-optimize-memory-allocation/20210412-155259
git checkout 6994280da115271cf4083439e5d4dcdb3ce00720
# save the attached .config to linux build tree
make W=1 ARCH=i386
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot
All error/warnings (new ones prefixed by >>):
mm/page_alloc.c:3605:15: warning: no previous prototype for
'should_fail_alloc_page' [-Wmissing-prototypes]
3605 | noinline bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int
order)
| ^~
mm/page_alloc.c: In function '__alloc_pages_nodemask':
>> mm/page_alloc.c:4992:10: error: implicit declaration of function
>> 'get_mem_cgroup_from_current'; did you mean 'get_mem_cgroup_from_mm'?
>> [-Werror=implicit-function-declaration]
4992 | memcg = get_mem_cgroup_from_current();
| ^~~
| get_mem_cgroup_from_mm
>> mm/page_alloc.c:4992:8: warning: assignment to 'struct mem_cgroup *' from
>> 'int' makes pointer from integer without a cast [-Wint-conversion]
4992 | memcg = get_mem_cgroup_from_current();
|^
cc1: some warnings being treated as errors
--
>> mm/memcontrol.c:1088:20: warning: no previous prototype for
>> 'get_mem_cgroup_from_current' [-Wmissing-prototypes]
1088 | struct mem_cgroup *get_mem_cgroup_from_current(void)
|^~~
vim +4992 mm/page_alloc.c
4967
4968 /*
4969 * This is the 'heart' of the zoned buddy allocator.
4970 */
4971 struct page *
4972 __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order, int
preferred_nid,
4973 nodemask_t
*nodemask)
4974 {
4975 struct page *page;
4976 unsigned int alloc_flags = ALLOC_WMARK_LOW;
4977 gfp_t alloc_mask; /* The gfp_t that was actually used for
allocation */
4978 struct alloc_context ac = { };
4979 struct mem_cgroup *memcg;
4980 bool charged = false;
4981
4982 /*
4983 * There are several places where we assume that the order
value is sane
4984 * so bail out early if the request is out of bound.
4985 */
4986 if (unlikely(order >= MAX_ORDER)) {
4987 WARN_ON_ONCE(!(gfp_mask & __GFP_NOWARN));
4988 return NULL;
4989 }
4990
4991 gfp_mask &= gfp_allowed_mask;
> 4992 memcg = get_mem_cgroup_from_current();
4993 if (memcg && memcg_kmem_enabled() && (gfp_mask & __GFP_ACCOUNT)
&&
4994 !mem_cgroup_is_root(memcg)) {
4995 if (unlikely(__memcg_kmem_charge_page(memcg, gfp_mask,
order) != 0)) {
4996 css_put(&memcg->css);
4997 return NULL;
4998 }
4999 charged = true;
5000 }
5001 alloc_mask = gfp_mask;
5002 if (!prepare_alloc_pages(gfp_mask, order, preferred_nid,
nodemask, &ac, &alloc_mask, &alloc_flags))
5003 return NULL;
5004
5005 /*
5006 * Forbid the first pass from falling back to types that
fragment
5007 * memory until all local zones are considered.
5008 */
5009 alloc_flags |=
alloc_flags_nofragment(ac.preferred_zoneref->zone, gfp_mask);
5010
5011 /* First allocation attempt */
5012 page = get_page_from_freelist(alloc_mask, order, alloc_flags,
&ac);
5013 if (likely(page))
5014 goto out;
5015
5016 /*
5017 * Apply scoped allocation constraints. This is mainly about
GFP_NOFS
5018 * resp. GFP_NOIO which has to be inherited for all allocation
requests
5019 * from a particular context which has been marked by
5020 * memalloc_no{fs,io}_{save,
Re: [PATCH] mm: optimize memory allocation
Hi,
Thank you for the patch! Yet something to improve:
[auto build test ERROR on linux/master]
[also build test ERROR on linus/master v5.12-rc7]
[cannot apply to hnaz-linux-mm/master next-20210409]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]
url:
https://github.com/0day-ci/linux/commits/ultrachin-163-com/mm-optimize-memory-allocation/20210412-155259
base: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
5e46d1b78a03d52306f21f77a4e4a144b6d31486
config: openrisc-randconfig-r032-20210412 (attached as .config)
compiler: or1k-linux-gcc (GCC) 9.3.0
reproduce (this is a W=1 build):
wget
https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O
~/bin/make.cross
chmod +x ~/bin/make.cross
#
https://github.com/0day-ci/linux/commit/6994280da115271cf4083439e5d4dcdb3ce00720
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review
ultrachin-163-com/mm-optimize-memory-allocation/20210412-155259
git checkout 6994280da115271cf4083439e5d4dcdb3ce00720
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross
ARCH=openrisc
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot
All errors (new ones prefixed by >>):
mm/page_alloc.c:3605:15: warning: no previous prototype for
'should_fail_alloc_page' [-Wmissing-prototypes]
3605 | noinline bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int
order)
| ^~
mm/page_alloc.c: In function '__alloc_pages_nodemask':
mm/page_alloc.c:4992:10: error: implicit declaration of function
'get_mem_cgroup_from_current'; did you mean 'get_mem_cgroup_from_mm'?
[-Werror=implicit-function-declaration]
4992 | memcg = get_mem_cgroup_from_current();
| ^~~
| get_mem_cgroup_from_mm
mm/page_alloc.c:4992:8: warning: assignment to 'struct mem_cgroup *' from
'int' makes pointer from integer without a cast [-Wint-conversion]
4992 | memcg = get_mem_cgroup_from_current();
|^
>> mm/page_alloc.c:4996:18: error: dereferencing pointer to incomplete type
>> 'struct mem_cgroup'
4996 |css_put(&memcg->css);
| ^~
>> mm/page_alloc.c:5035:7: error: 'struct page' has no member named 'memcg_data'
5035 | page->memcg_data = (unsigned long)memcg | MEMCG_DATA_KMEM;
| ^~
>> mm/page_alloc.c:5035:45: error: 'MEMCG_DATA_KMEM' undeclared (first use in
>> this function)
5035 | page->memcg_data = (unsigned long)memcg | MEMCG_DATA_KMEM;
| ^~~
mm/page_alloc.c:5035:45: note: each undeclared identifier is reported only
once for each function it appears in
cc1: some warnings being treated as errors
vim +4996 mm/page_alloc.c
4967
4968 /*
4969 * This is the 'heart' of the zoned buddy allocator.
4970 */
4971 struct page *
4972 __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order, int
preferred_nid,
4973 nodemask_t
*nodemask)
4974 {
4975 struct page *page;
4976 unsigned int alloc_flags = ALLOC_WMARK_LOW;
4977 gfp_t alloc_mask; /* The gfp_t that was actually used for
allocation */
4978 struct alloc_context ac = { };
4979 struct mem_cgroup *memcg;
4980 bool charged = false;
4981
4982 /*
4983 * There are several places where we assume that the order
value is sane
4984 * so bail out early if the request is out of bound.
4985 */
4986 if (unlikely(order >= MAX_ORDER)) {
4987 WARN_ON_ONCE(!(gfp_mask & __GFP_NOWARN));
4988 return NULL;
4989 }
4990
4991 gfp_mask &= gfp_allowed_mask;
> 4992 memcg = get_mem_cgroup_from_current();
4993 if (memcg && memcg_kmem_enabled() && (gfp_mask & __GFP_ACCOUNT)
&&
4994 !mem_cgroup_is_root(memcg)) {
4995 if (unlikely(__memcg_kmem_charge_page(memcg, gfp_mask,
order) != 0)) {
> 4996 css_put(&memcg->css);
4997 return NULL;
4998 }
4999 charged = true;
5000 }
5001 alloc_mask = gfp_mask;
5002 if (!prepare_alloc_pages(gfp_mask, order, preferred_nid,
nodemask, &ac, &alloc_mask, &alloc_flags))
5003 return NULL;
5004
5005 /*
5006 * Forbid the first pass from falling back to types that
fragment
5007 * memory until all local zones are considered.
500
[PATCH] mm: optimize memory allocation
From: Chen Xiaoguang
Check memory cgroup limit before allocating real memory. This may
improve performance especially in slow path when memory allocation
exceeds cgroup limitation.
Signed-off-by: Chen Xiaoguang
Signed-off-by: Chen He
---
include/linux/memcontrol.h | 30 ++
mm/memcontrol.c| 34 --
mm/page_alloc.c| 24 +---
3 files changed, 55 insertions(+), 33 deletions(-)
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 0c04d39..59bb3ba 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -1583,8 +1583,9 @@ static inline void memcg_set_shrinker_bit(struct
mem_cgroup *memcg,
#endif
#ifdef CONFIG_MEMCG_KMEM
-int __memcg_kmem_charge_page(struct page *page, gfp_t gfp, int order);
-void __memcg_kmem_uncharge_page(struct page *page, int order);
+int __memcg_kmem_charge_page(struct mem_cgroup *memcg, gfp_t gfp, int order);
+void __memcg_kmem_uncharge_page(struct page *page, int order,
+ struct mem_cgroup *memcg);
struct obj_cgroup *get_obj_cgroup_from_current(void);
@@ -1610,18 +1611,30 @@ static inline bool memcg_kmem_enabled(void)
return static_branch_likely(&memcg_kmem_enabled_key);
}
+extern struct mem_cgroup *get_mem_cgroup_from_current(void);
+
static inline int memcg_kmem_charge_page(struct page *page, gfp_t gfp,
int order)
{
- if (memcg_kmem_enabled())
- return __memcg_kmem_charge_page(page, gfp, order);
- return 0;
+ struct mem_cgroup *memcg;
+ int ret = 0;
+
+ memcg = get_mem_cgroup_from_current();
+ if (memcg && memcg_kmem_enabled() && !mem_cgroup_is_root(memcg)) {
+ ret = __memcg_kmem_charge_page(memcg, gfp, order);
+ if (!ret) {
+ page->memcg_data = (unsigned long)memcg |
MEMCG_DATA_KMEM;
+ return 0;
+ }
+ css_put(&memcg->css);
+ }
+ return ret;
}
static inline void memcg_kmem_uncharge_page(struct page *page, int order)
{
if (memcg_kmem_enabled())
- __memcg_kmem_uncharge_page(page, order);
+ __memcg_kmem_uncharge_page(page, order, NULL);
}
/*
@@ -1647,13 +1660,14 @@ static inline void memcg_kmem_uncharge_page(struct page
*page, int order)
{
}
-static inline int __memcg_kmem_charge_page(struct page *page, gfp_t gfp,
+static inline int __memcg_kmem_charge_page(struct mem_cgroup *memcg, gfp_t gfp,
int order)
{
return 0;
}
-static inline void __memcg_kmem_uncharge_page(struct page *page, int order)
+static inline void __memcg_kmem_uncharge_page(struct page *page, int order,
+ struct mem_cgroup *memcg)
{
}
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index e064ac0d..8df57b7 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1085,7 +1085,7 @@ static __always_inline bool memcg_kmem_bypass(void)
/**
* If active memcg is set, do not fallback to current->mm->memcg.
*/
-static __always_inline struct mem_cgroup *get_mem_cgroup_from_current(void)
+struct mem_cgroup *get_mem_cgroup_from_current(void)
{
if (memcg_kmem_bypass())
return NULL;
@@ -3113,21 +3113,11 @@ static void __memcg_kmem_uncharge(struct mem_cgroup
*memcg, unsigned int nr_page
*
* Returns 0 on success, an error code on failure.
*/
-int __memcg_kmem_charge_page(struct page *page, gfp_t gfp, int order)
+int __memcg_kmem_charge_page(struct mem_cgroup *memcg, gfp_t gfp, int order)
{
- struct mem_cgroup *memcg;
- int ret = 0;
+ int ret;
- memcg = get_mem_cgroup_from_current();
- if (memcg && !mem_cgroup_is_root(memcg)) {
- ret = __memcg_kmem_charge(memcg, gfp, 1 << order);
- if (!ret) {
- page->memcg_data = (unsigned long)memcg |
- MEMCG_DATA_KMEM;
- return 0;
- }
- css_put(&memcg->css);
- }
+ ret = __memcg_kmem_charge(memcg, gfp, 1 << order);
return ret;
}
@@ -3136,17 +3126,25 @@ int __memcg_kmem_charge_page(struct page *page, gfp_t
gfp, int order)
* @page: page to uncharge
* @order: allocation order
*/
-void __memcg_kmem_uncharge_page(struct page *page, int order)
+void __memcg_kmem_uncharge_page(struct page *page, int order,
+ struct mem_cgroup *memcg_in)
{
- struct mem_cgroup *memcg = page_memcg(page);
+ struct mem_cgroup *memcg;
unsigned int nr_pages = 1 << order;
+ if (page)
+ memcg = page_memcg(page);
+ else
+ memcg = memcg_in;
+
if (!memcg)
return;
- VM_BUG_ON_PAGE(mem_cgroup_is_root(memcg), page);
+ if (page)
+ VM_BUG_ON_PAGE(mem
