[v2,05/13] mm: Move memcg stack accounting to account_kernel_stack
diff mbox

Message ID 8a17889a9d47b7b4deb41f2fcccada8bf54d4b6f.1466192946.git.luto@kernel.org
State New
Headers show

Commit Message

Andy Lutomirski June 17, 2016, 8 p.m. UTC
We should account for stacks regardless of stack size.  Move it into
account_kernel_stack.

Fixes: 12580e4b54ba8 ("mm: memcontrol: report kernel stack usage in cgroup2 memory.stat")
Cc: Vladimir Davydov <vdavydov@virtuozzo.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: linux-mm@kvack.org
Signed-off-by: Andy Lutomirski <luto@kernel.org>
---
 kernel/fork.c | 15 ++++++---------
 1 file changed, 6 insertions(+), 9 deletions(-)

Comments

Josh Poimboeuf June 17, 2016, 8:55 p.m. UTC | #1
On Fri, Jun 17, 2016 at 01:00:41PM -0700, Andy Lutomirski wrote:
> We should account for stacks regardless of stack size.  Move it into
> account_kernel_stack.
> 
> Fixes: 12580e4b54ba8 ("mm: memcontrol: report kernel stack usage in cgroup2 memory.stat")
> Cc: Vladimir Davydov <vdavydov@virtuozzo.com>
> Cc: Johannes Weiner <hannes@cmpxchg.org>
> Cc: Michal Hocko <mhocko@kernel.org>
> Cc: linux-mm@kvack.org
> Signed-off-by: Andy Lutomirski <luto@kernel.org>
> ---
>  kernel/fork.c | 15 ++++++---------
>  1 file changed, 6 insertions(+), 9 deletions(-)
> 
> diff --git a/kernel/fork.c b/kernel/fork.c
> index be7f006af727..cd2abe6e4e41 100644
> --- a/kernel/fork.c
> +++ b/kernel/fork.c
> @@ -165,20 +165,12 @@ static struct thread_info *alloc_thread_info_node(struct task_struct *tsk,
>  	struct page *page = alloc_kmem_pages_node(node, THREADINFO_GFP,
>  						  THREAD_SIZE_ORDER);
>  
> -	if (page)
> -		memcg_kmem_update_page_stat(page, MEMCG_KERNEL_STACK,
> -					    1 << THREAD_SIZE_ORDER);
> -
>  	return page ? page_address(page) : NULL;
>  }
>  
>  static inline void free_thread_info(struct thread_info *ti)
>  {
> -	struct page *page = virt_to_page(ti);
> -
> -	memcg_kmem_update_page_stat(page, MEMCG_KERNEL_STACK,
> -				    -(1 << THREAD_SIZE_ORDER));
> -	__free_kmem_pages(page, THREAD_SIZE_ORDER);
> +	free_kmem_pages((unsigned long)ti, THREAD_SIZE_ORDER);
>  }
>  # else
>  static struct kmem_cache *thread_info_cache;
> @@ -227,6 +219,11 @@ static void account_kernel_stack(struct thread_info *ti, int account)
>  
>  	mod_zone_page_state(zone, NR_KERNEL_STACK_KB,
>  			    THREAD_SIZE / 1024 * account);
> +
> +	/* All stack pages belong to the same memcg. */
> +	memcg_kmem_update_page_stat(
> +		virt_to_page(ti), MEMCG_KERNEL_STACK,
> +		account * (THREAD_SIZE / PAGE_SIZE));
>  }

Won't this be broken in the case where THREAD_SIZE < PAGE_SIZE?
Andy Lutomirski June 17, 2016, 10:18 p.m. UTC | #2
On Fri, Jun 17, 2016 at 1:55 PM, Josh Poimboeuf <jpoimboe@redhat.com> wrote:
> On Fri, Jun 17, 2016 at 01:00:41PM -0700, Andy Lutomirski wrote:
>> We should account for stacks regardless of stack size.  Move it into
>> account_kernel_stack.
>>
>> Fixes: 12580e4b54ba8 ("mm: memcontrol: report kernel stack usage in cgroup2 memory.stat")
>> Cc: Vladimir Davydov <vdavydov@virtuozzo.com>
>> Cc: Johannes Weiner <hannes@cmpxchg.org>
>> Cc: Michal Hocko <mhocko@kernel.org>
>> Cc: linux-mm@kvack.org
>> Signed-off-by: Andy Lutomirski <luto@kernel.org>
>> ---
>>  kernel/fork.c | 15 ++++++---------
>>  1 file changed, 6 insertions(+), 9 deletions(-)
>>
>> diff --git a/kernel/fork.c b/kernel/fork.c
>> index be7f006af727..cd2abe6e4e41 100644
>> --- a/kernel/fork.c
>> +++ b/kernel/fork.c
>> @@ -165,20 +165,12 @@ static struct thread_info *alloc_thread_info_node(struct task_struct *tsk,
>>       struct page *page = alloc_kmem_pages_node(node, THREADINFO_GFP,
>>                                                 THREAD_SIZE_ORDER);
>>
>> -     if (page)
>> -             memcg_kmem_update_page_stat(page, MEMCG_KERNEL_STACK,
>> -                                         1 << THREAD_SIZE_ORDER);
>> -
>>       return page ? page_address(page) : NULL;
>>  }
>>
>>  static inline void free_thread_info(struct thread_info *ti)
>>  {
>> -     struct page *page = virt_to_page(ti);
>> -
>> -     memcg_kmem_update_page_stat(page, MEMCG_KERNEL_STACK,
>> -                                 -(1 << THREAD_SIZE_ORDER));
>> -     __free_kmem_pages(page, THREAD_SIZE_ORDER);
>> +     free_kmem_pages((unsigned long)ti, THREAD_SIZE_ORDER);
>>  }
>>  # else
>>  static struct kmem_cache *thread_info_cache;
>> @@ -227,6 +219,11 @@ static void account_kernel_stack(struct thread_info *ti, int account)
>>
>>       mod_zone_page_state(zone, NR_KERNEL_STACK_KB,
>>                           THREAD_SIZE / 1024 * account);
>> +
>> +     /* All stack pages belong to the same memcg. */
>> +     memcg_kmem_update_page_stat(
>> +             virt_to_page(ti), MEMCG_KERNEL_STACK,
>> +             account * (THREAD_SIZE / PAGE_SIZE));
>>  }
>
> Won't this be broken in the case where THREAD_SIZE < PAGE_SIZE?

In my defense, it was broken before this change, too.  Sigh.  I'll
change this to count in KiB too.

As far as I can tell, this thing is used for display only.

--Andy
Michal Hocko June 20, 2016, 1:02 p.m. UTC | #3
On Fri 17-06-16 13:00:41, Andy Lutomirski wrote:
> We should account for stacks regardless of stack size.  Move it into
> account_kernel_stack.
> 
> Fixes: 12580e4b54ba8 ("mm: memcontrol: report kernel stack usage in cgroup2 memory.stat")
> Cc: Vladimir Davydov <vdavydov@virtuozzo.com>
> Cc: Johannes Weiner <hannes@cmpxchg.org>
> Cc: Michal Hocko <mhocko@kernel.org>
> Cc: linux-mm@kvack.org
> Signed-off-by: Andy Lutomirski <luto@kernel.org>

Acked-by: Michal Hocko <mhocko@suse.com>

> ---
>  kernel/fork.c | 15 ++++++---------
>  1 file changed, 6 insertions(+), 9 deletions(-)
> 
> diff --git a/kernel/fork.c b/kernel/fork.c
> index be7f006af727..cd2abe6e4e41 100644
> --- a/kernel/fork.c
> +++ b/kernel/fork.c
> @@ -165,20 +165,12 @@ static struct thread_info *alloc_thread_info_node(struct task_struct *tsk,
>  	struct page *page = alloc_kmem_pages_node(node, THREADINFO_GFP,
>  						  THREAD_SIZE_ORDER);
>  
> -	if (page)
> -		memcg_kmem_update_page_stat(page, MEMCG_KERNEL_STACK,
> -					    1 << THREAD_SIZE_ORDER);
> -
>  	return page ? page_address(page) : NULL;
>  }
>  
>  static inline void free_thread_info(struct thread_info *ti)
>  {
> -	struct page *page = virt_to_page(ti);
> -
> -	memcg_kmem_update_page_stat(page, MEMCG_KERNEL_STACK,
> -				    -(1 << THREAD_SIZE_ORDER));
> -	__free_kmem_pages(page, THREAD_SIZE_ORDER);
> +	free_kmem_pages((unsigned long)ti, THREAD_SIZE_ORDER);
>  }
>  # else
>  static struct kmem_cache *thread_info_cache;
> @@ -227,6 +219,11 @@ static void account_kernel_stack(struct thread_info *ti, int account)
>  
>  	mod_zone_page_state(zone, NR_KERNEL_STACK_KB,
>  			    THREAD_SIZE / 1024 * account);
> +
> +	/* All stack pages belong to the same memcg. */
> +	memcg_kmem_update_page_stat(
> +		virt_to_page(ti), MEMCG_KERNEL_STACK,
> +		account * (THREAD_SIZE / PAGE_SIZE));
>  }
>  
>  void free_task(struct task_struct *tsk)
> -- 
> 2.5.5
Andy Lutomirski June 20, 2016, 4:05 p.m. UTC | #4
On Jun 20, 2016 6:02 AM, "Michal Hocko" <mhocko@kernel.org> wrote:
>
> On Fri 17-06-16 13:00:41, Andy Lutomirski wrote:
> > We should account for stacks regardless of stack size.  Move it into
> > account_kernel_stack.
> >
> > Fixes: 12580e4b54ba8 ("mm: memcontrol: report kernel stack usage in cgroup2 memory.stat")
> > Cc: Vladimir Davydov <vdavydov@virtuozzo.com>
> > Cc: Johannes Weiner <hannes@cmpxchg.org>
> > Cc: Michal Hocko <mhocko@kernel.org>
> > Cc: linux-mm@kvack.org
> > Signed-off-by: Andy Lutomirski <luto@kernel.org>
>
> Acked-by: Michal Hocko <mhocko@suse.com>
>

This needs the same kilobyte treatment as the other accounting patch,
so I'm going to send v3 without your ack.

--Andy

Patch
diff mbox

diff --git a/kernel/fork.c b/kernel/fork.c
index be7f006af727..cd2abe6e4e41 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -165,20 +165,12 @@  static struct thread_info *alloc_thread_info_node(struct task_struct *tsk,
 	struct page *page = alloc_kmem_pages_node(node, THREADINFO_GFP,
 						  THREAD_SIZE_ORDER);
 
-	if (page)
-		memcg_kmem_update_page_stat(page, MEMCG_KERNEL_STACK,
-					    1 << THREAD_SIZE_ORDER);
-
 	return page ? page_address(page) : NULL;
 }
 
 static inline void free_thread_info(struct thread_info *ti)
 {
-	struct page *page = virt_to_page(ti);
-
-	memcg_kmem_update_page_stat(page, MEMCG_KERNEL_STACK,
-				    -(1 << THREAD_SIZE_ORDER));
-	__free_kmem_pages(page, THREAD_SIZE_ORDER);
+	free_kmem_pages((unsigned long)ti, THREAD_SIZE_ORDER);
 }
 # else
 static struct kmem_cache *thread_info_cache;
@@ -227,6 +219,11 @@  static void account_kernel_stack(struct thread_info *ti, int account)
 
 	mod_zone_page_state(zone, NR_KERNEL_STACK_KB,
 			    THREAD_SIZE / 1024 * account);
+
+	/* All stack pages belong to the same memcg. */
+	memcg_kmem_update_page_stat(
+		virt_to_page(ti), MEMCG_KERNEL_STACK,
+		account * (THREAD_SIZE / PAGE_SIZE));
 }
 
 void free_task(struct task_struct *tsk)