diff mbox series

[PATCH-next] mm, memcg: Add ":deact" tag for reparented kmem caches in memcg_slabinfo

Message ID 20190621173005.31514-1-longman@redhat.com (mailing list archive)
State New, archived
Headers show
Series [PATCH-next] mm, memcg: Add ":deact" tag for reparented kmem caches in memcg_slabinfo | expand

Commit Message

Waiman Long June 21, 2019, 5:30 p.m. UTC
With Roman's kmem cache reparent patch, multiple kmem caches of the same
type can be seen attached to the same memcg id. All of them, except
maybe one, are reparent'ed kmem caches. It can be useful to tag those
reparented caches by adding a new slab flag "SLAB_DEACTIVATED" to those
kmem caches that will be reparent'ed if it cannot be destroyed completely.

For the reparent'ed memcg kmem caches, the tag ":deact" will now be
shown in <debugfs>/memcg_slabinfo.

Signed-off-by: Waiman Long <longman@redhat.com>
---
 include/linux/slab.h |  4 ++++
 mm/slab.c            |  1 +
 mm/slab_common.c     | 14 ++++++++------
 mm/slub.c            |  1 +
 4 files changed, 14 insertions(+), 6 deletions(-)

Comments

Shakeel Butt June 22, 2019, 2:56 a.m. UTC | #1
On Fri, Jun 21, 2019 at 10:30 AM Waiman Long <longman@redhat.com> wrote:
>
> With Roman's kmem cache reparent patch, multiple kmem caches of the same
> type can be seen attached to the same memcg id. All of them, except
> maybe one, are reparent'ed kmem caches. It can be useful to tag those
> reparented caches by adding a new slab flag "SLAB_DEACTIVATED" to those
> kmem caches that will be reparent'ed if it cannot be destroyed completely.
>
> For the reparent'ed memcg kmem caches, the tag ":deact" will now be
> shown in <debugfs>/memcg_slabinfo.
>
> Signed-off-by: Waiman Long <longman@redhat.com>

Reviewed-by: Shakeel Butt <shakeelb@google.com>

> ---
>  include/linux/slab.h |  4 ++++
>  mm/slab.c            |  1 +
>  mm/slab_common.c     | 14 ++++++++------
>  mm/slub.c            |  1 +
>  4 files changed, 14 insertions(+), 6 deletions(-)
>
> diff --git a/include/linux/slab.h b/include/linux/slab.h
> index fecf40b7be69..19ab1380f875 100644
> --- a/include/linux/slab.h
> +++ b/include/linux/slab.h
> @@ -116,6 +116,10 @@
>  /* Objects are reclaimable */
>  #define SLAB_RECLAIM_ACCOUNT   ((slab_flags_t __force)0x00020000U)
>  #define SLAB_TEMPORARY         SLAB_RECLAIM_ACCOUNT    /* Objects are short-lived */
> +
> +/* Slab deactivation flag */
> +#define SLAB_DEACTIVATED       ((slab_flags_t __force)0x10000000U)
> +
>  /*
>   * ZERO_SIZE_PTR will be returned for zero sized kmalloc requests.
>   *
> diff --git a/mm/slab.c b/mm/slab.c
> index a2e93adf1df0..e8c7743fc283 100644
> --- a/mm/slab.c
> +++ b/mm/slab.c
> @@ -2245,6 +2245,7 @@ int __kmem_cache_shrink(struct kmem_cache *cachep)
>  #ifdef CONFIG_MEMCG
>  void __kmemcg_cache_deactivate(struct kmem_cache *cachep)
>  {
> +       cachep->flags |= SLAB_DEACTIVATED;
>         __kmem_cache_shrink(cachep);
>  }
>
> diff --git a/mm/slab_common.c b/mm/slab_common.c
> index 146d8eaa639c..85cf0c374303 100644
> --- a/mm/slab_common.c
> +++ b/mm/slab_common.c
> @@ -1533,7 +1533,7 @@ static int memcg_slabinfo_show(struct seq_file *m, void *unused)
>         struct slabinfo sinfo;
>
>         mutex_lock(&slab_mutex);
> -       seq_puts(m, "# <name> <css_id[:dead]> <active_objs> <num_objs>");
> +       seq_puts(m, "# <name> <css_id[:dead|deact]> <active_objs> <num_objs>");
>         seq_puts(m, " <active_slabs> <num_slabs>\n");
>         list_for_each_entry(s, &slab_root_caches, root_caches_node) {
>                 /*
> @@ -1544,22 +1544,24 @@ static int memcg_slabinfo_show(struct seq_file *m, void *unused)
>
>                 memset(&sinfo, 0, sizeof(sinfo));
>                 get_slabinfo(s, &sinfo);
> -               seq_printf(m, "%-17s root      %6lu %6lu %6lu %6lu\n",
> +               seq_printf(m, "%-17s root       %6lu %6lu %6lu %6lu\n",
>                            cache_name(s), sinfo.active_objs, sinfo.num_objs,
>                            sinfo.active_slabs, sinfo.num_slabs);
>
>                 for_each_memcg_cache(c, s) {
>                         struct cgroup_subsys_state *css;
> -                       char *dead = "";
> +                       char *status = "";
>
>                         css = &c->memcg_params.memcg->css;
>                         if (!(css->flags & CSS_ONLINE))
> -                               dead = ":dead";
> +                               status = ":dead";
> +                       else if (c->flags & SLAB_DEACTIVATED)
> +                               status = ":deact";
>
>                         memset(&sinfo, 0, sizeof(sinfo));
>                         get_slabinfo(c, &sinfo);
> -                       seq_printf(m, "%-17s %4d%5s %6lu %6lu %6lu %6lu\n",
> -                                  cache_name(c), css->id, dead,
> +                       seq_printf(m, "%-17s %4d%-6s %6lu %6lu %6lu %6lu\n",
> +                                  cache_name(c), css->id, status,
>                                    sinfo.active_objs, sinfo.num_objs,
>                                    sinfo.active_slabs, sinfo.num_slabs);
>                 }
> diff --git a/mm/slub.c b/mm/slub.c
> index a384228ff6d3..c965b4413658 100644
> --- a/mm/slub.c
> +++ b/mm/slub.c
> @@ -4057,6 +4057,7 @@ void __kmemcg_cache_deactivate(struct kmem_cache *s)
>          */
>         slub_set_cpu_partial(s, 0);
>         s->min_partial = 0;
> +       s->flags |= SLAB_DEACTIVATED;
>  }
>  #endif /* CONFIG_MEMCG */
>
> --
> 2.18.1
>
Roman Gushchin June 26, 2019, 7:58 p.m. UTC | #2
On Fri, Jun 21, 2019 at 01:30:05PM -0400, Waiman Long wrote:
> With Roman's kmem cache reparent patch, multiple kmem caches of the same
> type can be seen attached to the same memcg id. All of them, except
> maybe one, are reparent'ed kmem caches. It can be useful to tag those
> reparented caches by adding a new slab flag "SLAB_DEACTIVATED" to those
> kmem caches that will be reparent'ed if it cannot be destroyed completely.
> 
> For the reparent'ed memcg kmem caches, the tag ":deact" will now be
> shown in <debugfs>/memcg_slabinfo.
> 
> Signed-off-by: Waiman Long <longman@redhat.com>

Hi Waiman!

Sorry for the late reply. The patch overall looks good to me,
except one nit. Please feel free to use my ack:
Acked-by: Roman Gushchin <guro@fb.com>

> ---
>  include/linux/slab.h |  4 ++++
>  mm/slab.c            |  1 +
>  mm/slab_common.c     | 14 ++++++++------
>  mm/slub.c            |  1 +
>  4 files changed, 14 insertions(+), 6 deletions(-)
> 
> diff --git a/include/linux/slab.h b/include/linux/slab.h
> index fecf40b7be69..19ab1380f875 100644
> --- a/include/linux/slab.h
> +++ b/include/linux/slab.h
> @@ -116,6 +116,10 @@
>  /* Objects are reclaimable */
>  #define SLAB_RECLAIM_ACCOUNT	((slab_flags_t __force)0x00020000U)
>  #define SLAB_TEMPORARY		SLAB_RECLAIM_ACCOUNT	/* Objects are short-lived */
> +
> +/* Slab deactivation flag */
> +#define SLAB_DEACTIVATED	((slab_flags_t __force)0x10000000U)
> +
>  /*
>   * ZERO_SIZE_PTR will be returned for zero sized kmalloc requests.
>   *
> diff --git a/mm/slab.c b/mm/slab.c
> index a2e93adf1df0..e8c7743fc283 100644
> --- a/mm/slab.c
> +++ b/mm/slab.c
> @@ -2245,6 +2245,7 @@ int __kmem_cache_shrink(struct kmem_cache *cachep)
>  #ifdef CONFIG_MEMCG
>  void __kmemcg_cache_deactivate(struct kmem_cache *cachep)
>  {
> +	cachep->flags |= SLAB_DEACTIVATED;

A nit: it can be done from kmemcg_cache_deactivate() instead,
and then you don't have to do it in slab and slub separately.

Since it's not slab- or slub-specific code, it'd be better, IMO,
to put it into slab_common.c.

Thanks!

>  	__kmem_cache_shrink(cachep);
>  }
>  
> diff --git a/mm/slab_common.c b/mm/slab_common.c
> index 146d8eaa639c..85cf0c374303 100644
> --- a/mm/slab_common.c
> +++ b/mm/slab_common.c
> @@ -1533,7 +1533,7 @@ static int memcg_slabinfo_show(struct seq_file *m, void *unused)
>  	struct slabinfo sinfo;
>  
>  	mutex_lock(&slab_mutex);
> -	seq_puts(m, "# <name> <css_id[:dead]> <active_objs> <num_objs>");
> +	seq_puts(m, "# <name> <css_id[:dead|deact]> <active_objs> <num_objs>");
>  	seq_puts(m, " <active_slabs> <num_slabs>\n");
>  	list_for_each_entry(s, &slab_root_caches, root_caches_node) {
>  		/*
> @@ -1544,22 +1544,24 @@ static int memcg_slabinfo_show(struct seq_file *m, void *unused)
>  
>  		memset(&sinfo, 0, sizeof(sinfo));
>  		get_slabinfo(s, &sinfo);
> -		seq_printf(m, "%-17s root      %6lu %6lu %6lu %6lu\n",
> +		seq_printf(m, "%-17s root       %6lu %6lu %6lu %6lu\n",
>  			   cache_name(s), sinfo.active_objs, sinfo.num_objs,
>  			   sinfo.active_slabs, sinfo.num_slabs);
>  
>  		for_each_memcg_cache(c, s) {
>  			struct cgroup_subsys_state *css;
> -			char *dead = "";
> +			char *status = "";
>  
>  			css = &c->memcg_params.memcg->css;
>  			if (!(css->flags & CSS_ONLINE))
> -				dead = ":dead";
> +				status = ":dead";
> +			else if (c->flags & SLAB_DEACTIVATED)
> +				status = ":deact";
>  
>  			memset(&sinfo, 0, sizeof(sinfo));
>  			get_slabinfo(c, &sinfo);
> -			seq_printf(m, "%-17s %4d%5s %6lu %6lu %6lu %6lu\n",
> -				   cache_name(c), css->id, dead,
> +			seq_printf(m, "%-17s %4d%-6s %6lu %6lu %6lu %6lu\n",
> +				   cache_name(c), css->id, status,
>  				   sinfo.active_objs, sinfo.num_objs,
>  				   sinfo.active_slabs, sinfo.num_slabs);
>  		}
> diff --git a/mm/slub.c b/mm/slub.c
> index a384228ff6d3..c965b4413658 100644
> --- a/mm/slub.c
> +++ b/mm/slub.c
> @@ -4057,6 +4057,7 @@ void __kmemcg_cache_deactivate(struct kmem_cache *s)
>  	 */
>  	slub_set_cpu_partial(s, 0);
>  	s->min_partial = 0;
> +	s->flags |= SLAB_DEACTIVATED;
>  }
>  #endif	/* CONFIG_MEMCG */
>  
> -- 
> 2.18.1
>
Waiman Long June 27, 2019, 6:45 p.m. UTC | #3
On 6/26/19 3:58 PM, Roman Gushchin wrote:
> On Fri, Jun 21, 2019 at 01:30:05PM -0400, Waiman Long wrote:
>> With Roman's kmem cache reparent patch, multiple kmem caches of the same
>> type can be seen attached to the same memcg id. All of them, except
>> maybe one, are reparent'ed kmem caches. It can be useful to tag those
>> reparented caches by adding a new slab flag "SLAB_DEACTIVATED" to those
>> kmem caches that will be reparent'ed if it cannot be destroyed completely.
>>
>> For the reparent'ed memcg kmem caches, the tag ":deact" will now be
>> shown in <debugfs>/memcg_slabinfo.
>>
>> Signed-off-by: Waiman Long <longman@redhat.com>
> Hi Waiman!
>
> Sorry for the late reply. The patch overall looks good to me,
> except one nit. Please feel free to use my ack:
> Acked-by: Roman Gushchin <guro@fb.com>
>
>> ---
>>  include/linux/slab.h |  4 ++++
>>  mm/slab.c            |  1 +
>>  mm/slab_common.c     | 14 ++++++++------
>>  mm/slub.c            |  1 +
>>  4 files changed, 14 insertions(+), 6 deletions(-)
>>
>> diff --git a/include/linux/slab.h b/include/linux/slab.h
>> index fecf40b7be69..19ab1380f875 100644
>> --- a/include/linux/slab.h
>> +++ b/include/linux/slab.h
>> @@ -116,6 +116,10 @@
>>  /* Objects are reclaimable */
>>  #define SLAB_RECLAIM_ACCOUNT	((slab_flags_t __force)0x00020000U)
>>  #define SLAB_TEMPORARY		SLAB_RECLAIM_ACCOUNT	/* Objects are short-lived */
>> +
>> +/* Slab deactivation flag */
>> +#define SLAB_DEACTIVATED	((slab_flags_t __force)0x10000000U)
>> +
>>  /*
>>   * ZERO_SIZE_PTR will be returned for zero sized kmalloc requests.
>>   *
>> diff --git a/mm/slab.c b/mm/slab.c
>> index a2e93adf1df0..e8c7743fc283 100644
>> --- a/mm/slab.c
>> +++ b/mm/slab.c
>> @@ -2245,6 +2245,7 @@ int __kmem_cache_shrink(struct kmem_cache *cachep)
>>  #ifdef CONFIG_MEMCG
>>  void __kmemcg_cache_deactivate(struct kmem_cache *cachep)
>>  {
>> +	cachep->flags |= SLAB_DEACTIVATED;
> A nit: it can be done from kmemcg_cache_deactivate() instead,
> and then you don't have to do it in slab and slub separately.
>
> Since it's not slab- or slub-specific code, it'd be better, IMO,
> to put it into slab_common.c.

Thanks for the suggestion.

You are right. It will be cleaner to set the flag in
kmemcg_cache_deactivate(). I have just sent out a v2 patch to do that.

Cheers,
Longman
diff mbox series

Patch

diff --git a/include/linux/slab.h b/include/linux/slab.h
index fecf40b7be69..19ab1380f875 100644
--- a/include/linux/slab.h
+++ b/include/linux/slab.h
@@ -116,6 +116,10 @@ 
 /* Objects are reclaimable */
 #define SLAB_RECLAIM_ACCOUNT	((slab_flags_t __force)0x00020000U)
 #define SLAB_TEMPORARY		SLAB_RECLAIM_ACCOUNT	/* Objects are short-lived */
+
+/* Slab deactivation flag */
+#define SLAB_DEACTIVATED	((slab_flags_t __force)0x10000000U)
+
 /*
  * ZERO_SIZE_PTR will be returned for zero sized kmalloc requests.
  *
diff --git a/mm/slab.c b/mm/slab.c
index a2e93adf1df0..e8c7743fc283 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -2245,6 +2245,7 @@  int __kmem_cache_shrink(struct kmem_cache *cachep)
 #ifdef CONFIG_MEMCG
 void __kmemcg_cache_deactivate(struct kmem_cache *cachep)
 {
+	cachep->flags |= SLAB_DEACTIVATED;
 	__kmem_cache_shrink(cachep);
 }
 
diff --git a/mm/slab_common.c b/mm/slab_common.c
index 146d8eaa639c..85cf0c374303 100644
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -1533,7 +1533,7 @@  static int memcg_slabinfo_show(struct seq_file *m, void *unused)
 	struct slabinfo sinfo;
 
 	mutex_lock(&slab_mutex);
-	seq_puts(m, "# <name> <css_id[:dead]> <active_objs> <num_objs>");
+	seq_puts(m, "# <name> <css_id[:dead|deact]> <active_objs> <num_objs>");
 	seq_puts(m, " <active_slabs> <num_slabs>\n");
 	list_for_each_entry(s, &slab_root_caches, root_caches_node) {
 		/*
@@ -1544,22 +1544,24 @@  static int memcg_slabinfo_show(struct seq_file *m, void *unused)
 
 		memset(&sinfo, 0, sizeof(sinfo));
 		get_slabinfo(s, &sinfo);
-		seq_printf(m, "%-17s root      %6lu %6lu %6lu %6lu\n",
+		seq_printf(m, "%-17s root       %6lu %6lu %6lu %6lu\n",
 			   cache_name(s), sinfo.active_objs, sinfo.num_objs,
 			   sinfo.active_slabs, sinfo.num_slabs);
 
 		for_each_memcg_cache(c, s) {
 			struct cgroup_subsys_state *css;
-			char *dead = "";
+			char *status = "";
 
 			css = &c->memcg_params.memcg->css;
 			if (!(css->flags & CSS_ONLINE))
-				dead = ":dead";
+				status = ":dead";
+			else if (c->flags & SLAB_DEACTIVATED)
+				status = ":deact";
 
 			memset(&sinfo, 0, sizeof(sinfo));
 			get_slabinfo(c, &sinfo);
-			seq_printf(m, "%-17s %4d%5s %6lu %6lu %6lu %6lu\n",
-				   cache_name(c), css->id, dead,
+			seq_printf(m, "%-17s %4d%-6s %6lu %6lu %6lu %6lu\n",
+				   cache_name(c), css->id, status,
 				   sinfo.active_objs, sinfo.num_objs,
 				   sinfo.active_slabs, sinfo.num_slabs);
 		}
diff --git a/mm/slub.c b/mm/slub.c
index a384228ff6d3..c965b4413658 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -4057,6 +4057,7 @@  void __kmemcg_cache_deactivate(struct kmem_cache *s)
 	 */
 	slub_set_cpu_partial(s, 0);
 	s->min_partial = 0;
+	s->flags |= SLAB_DEACTIVATED;
 }
 #endif	/* CONFIG_MEMCG */