lkml.org 
[lkml]   [2012]   [Apr]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH 11/23] slub: consider a memcg parameter in kmem_create_cache
    (2012/04/21 6:57), Glauber Costa wrote:

    > Allow a memcg parameter to be passed during cache creation.
    > The slub allocator will only merge caches that belong to
    > the same memcg.
    >
    > Default function is created as a wrapper, passing NULL
    > to the memcg version. We only merge caches that belong
    > to the same memcg.
    >
    >>From the memcontrol.c side, 3 helper functions are created:
    >
    > 1) memcg_css_id: because slub needs a unique cache name
    > for sysfs. Since this is visible, but not the canonical
    > location for slab data, the cache name is not used, the
    > css_id should suffice.
    >
    > 2) mem_cgroup_register_cache: is responsible for assigning
    > a unique index to each cache, and other general purpose
    > setup. The index is only assigned for the root caches. All
    > others are assigned index == -1.
    >
    > 3) mem_cgroup_release_cache: can be called from the root cache
    > destruction, and will release the index for other caches.
    >
    > This index mechanism was developed by Suleiman Souhlal.
    >
    > Signed-off-by: Glauber Costa <glommer@parallels.com>
    > CC: Christoph Lameter <cl@linux.com>
    > CC: Pekka Enberg <penberg@cs.helsinki.fi>
    > CC: Michal Hocko <mhocko@suse.cz>
    > CC: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
    > CC: Johannes Weiner <hannes@cmpxchg.org>
    > CC: Suleiman Souhlal <suleiman@google.com>
    > ---
    > include/linux/memcontrol.h | 14 ++++++++++++++
    > include/linux/slab.h | 6 ++++++
    > mm/memcontrol.c | 29 +++++++++++++++++++++++++++++
    > mm/slub.c | 31 +++++++++++++++++++++++++++----
    > 4 files changed, 76 insertions(+), 4 deletions(-)
    >
    > diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
    > index f94efd2..99e14b9 100644
    > --- a/include/linux/memcontrol.h
    > +++ b/include/linux/memcontrol.h
    > @@ -26,6 +26,7 @@ struct mem_cgroup;
    > struct page_cgroup;
    > struct page;
    > struct mm_struct;
    > +struct kmem_cache;
    >
    > /* Stats that can be updated by kernel. */
    > enum mem_cgroup_page_stat_item {
    > @@ -440,7 +441,20 @@ struct sock;
    > #ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
    > void sock_update_memcg(struct sock *sk);
    > void sock_release_memcg(struct sock *sk);
    > +int memcg_css_id(struct mem_cgroup *memcg);
    > +void mem_cgroup_register_cache(struct mem_cgroup *memcg,
    > + struct kmem_cache *s);
    > +void mem_cgroup_release_cache(struct kmem_cache *cachep);
    > #else
    > +static inline void mem_cgroup_register_cache(struct mem_cgroup *memcg,
    > + struct kmem_cache *s)
    > +{
    > +}
    > +
    > +static inline void mem_cgroup_release_cache(struct kmem_cache *cachep)
    > +{
    > +}
    > +
    > static inline void sock_update_memcg(struct sock *sk)
    > {
    > }
    > diff --git a/include/linux/slab.h b/include/linux/slab.h
    > index a5127e1..c7a7e05 100644
    > --- a/include/linux/slab.h
    > +++ b/include/linux/slab.h
    > @@ -321,6 +321,12 @@ extern void *__kmalloc_track_caller(size_t, gfp_t, unsigned long);
    > __kmalloc(size, flags)
    > #endif /* DEBUG_SLAB */
    >
    > +#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
    > +#define MAX_KMEM_CACHE_TYPES 400
    > +#else
    > +#define MAX_KMEM_CACHE_TYPES 0
    > +#endif /* CONFIG_CGROUP_MEM_RES_CTLR_KMEM */
    > +


    why 400 ?


    > #ifdef CONFIG_NUMA
    > /*
    > * kmalloc_node_track_caller is a special version of kmalloc_node that
    > diff --git a/mm/memcontrol.c b/mm/memcontrol.c
    > index 36f1e6b..0015ed0 100644
    > --- a/mm/memcontrol.c
    > +++ b/mm/memcontrol.c
    > @@ -323,6 +323,11 @@ struct mem_cgroup {
    > #endif
    > };
    >
    > +int memcg_css_id(struct mem_cgroup *memcg)
    > +{
    > + return css_id(&memcg->css);
    > +}
    > +
    > /* Stuffs for move charges at task migration. */
    > /*
    > * Types of charges to be moved. "move_charge_at_immitgrate" is treated as a
    > @@ -461,6 +466,30 @@ struct cg_proto *tcp_proto_cgroup(struct mem_cgroup *memcg)
    > }
    > EXPORT_SYMBOL(tcp_proto_cgroup);
    > #endif /* CONFIG_INET */
    > +
    > +/* Bitmap used for allocating the cache id numbers. */
    > +static DECLARE_BITMAP(cache_types, MAX_KMEM_CACHE_TYPES);
    > +
    > +void mem_cgroup_register_cache(struct mem_cgroup *memcg,
    > + struct kmem_cache *cachep)
    > +{
    > + int id = -1;
    > +
    > + cachep->memcg_params.memcg = memcg;
    > +
    > + if (!memcg) {
    > + id = find_first_zero_bit(cache_types, MAX_KMEM_CACHE_TYPES);
    > + BUG_ON(id < 0 || id >= MAX_KMEM_CACHE_TYPES);
    > + __set_bit(id, cache_types);


    No lock here ? you need find_first_zero_bit_and_set_atomic() or some.
    Rather than that, I think you can use lib/idr.c::ida_simple_get().

    > + } else
    > + INIT_LIST_HEAD(&cachep->memcg_params.destroyed_list);
    > + cachep->memcg_params.id = id;
    > +}
    > +
    > +void mem_cgroup_release_cache(struct kmem_cache *cachep)
    > +{
    > + __clear_bit(cachep->memcg_params.id, cache_types);
    > +}
    > #endif /* CONFIG_CGROUP_MEM_RES_CTLR_KMEM */
    >
    > static void drain_all_stock_async(struct mem_cgroup *memcg);
    > diff --git a/mm/slub.c b/mm/slub.c
    > index 2652e7c..86e40cc 100644
    > --- a/mm/slub.c
    > +++ b/mm/slub.c
    > @@ -32,6 +32,7 @@
    > #include <linux/prefetch.h>
    >
    > #include <trace/events/kmem.h>
    > +#include <linux/memcontrol.h>
    >
    > /*
    > * Lock order:
    > @@ -3880,7 +3881,7 @@ static int slab_unmergeable(struct kmem_cache *s)
    > return 0;
    > }
    >
    > -static struct kmem_cache *find_mergeable(size_t size,
    > +static struct kmem_cache *find_mergeable(struct mem_cgroup *memcg, size_t size,
    > size_t align, unsigned long flags, const char *name,
    > void (*ctor)(void *))
    > {
    > @@ -3916,21 +3917,29 @@ static struct kmem_cache *find_mergeable(size_t size,
    > if (s->size - size >= sizeof(void *))
    > continue;
    >
    > + if (memcg && s->memcg_params.memcg != memcg)
    > + continue;
    > +
    > return s;
    > }
    > return NULL;
    > }
    >
    > -struct kmem_cache *kmem_cache_create(const char *name, size_t size,
    > - size_t align, unsigned long flags, void (*ctor)(void *))
    > +struct kmem_cache *
    > +kmem_cache_create_memcg(struct mem_cgroup *memcg, const char *name, size_t size,
    > + size_t align, unsigned long flags, void (*ctor)(void *))
    > {
    > struct kmem_cache *s;
    >
    > if (WARN_ON(!name))
    > return NULL;
    >
    > +#ifndef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
    > + WARN_ON(memcg != NULL);
    > +#endif


    I'm sorry what's is this warning for ?


    > @@ -5265,6 +5283,11 @@ static char *create_unique_id(struct kmem_cache *s)
    > if (p != name + 1)
    > *p++ = '-';
    > p += sprintf(p, "%07d", s->size);
    > +
    > +#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
    > + if (s->memcg_params.memcg)
    > + p += sprintf(p, "-%08d", memcg_css_id(s->memcg_params.memcg));
    > +#endif
    > BUG_ON(p > name + ID_STR_LENGTH - 1);
    > return name;
    > }


    So, you use 'id' in user interface. Should we provide 'id' as memory.id file ?

    Thanks,
    -Kame



    \
     
     \ /
      Last update: 2012-04-25 03:43    [W:0.040 / U:30.200 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site