Let's use generic slab_start/next/stop for showing memcg caches info. In contrast to the current implementation, this will work even if all memcg caches' info doesn't fit into a seq buffer (a page), plus it simply looks neater.
Actually, the main reason I do this isn't mere cleanup. I'm going to zap the memcg_slab_caches list, because I find it useless provided we have the slab_caches list, and this patch is a step in this direction. It should be noted that before this patch an attempt to read memory.kmem.slabinfo of a cgroup that doesn't have kmem limit set resulted in -EIO, while after this patch it will silently show nothing except the header, but I don't think it will frustrate anyone. Signed-off-by: Vladimir Davydov <[email protected]> --- include/linux/slab.h | 4 ---- mm/memcontrol.c | 25 ++++--------------------- mm/slab.h | 1 + mm/slab_common.c | 25 +++++++++++++++++++------ 4 files changed, 24 insertions(+), 31 deletions(-) diff --git a/include/linux/slab.h b/include/linux/slab.h index c265bec6a57d..8a2457d42fc8 100644 --- a/include/linux/slab.h +++ b/include/linux/slab.h @@ -513,10 +513,6 @@ struct memcg_cache_params { int memcg_update_all_caches(int num_memcgs); -struct seq_file; -int cache_show(struct kmem_cache *s, struct seq_file *m); -void print_slabinfo_header(struct seq_file *m); - /** * kmalloc_array - allocate memory for an array. * @n: number of elements. diff --git a/mm/memcontrol.c b/mm/memcontrol.c index c50176429fa3..54d4305ba1dd 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -2460,26 +2460,6 @@ static struct kmem_cache *memcg_params_to_cache(struct memcg_cache_params *p) return cache_from_memcg_idx(cachep, memcg_cache_id(p->memcg)); } -#ifdef CONFIG_SLABINFO -static int mem_cgroup_slabinfo_read(struct seq_file *m, void *v) -{ - struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m)); - struct memcg_cache_params *params; - - if (!memcg_kmem_is_active(memcg)) - return -EIO; - - print_slabinfo_header(m); - - mutex_lock(&memcg_slab_mutex); - list_for_each_entry(params, &memcg->memcg_slab_caches, list) - cache_show(memcg_params_to_cache(params), m); - mutex_unlock(&memcg_slab_mutex); - - return 0; -} -#endif - static int memcg_charge_kmem(struct mem_cgroup *memcg, gfp_t gfp, unsigned long nr_pages) { @@ -4621,7 +4601,10 @@ static struct cftype mem_cgroup_files[] = { #ifdef CONFIG_SLABINFO { .name = "kmem.slabinfo", - .seq_show = mem_cgroup_slabinfo_read, + .seq_start = slab_start, + .seq_next = slab_next, + .seq_stop = slab_stop, + .seq_show = memcg_slab_show, }, #endif #endif diff --git a/mm/slab.h b/mm/slab.h index 53a55c70c409..3347fd77f7be 100644 --- a/mm/slab.h +++ b/mm/slab.h @@ -360,5 +360,6 @@ static inline struct kmem_cache_node *get_node(struct kmem_cache *s, int node) void *slab_start(struct seq_file *m, loff_t *pos); void *slab_next(struct seq_file *m, void *p, loff_t *pos); void slab_stop(struct seq_file *m, void *p); +int memcg_slab_show(struct seq_file *m, void *p); #endif /* MM_SLAB_H */ diff --git a/mm/slab_common.c b/mm/slab_common.c index d8b266750985..d5e9e050a3ec 100644 --- a/mm/slab_common.c +++ b/mm/slab_common.c @@ -807,7 +807,7 @@ EXPORT_SYMBOL(kmalloc_order_trace); #define SLABINFO_RIGHTS S_IRUSR #endif -void print_slabinfo_header(struct seq_file *m) +static void print_slabinfo_header(struct seq_file *m) { /* * Output format version, so at least we can change it @@ -872,7 +872,7 @@ memcg_accumulate_slabinfo(struct kmem_cache *s, struct slabinfo *info) } } -int cache_show(struct kmem_cache *s, struct seq_file *m) +static void cache_show(struct kmem_cache *s, struct seq_file *m) { struct slabinfo sinfo; @@ -891,7 +891,6 @@ int cache_show(struct kmem_cache *s, struct seq_file *m) sinfo.active_slabs, sinfo.num_slabs, sinfo.shared_avail); slabinfo_show_stats(m, s); seq_putc(m, '\n'); - return 0; } static int slab_show(struct seq_file *m, void *p) @@ -900,10 +899,24 @@ static int slab_show(struct seq_file *m, void *p) if (p == slab_caches.next) print_slabinfo_header(m); - if (!is_root_cache(s)) - return 0; - return cache_show(s, m); + if (is_root_cache(s)) + cache_show(s, m); + return 0; +} + +#ifdef CONFIG_MEMCG_KMEM +int memcg_slab_show(struct seq_file *m, void *p) +{ + struct kmem_cache *s = list_entry(p, struct kmem_cache, list); + struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m)); + + if (p == slab_caches.next) + print_slabinfo_header(m); + if (!is_root_cache(s) && s->memcg_params->memcg == memcg) + cache_show(s, m); + return 0; } +#endif /* * slabinfo_op - iterator that generates /proc/slabinfo -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
