Commit 4330a26b authored by Roman Gushchin's avatar Roman Gushchin Committed by Linus Torvalds

mm: memcg/slab: deprecate memory.kmem.slabinfo

Deprecate memory.kmem.slabinfo.

An empty file will be presented if corresponding config options are
enabled.

The interface is implementation dependent, isn't present in cgroup v2, and
is generally useful only for core mm debugging purposes.  In other words,
it doesn't provide any value for the absolute majority of users.

A drgn-based replacement can be found in
tools/cgroup/memcg_slabinfo.py.  It does support cgroup v1 and v2,
mimics memory.kmem.slabinfo output and also allows to get any
additional information without a need to recompile the kernel.

If a drgn-based solution is too slow for a task, a bpf-based tracing tool
can be used, which can easily keep track of all slab allocations belonging
to a memory cgroup.
Signed-off-by: default avatarRoman Gushchin <guro@fb.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Reviewed-by: default avatarVlastimil Babka <vbabka@suse.cz>
Reviewed-by: default avatarShakeel Butt <shakeelb@google.com>
Acked-by: default avatarJohannes Weiner <hannes@cmpxchg.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Link: http://lkml.kernel.org/r/20200623174037.3951353-11-guro@fb.comSigned-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent f2fe7b09
...@@ -5114,9 +5114,6 @@ static struct cftype mem_cgroup_legacy_files[] = { ...@@ -5114,9 +5114,6 @@ static struct cftype mem_cgroup_legacy_files[] = {
(defined(CONFIG_SLAB) || defined(CONFIG_SLUB_DEBUG)) (defined(CONFIG_SLAB) || defined(CONFIG_SLUB_DEBUG))
{ {
.name = "kmem.slabinfo", .name = "kmem.slabinfo",
.seq_start = memcg_slab_start,
.seq_next = memcg_slab_next,
.seq_stop = memcg_slab_stop,
.seq_show = memcg_slab_show, .seq_show = memcg_slab_show,
}, },
#endif #endif
......
...@@ -1561,35 +1561,12 @@ void dump_unreclaimable_slab(void) ...@@ -1561,35 +1561,12 @@ void dump_unreclaimable_slab(void)
} }
#if defined(CONFIG_MEMCG_KMEM) #if defined(CONFIG_MEMCG_KMEM)
void *memcg_slab_start(struct seq_file *m, loff_t *pos)
{
struct mem_cgroup *memcg = mem_cgroup_from_seq(m);
mutex_lock(&slab_mutex);
return seq_list_start(&memcg->kmem_caches, *pos);
}
void *memcg_slab_next(struct seq_file *m, void *p, loff_t *pos)
{
struct mem_cgroup *memcg = mem_cgroup_from_seq(m);
return seq_list_next(p, &memcg->kmem_caches, pos);
}
void memcg_slab_stop(struct seq_file *m, void *p)
{
mutex_unlock(&slab_mutex);
}
int memcg_slab_show(struct seq_file *m, void *p) int memcg_slab_show(struct seq_file *m, void *p)
{ {
struct kmem_cache *s = list_entry(p, struct kmem_cache, /*
memcg_params.kmem_caches_node); * Deprecated.
struct mem_cgroup *memcg = mem_cgroup_from_seq(m); * Please, take a look at tools/cgroup/slabinfo.py .
*/
if (p == memcg->kmem_caches.next)
print_slabinfo_header(m);
cache_show(s, m);
return 0; return 0;
} }
#endif #endif
......
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