From: Roman Gushchin <guro@fb.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Christoph Lameter <cl@linux.com>,
Johannes Weiner <hannes@cmpxchg.org>,
Michal Hocko <mhocko@kernel.org>,
Shakeel Butt <shakeelb@google.com>, <linux-mm@kvack.org>,
Vlastimil Babka <vbabka@suse.cz>, <kernel-team@fb.com>,
<linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v6 17/19] mm: memcg/slab: use a single set of kmem_caches for all allocations
Date: Wed, 17 Jun 2020 17:35:15 -0700 [thread overview]
Message-ID: <20200618003515.GB24694@carbon.DHCP.thefacebook.com> (raw)
In-Reply-To: <20200617163528.a4477749b172c387e01c3996@linux-foundation.org>
On Wed, Jun 17, 2020 at 04:35:28PM -0700, Andrew Morton wrote:
> On Mon, 8 Jun 2020 16:06:52 -0700 Roman Gushchin <guro@fb.com> wrote:
>
> > Instead of having two sets of kmem_caches: one for system-wide and
> > non-accounted allocations and the second one shared by all accounted
> > allocations, we can use just one.
> >
> > The idea is simple: space for obj_cgroup metadata can be allocated
> > on demand and filled only for accounted allocations.
> >
> > It allows to remove a bunch of code which is required to handle
> > kmem_cache clones for accounted allocations. There is no more need
> > to create them, accumulate statistics, propagate attributes, etc.
> > It's a quite significant simplification.
> >
> > Also, because the total number of slab_caches is reduced almost twice
> > (not all kmem_caches have a memcg clone), some additional memory
> > savings are expected. On my devvm it additionally saves about 3.5%
> > of slab memory.
> >
>
> This ran afoul of Vlastimil's "mm, slab/slub: move and improve
> cache_from_obj()"
> (http://lkml.kernel.org/r/20200610163135.17364-10-vbabka@suse.cz). I
> resolved things as below. Not too sure about slab.c's
> cache_from_obj()...
It can actually be as simple as:
static inline struct kmem_cache *cache_from_obj(struct kmem_cache *s, void *x)
{
return s;
}
But I wonder if we need it at all, or maybe we wanna rename it to
something like obj_check_kmem_cache(void *obj, struct kmem_cache *s),
because it has now only debug purposes.
Let me and Vlastimil figure it out and send a follow-up patch.
Your version is definitely correct.
Thanks!
next prev parent reply other threads:[~2020-06-18 0:35 UTC|newest]
Thread overview: 92+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-08 23:06 [PATCH v6 00/19] The new cgroup slab memory controller Roman Gushchin
2020-06-08 23:06 ` [PATCH v6 01/19] mm: memcg: factor out memcg- and lruvec-level changes out of __mod_lruvec_state() Roman Gushchin
2020-06-17 1:52 ` Shakeel Butt
2020-06-17 2:50 ` Roman Gushchin
2020-06-17 2:59 ` Shakeel Butt
2020-06-17 3:19 ` Roman Gushchin
2020-06-08 23:06 ` [PATCH v6 02/19] mm: memcg: prepare for byte-sized vmstat items Roman Gushchin
2020-06-17 2:57 ` Shakeel Butt
2020-06-17 3:19 ` Roman Gushchin
2020-06-17 15:55 ` Shakeel Butt
2020-06-08 23:06 ` [PATCH v6 03/19] mm: memcg: convert vmstat slab counters to bytes Roman Gushchin
2020-06-17 3:03 ` Shakeel Butt
2020-06-08 23:06 ` [PATCH v6 04/19] mm: slub: implement SLUB version of obj_to_index() Roman Gushchin
2020-06-17 3:08 ` Shakeel Butt
2020-06-08 23:06 ` [PATCH v6 05/19] mm: memcontrol: decouple reference counting from page accounting Roman Gushchin
2020-06-18 0:47 ` Shakeel Butt
2020-06-18 14:55 ` Shakeel Butt
2020-06-18 19:51 ` Roman Gushchin
2020-06-19 1:08 ` Roman Gushchin
2020-06-19 1:18 ` Shakeel Butt
2020-06-19 1:31 ` Shakeel Butt
2020-06-08 23:06 ` [PATCH v6 06/19] mm: memcg/slab: obj_cgroup API Roman Gushchin
2020-06-19 15:42 ` Shakeel Butt
2020-06-19 21:38 ` Roman Gushchin
2020-06-19 22:16 ` Shakeel Butt
2020-06-19 22:52 ` Roman Gushchin
2020-06-20 22:50 ` Andrew Morton
2020-06-08 23:06 ` [PATCH v6 07/19] mm: memcg/slab: allocate obj_cgroups for non-root slab pages Roman Gushchin
2020-06-19 16:36 ` Shakeel Butt
2020-06-20 0:25 ` Roman Gushchin
2020-06-20 0:31 ` Shakeel Butt
2020-06-08 23:06 ` [PATCH v6 08/19] mm: memcg/slab: save obj_cgroup for non-root slab objects Roman Gushchin
2020-06-20 0:16 ` Shakeel Butt
2020-06-20 1:19 ` Roman Gushchin
2020-06-08 23:06 ` [PATCH v6 09/19] mm: memcg/slab: charge individual slab objects instead of pages Roman Gushchin
2020-06-20 0:54 ` Shakeel Butt
2020-06-20 1:29 ` Roman Gushchin
2020-06-08 23:06 ` [PATCH v6 10/19] mm: memcg/slab: deprecate memory.kmem.slabinfo Roman Gushchin
2020-06-22 17:12 ` Shakeel Butt
2020-06-22 18:01 ` Roman Gushchin
2020-06-22 18:09 ` Shakeel Butt
2020-06-22 18:25 ` Roman Gushchin
2020-06-22 18:38 ` Shakeel Butt
2020-06-08 23:06 ` [PATCH v6 11/19] mm: memcg/slab: move memcg_kmem_bypass() to memcontrol.h Roman Gushchin
2020-06-20 1:19 ` Shakeel Butt
2020-06-08 23:06 ` [PATCH v6 12/19] mm: memcg/slab: use a single set of kmem_caches for all accounted allocations Roman Gushchin
2020-06-22 16:56 ` Shakeel Butt
2020-06-08 23:06 ` [PATCH v6 13/19] mm: memcg/slab: simplify memcg cache creation Roman Gushchin
2020-06-22 17:29 ` Shakeel Butt
2020-06-22 17:40 ` Roman Gushchin
2020-06-22 18:03 ` Shakeel Butt
2020-06-08 23:06 ` [PATCH v6 14/19] mm: memcg/slab: remove memcg_kmem_get_cache() Roman Gushchin
2020-06-22 18:42 ` Shakeel Butt
2020-06-08 23:06 ` [PATCH v6 15/19] mm: memcg/slab: deprecate slab_root_caches Roman Gushchin
2020-06-22 17:36 ` Shakeel Butt
2020-06-08 23:06 ` [PATCH v6 16/19] mm: memcg/slab: remove redundant check in memcg_accumulate_slabinfo() Roman Gushchin
2020-06-22 17:32 ` Shakeel Butt
2020-06-08 23:06 ` [PATCH v6 17/19] mm: memcg/slab: use a single set of kmem_caches for all allocations Roman Gushchin
2020-06-17 23:35 ` Andrew Morton
2020-06-18 0:35 ` Roman Gushchin [this message]
2020-06-18 7:33 ` Vlastimil Babka
2020-06-18 19:54 ` Roman Gushchin
2020-06-22 19:21 ` Shakeel Butt
2020-06-22 20:37 ` Roman Gushchin
2020-06-22 21:04 ` Shakeel Butt
2020-06-22 21:13 ` Roman Gushchin
2020-06-22 21:28 ` Shakeel Butt
2020-06-22 21:58 ` Roman Gushchin
2020-06-22 22:05 ` Shakeel Butt
2020-06-08 23:06 ` [PATCH v6 18/19] kselftests: cgroup: add kernel memory accounting tests Roman Gushchin
2020-06-17 1:46 ` [PATCH v6 00/19] The new cgroup slab memory controller Shakeel Butt
2020-06-17 2:41 ` Roman Gushchin
2020-06-17 3:05 ` Shakeel Butt
2020-06-17 3:32 ` Roman Gushchin
2020-06-17 11:24 ` Vlastimil Babka
2020-06-17 14:31 ` Mel Gorman
2020-06-20 0:57 ` Roman Gushchin
2020-06-18 1:29 ` Roman Gushchin
2020-06-18 8:43 ` Jesper Dangaard Brouer
2020-06-18 9:31 ` Jesper Dangaard Brouer
2020-06-19 1:30 ` Roman Gushchin
2020-06-19 8:32 ` Jesper Dangaard Brouer
2020-06-19 1:27 ` Roman Gushchin
2020-06-19 9:39 ` Jesper Dangaard Brouer
2020-06-19 18:47 ` Roman Gushchin
2020-06-18 1:18 ` Roman Gushchin
2020-06-18 9:27 ` Mike Rapoport
2020-06-18 20:43 ` Roman Gushchin
2020-06-21 22:57 ` Qian Cai
2020-06-21 23:34 ` Roman Gushchin
2020-06-21 23:53 ` Qian Cai
2020-06-22 3:07 ` Roman Gushchin
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