From: Roman Gushchin <guro@fb.com>
To: Vlastimil Babka <vbabka@suse.cz>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Christoph Lameter <cl@linux.com>,
Johannes Weiner <hannes@cmpxchg.org>,
Michal Hocko <mhocko@kernel.org>,
Shakeel Butt <shakeelb@google.com>, <linux-mm@kvack.org>,
<kernel-team@fb.com>, <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v4 10/19] mm: memcg/slab: deprecate memory.kmem.slabinfo
Date: Wed, 27 May 2020 09:28:08 -0700 [thread overview]
Message-ID: <20200527162808.GB396660@carbon.dhcp.thefacebook.com> (raw)
In-Reply-To: <2dc94375-2ac6-9dd7-64e8-6e66aeb3a662@suse.cz>
On Wed, May 27, 2020 at 05:54:50PM +0200, Vlastimil Babka wrote:
> On 5/26/20 11:42 PM, Roman Gushchin wrote:
> > 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/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: Roman Gushchin <guro@fb.com>
>
> Also there was a
> Acked-by: Johannes Weiner <hannes@cmpxchg.org>
> for this patch.
> And here's mine:
> Acked-by: Vlastimil Babka <vbabka@suse.cz>
Thanks!
>
> Of course this depends on whether we break somebody's workflow and they complain.
We've discussed it a bit around RFC/v1. I hope nobody uses it for anything
except debug purposes, where dragon + bpf can be as good or better.
And actually it is what it is: there are no more per-memcg kmem caches,
so there is nothing to display.
next prev parent reply other threads:[~2020-05-27 16:28 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-26 21:42 [PATCH v4 00/19] The new cgroup slab memory controller Roman Gushchin
2020-05-26 21:42 ` [PATCH v4 01/19] mm: memcg: factor out memcg- and lruvec-level changes out of __mod_lruvec_state() Roman Gushchin
2020-05-26 21:42 ` [PATCH v4 02/19] mm: memcg: prepare for byte-sized vmstat items Roman Gushchin
2020-05-26 21:42 ` [PATCH v4 03/19] mm: memcg: convert vmstat slab counters to bytes Roman Gushchin
2020-05-27 11:43 ` Vlastimil Babka
2020-05-27 16:25 ` Roman Gushchin
2020-05-26 21:42 ` [PATCH v4 04/19] mm: slub: implement SLUB version of obj_to_index() Roman Gushchin
2020-05-27 19:44 ` Johannes Weiner
2020-05-26 21:42 ` [PATCH v4 05/19] mm: memcontrol: decouple reference counting from page accounting Roman Gushchin
2020-05-26 21:42 ` [PATCH v4 06/19] mm: memcg/slab: obj_cgroup API Roman Gushchin
2020-05-27 19:56 ` Johannes Weiner
2020-05-27 20:03 ` Roman Gushchin
2020-05-26 21:42 ` [PATCH v4 07/19] mm: memcg/slab: allocate obj_cgroups for non-root slab pages Roman Gushchin
2020-05-26 21:42 ` [PATCH v4 08/19] mm: memcg/slab: save obj_cgroup for non-root slab objects Roman Gushchin
2020-05-26 21:42 ` [PATCH v4 09/19] mm: memcg/slab: charge individual slab objects instead of pages Roman Gushchin
2020-05-26 21:42 ` [PATCH v4 10/19] mm: memcg/slab: deprecate memory.kmem.slabinfo Roman Gushchin
2020-05-27 15:54 ` Vlastimil Babka
2020-05-27 16:28 ` Roman Gushchin [this message]
2020-05-26 21:42 ` [PATCH v4 11/19] mm: memcg/slab: move memcg_kmem_bypass() to memcontrol.h Roman Gushchin
2020-05-26 21:42 ` [PATCH v4 12/19] mm: memcg/slab: use a single set of kmem_caches for all accounted allocations Roman Gushchin
2020-05-27 16:01 ` Vlastimil Babka
2020-05-27 16:29 ` Roman Gushchin
2020-05-26 21:42 ` [PATCH v4 13/19] mm: memcg/slab: simplify memcg cache creation Roman Gushchin
2020-05-26 21:42 ` [PATCH v4 14/19] mm: memcg/slab: remove memcg_kmem_get_cache() Roman Gushchin
2020-05-26 21:42 ` [PATCH v4 15/19] mm: memcg/slab: deprecate slab_root_caches Roman Gushchin
2020-05-26 21:42 ` [PATCH v4 16/19] mm: memcg/slab: remove redundant check in memcg_accumulate_slabinfo() Roman Gushchin
2020-05-26 21:42 ` [PATCH v4 17/19] mm: memcg/slab: use a single set of kmem_caches for all allocations Roman Gushchin
2020-05-26 21:42 ` [PATCH v4 18/19] kselftests: cgroup: add kernel memory accounting tests Roman Gushchin
2020-05-26 21:42 ` [PATCH v4 19/19] tools/cgroup: add memcg_slabinfo.py tool Roman Gushchin
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