All of lore.kernel.org
 help / color / mirror / Atom feed
From: Shakeel Butt <shakeelb@google.com>
To: Waiman Long <longman@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>,
	Michal Hocko <mhocko@kernel.org>,
	Vladimir Davydov <vdavydov.dev@gmail.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	Tejun Heo <tj@kernel.org>, Christoph Lameter <cl@linux.com>,
	Pekka Enberg <penberg@kernel.org>,
	David Rientjes <rientjes@google.com>,
	Joonsoo Kim <iamjoonsoo.kim@lge.com>,
	Vlastimil Babka <vbabka@suse.cz>, Roman Gushchin <guro@fb.com>,
	LKML <linux-kernel@vger.kernel.org>,
	Cgroups <cgroups@vger.kernel.org>, Linux MM <linux-mm@kvack.org>,
	Muchun Song <songmuchun@bytedance.com>,
	Alex Shi <alex.shi@linux.alibaba.com>,
	Chris Down <chris@chrisdown.name>,
	Yafang Shao <laoar.shao@gmail.com>,
	Wei Yang <richard.weiyang@gmail.com>,
	Masayoshi Mizuma <msys.mizuma@gmail.com>,
	Xing Zhengjun <zhengjun.xing@linux.intel.com>
Subject: Re: [PATCH v2 3/5] mm/memcg: Cache vmstat data in percpu memcg_stock_pcp
Date: Mon, 12 Apr 2021 16:03:17 -0700	[thread overview]
Message-ID: <CALvZod7hBvbnF3G_Hxbu3Xmfzdip_BGAh0Nr86vvN2d9xBTaSg@mail.gmail.com> (raw)
In-Reply-To: <20210412225503.15119-4-longman@redhat.com>

On Mon, Apr 12, 2021 at 3:55 PM Waiman Long <longman@redhat.com> wrote:
>
> Before the new slab memory controller with per object byte charging,
> charging and vmstat data update happen only when new slab pages are
> allocated or freed. Now they are done with every kmem_cache_alloc()
> and kmem_cache_free(). This causes additional overhead for workloads
> that generate a lot of alloc and free calls.
>
> The memcg_stock_pcp is used to cache byte charge for a specific
> obj_cgroup to reduce that overhead. To further reducing it, this patch
> makes the vmstat data cached in the memcg_stock_pcp structure as well
> until it accumulates a page size worth of update or when other cached
> data change.
>
> On a 2-socket Cascade Lake server with instrumentation enabled and this
> patch applied, it was found that about 17% (946796 out of 5515184) of the
> time when __mod_obj_stock_state() is called leads to an actual call to
> mod_objcg_state() after initial boot. When doing parallel kernel build,
> the figure was about 16% (21894614 out of 139780628). So caching the
> vmstat data reduces the number of calls to mod_objcg_state() by more
> than 80%.
>
> Signed-off-by: Waiman Long <longman@redhat.com>

Reviewed-by: Shakeel Butt <shakeelb@google.com>

WARNING: multiple messages have this Message-ID (diff)
From: Shakeel Butt <shakeelb-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
To: Waiman Long <longman-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
Cc: Johannes Weiner <hannes-druUgvl0LCNAfugRpC6u6w@public.gmane.org>,
	Michal Hocko <mhocko-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>,
	Vladimir Davydov
	<vdavydov.dev-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>,
	Andrew Morton
	<akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>,
	Tejun Heo <tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>,
	Christoph Lameter <cl-vYTEC60ixJUAvxtiuMwx3w@public.gmane.org>,
	Pekka Enberg <penberg-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>,
	David Rientjes <rientjes-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>,
	Joonsoo Kim <iamjoonsoo.kim-Hm3cg6mZ9cc@public.gmane.org>,
	Vlastimil Babka <vbabka-AlSwsSmVLrQ@public.gmane.org>,
	Roman Gushchin <guro-b10kYP2dOMg@public.gmane.org>,
	LKML <linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
	Cgroups <cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
	Linux MM <linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org>,
	Muchun Song <songmuchun-EC8Uxl6Npydl57MIdRCFDg@public.gmane.org>,
	Alex Shi
	<alex.shi-KPsoFbNs7GizrGE5bRqYAgC/G2K4zDHf@public.gmane.org>,
	Chris Down <chris-6Bi1550iOqEnzZ6mRAm98g@public.gmane.org>,
	Yafang Shao <laoar.shao-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>,
	Wei Yang
	<richard.weiyang-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>,
	Masayoshi Mizuma
	<msys.mizuma-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>,
	Xing Zhengjun <zhengjun.xing@linu>
Subject: Re: [PATCH v2 3/5] mm/memcg: Cache vmstat data in percpu memcg_stock_pcp
Date: Mon, 12 Apr 2021 16:03:17 -0700	[thread overview]
Message-ID: <CALvZod7hBvbnF3G_Hxbu3Xmfzdip_BGAh0Nr86vvN2d9xBTaSg@mail.gmail.com> (raw)
In-Reply-To: <20210412225503.15119-4-longman-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>

On Mon, Apr 12, 2021 at 3:55 PM Waiman Long <longman-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> wrote:
>
> Before the new slab memory controller with per object byte charging,
> charging and vmstat data update happen only when new slab pages are
> allocated or freed. Now they are done with every kmem_cache_alloc()
> and kmem_cache_free(). This causes additional overhead for workloads
> that generate a lot of alloc and free calls.
>
> The memcg_stock_pcp is used to cache byte charge for a specific
> obj_cgroup to reduce that overhead. To further reducing it, this patch
> makes the vmstat data cached in the memcg_stock_pcp structure as well
> until it accumulates a page size worth of update or when other cached
> data change.
>
> On a 2-socket Cascade Lake server with instrumentation enabled and this
> patch applied, it was found that about 17% (946796 out of 5515184) of the
> time when __mod_obj_stock_state() is called leads to an actual call to
> mod_objcg_state() after initial boot. When doing parallel kernel build,
> the figure was about 16% (21894614 out of 139780628). So caching the
> vmstat data reduces the number of calls to mod_objcg_state() by more
> than 80%.
>
> Signed-off-by: Waiman Long <longman-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>

Reviewed-by: Shakeel Butt <shakeelb-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>

  reply	other threads:[~2021-04-12 23:03 UTC|newest]

Thread overview: 28+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-04-12 22:54 [PATCH v2 0/5] mm/memcg: Reduce kmemcache memory accounting overhead Waiman Long
2021-04-12 22:54 ` Waiman Long
2021-04-12 22:54 ` [PATCH v2 1/5] mm/memcg: Pass both memcg and lruvec to mod_memcg_lruvec_state() Waiman Long
2021-04-12 22:54   ` Waiman Long
2021-04-12 22:55 ` [PATCH v2 2/5] mm/memcg: Introduce obj_cgroup_uncharge_mod_state() Waiman Long
2021-04-12 22:55   ` Waiman Long
2021-04-12 22:55 ` [PATCH v2 3/5] mm/memcg: Cache vmstat data in percpu memcg_stock_pcp Waiman Long
2021-04-12 22:55   ` Waiman Long
2021-04-12 23:03   ` Shakeel Butt [this message]
2021-04-12 23:03     ` Shakeel Butt
2021-04-12 23:03     ` Shakeel Butt
2021-04-13 18:32   ` kernel test robot
2021-04-13 18:32     ` kernel test robot
2021-04-12 22:55 ` [PATCH v2 4/5] mm/memcg: Separate out object stock data into its own struct Waiman Long
2021-04-12 22:55   ` Waiman Long
2021-04-12 23:07   ` Shakeel Butt
2021-04-12 23:07     ` Shakeel Butt
2021-04-12 23:07     ` Shakeel Butt
2021-04-12 22:55 ` [PATCH v2 5/5] mm/memcg: Optimize user context object stock access Waiman Long
2021-04-12 22:55   ` Waiman Long
2021-04-12 23:10   ` Shakeel Butt
2021-04-12 23:10     ` Shakeel Butt
2021-04-12 23:10     ` Shakeel Butt
2021-04-12 23:14     ` Shakeel Butt
2021-04-12 23:14       ` Shakeel Butt
2021-04-12 23:14       ` Shakeel Butt
2021-04-13  1:03     ` Waiman Long
2021-04-13  1:03       ` Waiman Long

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=CALvZod7hBvbnF3G_Hxbu3Xmfzdip_BGAh0Nr86vvN2d9xBTaSg@mail.gmail.com \
    --to=shakeelb@google.com \
    --cc=akpm@linux-foundation.org \
    --cc=alex.shi@linux.alibaba.com \
    --cc=cgroups@vger.kernel.org \
    --cc=chris@chrisdown.name \
    --cc=cl@linux.com \
    --cc=guro@fb.com \
    --cc=hannes@cmpxchg.org \
    --cc=iamjoonsoo.kim@lge.com \
    --cc=laoar.shao@gmail.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=longman@redhat.com \
    --cc=mhocko@kernel.org \
    --cc=msys.mizuma@gmail.com \
    --cc=penberg@kernel.org \
    --cc=richard.weiyang@gmail.com \
    --cc=rientjes@google.com \
    --cc=songmuchun@bytedance.com \
    --cc=tj@kernel.org \
    --cc=vbabka@suse.cz \
    --cc=vdavydov.dev@gmail.com \
    --cc=zhengjun.xing@linux.intel.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.