From: Roman Gushchin <guro@fb.com>
To: Muchun Song <songmuchun@bytedance.com>
Cc: <gregkh@linuxfoundation.org>, <rafael@kernel.org>,
<adobriyan@gmail.com>, <akpm@linux-foundation.org>,
<hannes@cmpxchg.org>, <mhocko@kernel.org>,
<vdavydov.dev@gmail.com>, <hughd@google.com>, <will@kernel.org>,
<rppt@kernel.org>, <tglx@linutronix.de>, <esyr@redhat.com>,
<peterx@redhat.com>, <krisman@collabora.com>, <surenb@google.com>,
<avagin@openvz.org>, <elver@google.com>, <rdunlap@infradead.org>,
<iamjoonsoo.kim@lge.com>, <linux-kernel@vger.kernel.org>,
<linux-fsdevel@vger.kernel.org>, <linux-mm@kvack.org>,
<cgroups@vger.kernel.org>
Subject: Re: [RESEND PATCH v2 09/12] mm: memcontrol: convert vmstat slab counters to bytes
Date: Mon, 7 Dec 2020 12:01:55 -0800 [thread overview]
Message-ID: <20201207200155.GC2238414@carbon.dhcp.thefacebook.com> (raw)
In-Reply-To: <20201207194622.GA2238414@carbon.dhcp.thefacebook.com>
On Mon, Dec 07, 2020 at 11:46:22AM -0800, Roman Gushchin wrote:
> On Sun, Dec 06, 2020 at 06:14:48PM +0800, Muchun Song wrote:
> > the global and per-node counters are stored in pages, however memcg
> > and lruvec counters are stored in bytes. This scheme looks weird.
> > So convert all vmstat slab counters to bytes.
>
> There is a reason for this weird scheme:
> percpu caches (see struct per_cpu_nodestat) are s8, so counting in bytes
> will lead to overfills. Switching to s32 can lead to an increase in
> the cache thrashing, especially on small machines.
JFYI:
I've tried to convert all slab counters to bytes and change those s8 percpu batches to s32
about a year ago. Here is a link to that thread:
https://patchwork.kernel.org/project/linux-mm/patch/20191018002820.307763-3-guro@fb.com/
Thanks!
next prev parent reply other threads:[~2020-12-07 20:02 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-06 10:14 [RESEND PATCH v2 00/12] Convert all vmstat counters to pages or bytes Muchun Song
2020-12-06 10:14 ` [RESEND PATCH v2 01/12] mm: memcontrol: fix NR_ANON_THPS account Muchun Song
2020-12-07 12:52 ` Michal Hocko
2020-12-10 16:00 ` Johannes Weiner
2020-12-10 16:02 ` Johannes Weiner
2020-12-10 16:04 ` Johannes Weiner
2020-12-10 16:56 ` [External] " Muchun Song
2020-12-06 10:14 ` [RESEND PATCH v2 02/12] mm: memcontrol: convert NR_ANON_THPS account to pages Muchun Song
2020-12-10 16:10 ` Johannes Weiner
2020-12-10 17:05 ` [External] " Muchun Song
2020-12-06 10:14 ` [RESEND PATCH v2 03/12] mm: memcontrol: convert NR_FILE_THPS " Muchun Song
2020-12-06 10:14 ` [RESEND PATCH v2 04/12] mm: memcontrol: convert NR_SHMEM_THPS " Muchun Song
2020-12-06 10:14 ` [RESEND PATCH v2 05/12] mm: memcontrol: convert NR_SHMEM_PMDMAPPED " Muchun Song
2020-12-06 10:14 ` [RESEND PATCH v2 06/12] mm: memcontrol: convert NR_FILE_PMDMAPPED " Muchun Song
2020-12-06 10:14 ` [RESEND PATCH v2 07/12] mm: memcontrol: convert kernel stack account to bytes Muchun Song
2020-12-06 10:14 ` [RESEND PATCH v2 08/12] mm: memcontrol: convert NR_KERNEL_SCS_KB " Muchun Song
2020-12-06 10:14 ` [RESEND PATCH v2 09/12] mm: memcontrol: convert vmstat slab counters " Muchun Song
2020-12-07 19:46 ` Roman Gushchin
2020-12-07 20:01 ` Roman Gushchin [this message]
2020-12-08 2:44 ` [External] " Muchun Song
2020-12-06 10:14 ` [RESEND PATCH v2 10/12] mm: memcontrol: scale stat_threshold for byted-sized vmstat Muchun Song
2020-12-06 10:14 ` [RESEND PATCH v2 11/12] mm: memcontrol: make the slab calculation consistent Muchun Song
2020-12-06 10:14 ` [RESEND PATCH v2 12/12] mm: memcontrol: remove {global_}node_page_state_pages Muchun Song
2020-12-07 13:00 ` [RESEND PATCH v2 00/12] Convert all vmstat counters to pages or bytes Michal Hocko
2020-12-07 14:52 ` [External] " Muchun Song
2020-12-07 15:02 ` Michal Hocko
2020-12-07 18:51 ` Randy Dunlap
2020-12-08 2:29 ` Muchun Song
2020-12-07 19:51 ` Roman Gushchin
2020-12-07 20:33 ` Hugh Dickins
2020-12-08 2:42 ` Muchun Song
2020-12-08 2:40 ` Muchun Song
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