linux-mm.kvack.org archive mirror
 help / color / mirror / Atom feed
From: Roman Gushchin <guro@fb.com>
To: Jann Horn <jannh@google.com>
Cc: Christoph Lameter <cl@linux.com>,
	Pekka Enberg <penberg@kernel.org>,
	David Rientjes <rientjes@google.com>,
	Joonsoo Kim <iamjoonsoo.kim@lge.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	Linux-MM <linux-mm@kvack.org>,
	kernel list <linux-kernel@vger.kernel.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
	Johannes Weiner <hannes@cmpxchg.org>,
	Shakeel Butt <shakeelb@google.com>,
	Suren Baghdasaryan <surenb@google.com>,
	Minchan Kim <minchan@kernel.org>
Subject: Re: SLUB: percpu partial object count is highly inaccurate, causing some memory wastage and maybe also worse tail latencies?
Date: Mon, 11 Jan 2021 16:27:20 -0800	[thread overview]
Message-ID: <20210112002720.GA35320@carbon.dhcp.thefacebook.com> (raw)
In-Reply-To: <CAG48ez2Qx5K1Cab-m8BdSibp6wLTip6ro4=-umR7BLsEgjEYzA@mail.gmail.com>

On Tue, Jan 12, 2021 at 12:12:47AM +0100, Jann Horn wrote:
> [This is not something I intend to work on myself. But since I
> stumbled over this issue, I figured I should at least document/report
> it, in case anyone is willing to pick it up.]

Hi, Jann!

Thank you very much for this report!

It should be less of a problem since 5.9, but still on a machine with
many CPUs a non-trivial amount of memory is wasted.

I'll definitely take a look.

Thanks!


  reply	other threads:[~2021-01-12  0:27 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-01-11 23:12 SLUB: percpu partial object count is highly inaccurate, causing some memory wastage and maybe also worse tail latencies? Jann Horn
2021-01-12  0:27 ` Roman Gushchin [this message]
2021-01-12 16:35 ` Christoph Lameter
2021-01-14  9:27   ` Vlastimil Babka
2021-01-18 11:03     ` Michal Hocko
2021-01-18 15:46       ` Christoph Lameter
2021-01-18 16:07         ` Michal Hocko
2021-01-13 19:14 ` Vlastimil Babka
2021-01-13 22:37   ` Jann Horn
2021-01-14  9:04     ` Christoph Lameter
2021-01-21 17:21 ` Vlastimil Babka
2021-01-21 17:21   ` [RFC 1/2] mm, vmscan: add priority field to struct shrink_control Vlastimil Babka
2021-01-21 17:21     ` [RFC 2/2] mm, slub: add shrinker to reclaim cached slabs Vlastimil Babka
2021-01-22  0:48       ` Roman Gushchin
2021-01-26 12:06         ` Vlastimil Babka

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=20210112002720.GA35320@carbon.dhcp.thefacebook.com \
    --to=guro@fb.com \
    --cc=akpm@linux-foundation.org \
    --cc=bigeasy@linutronix.de \
    --cc=cl@linux.com \
    --cc=hannes@cmpxchg.org \
    --cc=iamjoonsoo.kim@lge.com \
    --cc=jannh@google.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=minchan@kernel.org \
    --cc=penberg@kernel.org \
    --cc=rientjes@google.com \
    --cc=shakeelb@google.com \
    --cc=surenb@google.com \
    --cc=tglx@linutronix.de \
    /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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).