From: Pekka Enberg <penberg@kernel.org>
To: David Rientjes <rientjes@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
linux-kernel@vger.kernel.org, Christoph Lameter <cl@linux.com>
Subject: Re: [PATCH v2 2/2] SLUB: Mark merged slab caches in /proc/slabinfo
Date: Wed, 15 Sep 2010 00:00:19 +0300 [thread overview]
Message-ID: <4C8FE263.5070101@kernel.org> (raw)
In-Reply-To: <alpine.DEB.2.00.1009141320090.7123@chino.kir.corp.google.com>
On 14.9.2010 23.56, David Rientjes wrote:
>> In my not-so-humble opinion, either the merging needs to go away
>> entirely, or the misleading output needs to be fixed.
> Cache merging may have been advertised as a bigger performance improvement
> than it actually is, and I don't do it in my own slab allocator for other
> reasons, but it does lead to more effective memory use by reducing slab
> fragmentation. On one of my benchmarking servers, over 60% of caches are
> merged and /sys/kernel/slab/.../partial reports roughly the same percent
> of fewer total partial slabs over the system in comparison to
> slub_nomerge.
Last time I checked (and it's been a while), it did reduce _internal
fragmentation_ for the naive "memory used after boot" scenario. I don't
think I ever advertised it as a performance improvement. Dunno if
somebody else did.
Pekka
next prev parent reply other threads:[~2010-09-14 21:00 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-09-14 18:48 [PATCH v2 1/2] SLUB: Fix merged slab cache names Pekka Enberg
2010-09-14 18:48 ` [PATCH v2 2/2] SLUB: Mark merged slab caches in /proc/slabinfo Pekka Enberg
2010-09-14 20:00 ` David Rientjes
2010-09-14 20:05 ` Linus Torvalds
2010-09-14 20:11 ` Pekka Enberg
2010-09-14 20:56 ` Linus Torvalds
2010-09-14 20:56 ` David Rientjes
2010-09-14 21:00 ` Pekka Enberg [this message]
2010-09-15 0:02 ` David Rientjes
2010-09-15 11:16 ` Theodore Tso
2010-09-15 20:33 ` David Rientjes
2010-09-15 22:25 ` Ted Ts'o
2010-09-15 22:53 ` David Rientjes
2010-09-16 17:39 ` Christoph Lameter
2010-09-16 17:49 ` Linus Torvalds
2010-09-16 22:08 ` Tony Luck
2010-09-14 18:59 ` [PATCH v2 1/2] SLUB: Fix merged slab cache names Christoph Lameter
2010-09-14 19:32 ` Pekka Enberg
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=4C8FE263.5070101@kernel.org \
--to=penberg@kernel.org \
--cc=cl@linux.com \
--cc=linux-kernel@vger.kernel.org \
--cc=rientjes@google.com \
--cc=torvalds@linux-foundation.org \
/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