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 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.