From: Dave Hansen <dave@linux.vnet.ibm.com>
To: "Peter Schüller" <scode@spotify.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
linux-kernel@vger.kernel.org,
Mattias de Zalenski <zalenski@spotify.com>,
linux-mm@kvack.org
Subject: Re: Sudden and massive page cache eviction
Date: Wed, 24 Nov 2010 09:32:09 -0800 [thread overview]
Message-ID: <1290619929.10586.6.camel@nimitz> (raw)
In-Reply-To: <AANLkTi=mgTHPEYFsryDYnxPa78f-Nr+H7i4+0KPZbxh3@mail.gmail.com>
On Wed, 2010-11-24 at 15:14 +0100, Peter Schüller wrote:
> >> Do you have any large page (hugetlbfs) or other multi-order (> 1 page)
> >> allocations happening in the kernel?
>
> I forgot to address the second part of this question: How would I best
> inspect whether the kernel is doing that?
I found out yesterday how to do it with tracing, but it's not a horribly
simple thing to do in any case. You can watch the entries in slabinfo
and see if any of the ones with sizes over 4096 bytes are getting used
often. You can also watch /proc/buddyinfo and see how often columns
other than the first couple are moving around.
Jumbo ethernet frames would be the most common reason to see these
allocations. It's _probably_ not an issue in your case.
-- Dave
WARNING: multiple messages have this Message-ID (diff)
From: Dave Hansen <dave@linux.vnet.ibm.com>
To: "Peter Schüller" <scode@spotify.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
linux-kernel@vger.kernel.org,
Mattias de Zalenski <zalenski@spotify.com>,
linux-mm@kvack.org
Subject: Re: Sudden and massive page cache eviction
Date: Wed, 24 Nov 2010 09:32:09 -0800 [thread overview]
Message-ID: <1290619929.10586.6.camel@nimitz> (raw)
In-Reply-To: <AANLkTi=mgTHPEYFsryDYnxPa78f-Nr+H7i4+0KPZbxh3@mail.gmail.com>
On Wed, 2010-11-24 at 15:14 +0100, Peter Schuller wrote:
> >> Do you have any large page (hugetlbfs) or other multi-order (> 1 page)
> >> allocations happening in the kernel?
>
> I forgot to address the second part of this question: How would I best
> inspect whether the kernel is doing that?
I found out yesterday how to do it with tracing, but it's not a horribly
simple thing to do in any case. You can watch the entries in slabinfo
and see if any of the ones with sizes over 4096 bytes are getting used
often. You can also watch /proc/buddyinfo and see how often columns
other than the first couple are moving around.
Jumbo ethernet frames would be the most common reason to see these
allocations. It's _probably_ not an issue in your case.
-- Dave
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Fight unfair telecom policy in Canada: sign http://dissolvethecrtc.ca/
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2010-11-24 17:32 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-11-12 16:20 Sudden and massive page cache eviction Peter Schüller
2010-11-23 0:11 ` Andrew Morton
2010-11-23 0:11 ` Andrew Morton
2010-11-23 8:38 ` Dave Hansen
2010-11-23 8:38 ` Dave Hansen
2010-11-23 9:44 ` Peter Schüller
2010-11-23 9:44 ` Peter Schüller
2010-11-23 16:19 ` Dave Hansen
2010-11-23 16:19 ` Dave Hansen
2010-11-24 14:02 ` Peter Schüller
2010-11-24 14:02 ` Peter Schüller
2010-11-24 14:14 ` Peter Schüller
2010-11-24 14:14 ` Peter Schüller
2010-11-24 14:20 ` Pekka Enberg
2010-11-24 14:20 ` Pekka Enberg
2010-11-24 15:32 ` Peter Schüller
2010-11-24 15:32 ` Peter Schüller
2010-11-24 17:46 ` Pekka Enberg
2010-11-24 17:46 ` Pekka Enberg
2010-11-25 1:18 ` Simon Kirby
2010-11-25 1:18 ` Simon Kirby
2010-11-25 15:59 ` Peter Schüller
2010-11-25 15:59 ` Peter Schüller
2010-12-01 6:36 ` Simon Kirby
2010-12-01 6:36 ` Simon Kirby
2010-11-24 17:32 ` Dave Hansen [this message]
2010-11-24 17:32 ` Dave Hansen
2010-11-25 15:33 ` Peter Schüller
2010-11-25 15:33 ` Peter Schüller
2010-12-01 9:15 ` Simon Kirby
2010-12-01 9:15 ` Simon Kirby
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=1290619929.10586.6.camel@nimitz \
--to=dave@linux.vnet.ibm.com \
--cc=akpm@linux-foundation.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=scode@spotify.com \
--cc=zalenski@spotify.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.