linux-mm.kvack.org archive mirror
 help / color / mirror / Atom feed
From: Simon Jeons <simon.jeons@gmail.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: paul.szabo@sydney.edu.au, dave@linux.vnet.ibm.com,
	695182@bugs.debian.org, linux-kernel@vger.kernel.org,
	linux-mm@kvack.org
Subject: Re: [RFC] Reproducible OOM with partial workaround
Date: Fri, 11 Jan 2013 02:30:07 -0600	[thread overview]
Message-ID: <1357893007.1466.2.camel@kernel.cn.ibm.com> (raw)
In-Reply-To: <20130111000119.8e9bdf5d.akpm@linux-foundation.org>

On Fri, 2013-01-11 at 00:01 -0800, Andrew Morton wrote:
> On Fri, 11 Jan 2013 12:46:15 +1100 paul.szabo@sydney.edu.au wrote:
> 
> > > ... I don't believe 64GB of RAM has _ever_ been booted on a 32-bit
> > > kernel without either violating the ABI (3GB/1GB split) or doing
> > > something that never got merged upstream ...
> > 
> > Sorry to be so contradictory:
> > 
> > psz@como:~$ uname -a
> > Linux como.maths.usyd.edu.au 3.2.32-pk06.10-t01-i386 #1 SMP Sat Jan 5 18:34:25 EST 2013 i686 GNU/Linux
> > psz@como:~$ free -l
> >              total       used       free     shared    buffers     cached
> > Mem:      64446900    4729292   59717608          0      15972     480520
> > Low:        375836     304400      71436
> > High:     64071064    4424892   59646172
> > -/+ buffers/cache:    4232800   60214100
> > Swap:    134217724          0  134217724
> > psz@como:~$ 
> > 
> > (though I would not know about violations).
> > 
> > But OK, I take your point that I should move with the times.
> 
> Check /proc/slabinfo, see if all your lowmem got eaten up by buffer_heads.
> 
> If so, you *may* be able to work around this by setting
> /proc/sys/vm/dirty_ratio really low, so the system keeps a minimum
> amount of dirty pagecache around.  Then, with luck, if we haven't
> broken the buffer_heads_over_limit logic it in the past decade (we
> probably have), the VM should be able to reclaim those buffer_heads.
> 
> Alternatively, use a filesystem which doesn't attach buffer_heads to
> dirty pages.  xfs or btrfs, perhaps.
> 

Hi Andrew,

What's the meaning of attaching buffer_heads to dirty pages?

> --
> 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/ .
> Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>


--
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/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>

  reply	other threads:[~2013-01-11  8:30 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-01-10 21:58 [RFC] Reproducible OOM with partial workaround paul.szabo
2013-01-10 23:12 ` Dave Hansen
2013-01-11  0:46   ` paul.szabo
2013-01-11  1:26     ` Dave Hansen
2013-01-11  1:46       ` paul.szabo
2013-01-11  8:01         ` Andrew Morton
2013-01-11  8:30           ` Simon Jeons [this message]
2013-01-11 11:51           ` paul.szabo
2013-01-11 20:31             ` Andrew Morton
2013-01-12  3:24               ` paul.szabo
2013-01-11 16:04         ` Dave Hansen

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=1357893007.1466.2.camel@kernel.cn.ibm.com \
    --to=simon.jeons@gmail.com \
    --cc=695182@bugs.debian.org \
    --cc=akpm@linux-foundation.org \
    --cc=dave@linux.vnet.ibm.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=paul.szabo@sydney.edu.au \
    /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).