Re: dcache leak in 2.6.16-git8 II

[Andrew Morton <akpm@osdl.org>]

Andi Kleen <ak@suse.de> wrote:
>
> On Tuesday 28 March 2006 05:00, Andrew Morton wrote:
> > Andi Kleen <ak@suse.de> wrote:
> > >
> > > On Monday 27 March 2006 13:48, Bharata B Rao wrote:
> > > > On Mon, Mar 27, 2006 at 07:50:20AM +0200, Andi Kleen wrote:
> > > > > 
> > > > > A 2GB x86-64 desktop system here is currently swapping itself to death after
> > > > > a few days uptime.
> > > > > 
> > > > > Some investigation shows this:
> > > > > 
> > > > > inode_cache         1287   1337    568    7    1 : tunables   54   27    8 : slabdata    191    191      0
> > > > > dentry_cache      1867436 1867643    208   19    1 : tunables  120   60    8 : slabdata  98297  98297      0
> > > > > 
> > > > 
> > > > Would it be possible to try out this experimental patch which
> > > > gets some stats from the dentry cache ?
> > > 
> > > It should be trivial to reproduce by other people. Biggest workload
> > > is kernel compiles and quilt.
> > > 
> > > After a few hours with -git12 it's already at
> > > 
> > > dentry_cache      947013 952014    208   19    1 : tunables  120   60    8 : slabdata  50100  50106    480
> > > 
> > > and starting to go into swap.
> > > 
> > > I can't imagine I'm the only one seeing this?
> > > 
> > > I have a few x86-64 patches applied too, but they don't change anything
> > > in this area.
> > 
> > I don't think I can reproduce this on x86 uniproc.  (avtab_node_cache
> > is a different story - maintainers separately pinged).
> 
> 
> I got another OOM from this with -git13. Unfortunately it seems to take a few days at least
> to trigger.
> 
> dentry_cache      999168 1024594    208   19    1 : tunables  120   60    8 : slabdata  53926  53926      0 : shrinker stat 18522624 8871000
> 
> Hrm interesting is this one:
> 
> sock_inode_cache  996784 996805    704    5    1 : tunables   54   27    8 : slabdata 199361 199361      0
> 
> Most of the leaked dentries seem to be sockets. I didn't notice this earlier.
> 
> This was with the debugging patches applied btw. 
> 
> So maybe we have a socket leak?

It looks that way.  Didn't someone else report a sock_inode_cache leak?

> I still got a copy of the /proc in case anybody wants more information.

We have this fancy new /proc/slab_allocators now, it might show something
interesting.  It needs CONFIG_DEBUG_SLAB_LEAK.