Re: [Ext2-devel] Re: OOM problems on 2.6.12-rc1 with many fsx tests

Mingming Cao
2005-04-05T17:26:50Z

On Mon, 2005-04-04 at 13:04 -0700, Andrew Morton wrote:
> Mingming Cao <cmm@us.ibm.com> wrote:
> >
> > On Sun, 2005-04-03 at 18:35 -0700, Andrew Morton wrote:
> > > Mingming Cao <cmm@us.ibm.com> wrote:
> > > >
> > > > I run into OOM problem again on 2.6.12-rc1. I run some(20) fsx tests on
> > > > 2.6.12-rc1 kernel(and 2.6.11-mm4) on ext3 filesystem, after about 10
> > > > hours the system hit OOM, and OOM keep killing processes one by one. I
> > > > could reproduce this problem very constantly on a 2 way PIII 700MHZ with
> > > > 512MB RAM. Also the problem could be reproduced on running the same test
> > > > on reiser fs.
> > > >
> > > > The fsx command is:
> > > >
> > > > ./fsx -c 10 -n -r 4096 -w 4096 /mnt/test/foo1 &
> > >
> > >
> > > This ext3 bug goes all the way back to 2.6.6.
> >
> > > I don't know yet why you saw problems with reiser3 and I'm pretty sure I
> > > saw problems with ext2. More testing is needed there.
> > >
> >
> > We (Janet and I) are chasing this bug as well. Janet is able to
> > reproduce this bug on 2.6.9 but I can't. Glad to know you have nail down
> > this issue on ext3. I am pretty sure I saw this on Reiser3 once, I will
> > double check it. Will try your patch today.
>
> There's a second leak, with similar-looking symptoms. At ~50
> commits/second it has leaked ~10MB in 24 hours, so it's very slow - less
> than a hundredth the rate of the first one.
>

I run the test(20 instances of fsx) with your patch on 2.6.12-rc1 with
512MB RAM (where I were able to constantly re-create the mem leak and
lead to OOM before). The result is the kernel did not get into OOM after
about 19 hours(before it took about 9 hours or so), system is still
responsive. However I did notice about ~60MB delta between Active
+Inactive and Buffers+cached+Swapcached+Mapped+Slab

Here is the current /proc/meminfo

elm3b92:~ # cat /proc/meminfo
MemTotal: 510400 kB
MemFree: 97004 kB
Buffers: 196772 kB
Cached: 77608 kB
SwapCached: 0 kB
Active: 299064 kB
Inactive: 83140 kB
HighTotal: 0 kB
HighFree: 0 kB
LowTotal: 510400 kB
LowFree: 97004 kB
SwapTotal: 1052216 kB
SwapFree: 1052216 kB
Dirty: 1600 kB
Writeback: 0 kB
Mapped: 23256 kB
Slab: 24548 kB
CommitLimit: 1307416 kB
Committed_AS: 73560 kB
PageTables: 532 kB
VmallocTotal: 516024 kB
VmallocUsed: 3700 kB
VmallocChunk: 512320 kB