Re: [Bug 9182] Critical memory leak (dirty pages)

[Krzysztof Oledzki]

On Thu, 13 Dec 2007, Krzysztof Oledzki wrote:

> On Thu, 13 Dec 2007, Peter Zijlstra wrote:
>
> > On Thu, 2007-12-13 at 16:17 +0100, Krzysztof Oledzki wrote:
> > >
> >
> > > BTW: Could someone please look at this problem? I feel little ignored and
> > > in my situation this is a critical regression.
> >
> > I was hoping to get around to it today, but I guess tomorrow will have
> > to do :-/
>
> Thanks.
>
> > So, its ext3, dirty some pages, sync, and dirty doesn't fall to 0,
> > right?
>
> Not only doesn't fall but continuously grows.
>
> > Does it happen with other filesystems as well?
>
> Don't know. I generally only use ext3 and I'm afraid I'm not able to switch 
> this system to other filesystem.
>
> > What are you ext3 mount options?
> /dev/root / ext3 rw,data=journal 0 0
> /dev/VolGrp0/usr /usr ext3 rw,nodev,data=journal 0 0
> /dev/VolGrp0/var /var ext3 rw,nodev,data=journal 0 0
> /dev/VolGrp0/squid_spool /var/cache/squid/cd0 ext3 
> rw,nosuid,nodev,noatime,data=writeback 0 0
> /dev/VolGrp0/squid_spool2 /var/cache/squid/cd1 ext3 
> rw,nosuid,nodev,noatime,data=writeback 0 0
> /dev/VolGrp0/news_spool /var/spool/news ext3 
> rw,nosuid,nodev,noatime,data=ordered 0 0

BTW: this regression also exists in 2.6.24-rc5. I'll try to find when it 
was introduced but it is hard to do it on a highly critical production 
system, especially since it takes ~2h after a reboot, to be sure.

However, 2h is quite good time, on other systems I have to wait ~2 months 
to get 20MB of leaked memory:

# uptime
 13:29:34 up 58 days, 13:04,  9 users,  load average: 0.38, 0.27, 0.31

# sync;sync;sleep 1;sync;grep Dirt /proc/meminfo
Dirty:           23820 kB

Best regards,

				Krzysztof Olędzki