[Ocfs2-users] OCFS2 has a likely memory leak. Bug 864
John Lange
john.lange at open-it.ca
Tue Mar 27 17:13:48 PDT 2007
For those interested in this issue I have just uploaded 3 files to the
bug tracker including a pretty (ugly) graph...
http://oss.oracle.com/bugzilla/show_bug.cgi?id=864
John
On Tue, 2007-03-27 at 14:19 -0700, Alexei_Roudnev wrote:
> I can't follow the test guideline 1:1, because I run out of disk space in a
> very short time.
>
> I run delete with a big intervals (system created 3,000 directories ==
> 300,000 files, then deleted half of them, then sleep and repeat), and run
> test from 2 hosts, so it created much more heavy load onto the system:
> - some directories had simultaneous access (broker must work and control
> access)
> - files are not only created but deleted (one more operation),
> - I removed extra pauses.
>
> It shows that system have an object leak in the kernel, allocating about 512
> bytes per one new file (and never releasing them),
> so running it with 600,000 files eats about 300 MB of system memory (for
> internal buffers). It was another problem, well known as it was saying here,
> and I can't see +/- 56 bytes/file memory leak on base of this. There was not
> any memory leaks in user's space.
>
> On the other hand, it was not visible by vmstat at all, only by slabtop .
>
> Recommendation is the same after all (I did it already) - OCFSv2 can be used
> with light file load - use cases when # of file operations,
> such as create, remove, truncate etc is not high (but # of reads can be any,
> just as # of files in the file system). Not a surprise at all. I use OCFSv2
> for shared application directory (configs, binaries, logs) and cleaned it
> for use for the backups or even archive logs (@ Oracle) but not for the
> customer's data (and here we see, that my forecast was correct).
>
>
>
>
> ----- Original Message -----
> From: "John Lange" <john.lange at open-it.ca>
> To: "Alexei_Roudnev" <Alexei_Roudnev at exigengroup.com>
> Cc: "Sunil Mushran" <Sunil.Mushran at oracle.com>; "ocfs2-users"
> <ocfs2-users at oss.oracle.com>
> Sent: Tuesday, March 27, 2007 1:32 PM
> Subject: Re: [Ocfs2-users] OCFS2 has a likely memory leak. Bug 864
>
>
> > Just to be clear though, you need to follow the test outlined. Do _not_
> > delete the files.
> >
> > You must create them and flush the caches and then examine the free
> > memory. Graph it over a significant amount of time and then see if its a
> > downward trend.
> >
> > If you can, do a comparison to an ext3 partition as well.
> >
> > If this list supported attachments I would show you the two graphs, in
> > one, the free memory slopes downward (ocfs2), in the other free memory
> > is completely level.
> >
> > John
> >
> > On Tue, 2007-03-27 at 13:21 -0700, Alexei_Roudnev wrote:
> > > Run for 1 hour (even more), created 600,000 files (and removed then),
> from 2
> > > hosts.
> > >
> > > No memory leak problem, but # of slab-512 (not 256) growth - 77,000
> used,
> > > 600,000 objects active in slab-32 and slab-512.
> > >
> > > So there is object leak in the OCFSv2 / SLES9 Sp3, less aggressive than
> > > described one. Anyway, creating 100,000,000 files (and deleting them)
> will
> > > kill the system for sure (as I predicted before - OCFSv2 can be used, if
> you
> > > bhhave not intensive file creation or modification).
> > >
> > >
> > > Active / Total Objects (% used) : 1586075 / 1736513 (91.3%)
> > > Active / Total Slabs (% used) : 108815 / 108842 (100.0%)
> > > Active / Total Caches (% used) : 96 / 133 (72.2%)
> > > Active / Total Size (% used) : 398467.35K / 428911.02K (92.9%)
> > > Minimum / Average / Maximum Object : 0.02K / 0.25K / 128.00K
> > >
> > > OBJS ACTIVE USE OBJ SIZE SLABS OBJ/SLAB CACHE SIZE NAME
> > > 628096 628044 99% 0.03K 5608 112 22432K size-32
> > > 627352 627352 100% 0.50K 78419 8 313676K size-512
> > > 207600 151528 72% 0.09K 5190 40 20760K buffer_head
> > > 97320 83204 85% 0.12K 3244 30 12976K size-128
> > > 63450 14540 22% 0.25K 4230 15 16920K dentry_cache
> > > 31584 16754 53% 0.52K 4512 7 18048K radix_tree_node
> > > 19228 18049 93% 0.17K 874 22 3496K vm_area_struct
> > > 12384 9922 80% 0.02K 86 144 344K anon_vma
> > > 6210 5979 96% 0.25K 414 15 1656K filp
> > > 5730 2669 46% 0.25K 382 15 1528K size-256
> > > 3744 2782 74% 0.88K 936 4 3744K ext3_inode_cache
> > > 3390 3346 98% 0.62K 565 6 2260K inode_cache
> > > 3132 1855 59% 0.06K 54 58 216K size-64
> > > 2800 798 28% 0.02K 14 200 56K biovec-1
> > > 2605 2438 93% 0.75K 521 5 2084K proc_inode_cache
> > > 2378 1794 75% 0.06K 41 58 164K ocfs2_em_ent
> > > 1590 866 54% 0.12K 53 30 212K bio
> > >
> > >
> > >
> > >
> > > ----- Original Message -----
> > > From: "Sunil Mushran" <Sunil.Mushran at oracle.com>
> > > To: "Alexei_Roudnev" <Alexei_Roudnev at exigengroup.com>
> > > Cc: "John Lange" <john.lange at open-it.ca>; "ocfs2-users"
> > > <ocfs2-users at oss.oracle.com>
> > > Sent: Tuesday, March 27, 2007 12:36 PM
> > > Subject: Re: [Ocfs2-users] OCFS2 has a likely memory leak. Bug 864
> > >
> > >
> > > > You'll run into the size-256 slab explosion on sles9 sp3.
> > > > That issue was addressed in 1.2.4. sp3 ships 1.2.3.
> > > >
> > > > Alexei_Roudnev wrote:
> > > > > OCFSv2 @ SLES9 Sp3 build 283 is relatively stable. I am running your
> > > test on
> > > > > 2 hosts now (create files from 2 hosts, and delete them with some
> delay
> > > from
> > > > > host1 by rm -rf; without any sleep's; let's see how it works).
> > > > >
> > > > > I'll post results here.
> > > > >
> > > > > (I have impression, that SLES10 OCFSv2 is not stable at all - many
> > > numerous
> > > > > complains let me think, that it is not tested well, when
> > > > > they integrated OCFS into SLES10).
> > > > >
> > > >
> > >
> >
> >
>
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