lkml.org 
[lkml]   [2001]   [Nov]   [20]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRE: kupdated high load with heavy disk I/O
Date
I have to find time to down the box because it's production, but as soon as
I do I'll post the numbers here.

Thanks for your help.

Regards,
Andy.


> Could you please guys try to reproduce the problem with kernel profiling
> turned on and send us the output of readprofile?

> This way we can know which function is using more CPU time, thus we can
> identify the problem.


On Wed, 14 Nov 2001, John McCutchan wrote:

> Hi,
>
> I also have the exact same behaviour when running mkisofs. During the
> creation of the ISO the interactive feel is sluggish and after mkisofs
> is complete the box is sluggish and appears to lock up. During
> this sluggish period there is alot of disk activity. This is under
> 2.4.14
>
> John
> On Wed, Nov 14, 2001 at 06:01:23PM -0500, Rechenberg, Andrew wrote:
> > Hello,
> >
> > I have read some previous threads about kupdated consuming 99% of CPU
under
> > intense disk I/O in kernel 2.4.x on the archives of linux-kernel (April
> > 2001), and some issues about I/O problems on linux-mm, but have yet to
find
> > any suggestions or fixes. I am currently experiencing the same issue
and
> > was wondering if anyone has any thoughts or suggestions on the issue. I
am
> > not subscribed to the list so would you please CC: me directly on any
> > responses? I can also check out the archives at theaimsgroup.com if a
CC:
> > would not be appropriate. Thank you.
> >
> > The issue that I am having is that when there is a heavy amount a disk
I/O,
> > the box becomes slightly unresponsive and kupdated is using 99.9% in
'top.'
> > Sometimes the box appears to totally lock up. If one waits several
seconds
> > to a couple of minutes the system appears to 'unlock' and runs
sluggishly
> > for a while. This cycle will repeat itself until the I/O subsides. The
> > memory usage goes up to the full capacity of the box and then about 10MB
of
> > swap is used while this problem is occurring. Memory and swap does not
get
> > relinquished afer the incident.
> >
> > The issue appears in kernel 2.4.14 compiled directly from source from
> > kernel.org with no patches. These problems manifest themselves with
only
> > one user doing heavy disk I/O. The normal user load on the box can run
> > between 350-450 users so this behavior would be unacceptable because the
> > application that is being run is interactive. With 450 users, and the
same
> > process running on a 2.2.20 kernel the performance of the box is great,
with
> > only a very slightly noticeable slow down.
> >
> > I am running the Informix database UniVerse version 9.6.2.4 on a 4
processor
> > 700MHz Xeon Dell PowerEdge 6400. The disk subsystem is controlled by a
PERC
> > 2/DC RAID card with 128MB on-board cache (megaraid driver compiled
directly
> > in to the kernel). Data array is on 5 36GB 10K Ultra160 disks in a
RAID5
> > configuration. The box has 4GB RAM, but is only using 2GB due to the
move
> > back to the 2.2 kernel. The only kernel paramters that have been
modified
> > are in /proc/sys/kernel/sem. All filesystems are ext2.
> >
> > If you need any more detailed info, please let me know. Any help on
this
> > problem would be immensely appreciated. Thank you in advance.
> >
> > Regards,
> > Andrew Rechenberg
> > Network Team, Sherman Financial Group
> > arechenberg@shermanfinancialgroup.com
> >
> > --
> > 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/
> >
> --
> 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/
>

--
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/
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 13:13    [W:0.043 / U:0.548 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site