Messages in this thread |  | | From | "Rechenberg, Andrew" <> | Subject | RE: kupdated high load with heavy disk I/O | Date | Tue, 20 Nov 2001 17:58:44 -0500 |
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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/ >
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