This is really strange. Day before, I updated the machine here (x86_64) and all went normal. I rebooted, and everything came back just as I expected. Next morning, I noticed one of my jobs during the night had finished, but finished late by about 8 or 9 minutes. I really didn't think much of it, but after looking at jobs running today, I'm seeing the same thing. Processes that used to take 3.75 hours to complete are now taking 4 hours. ( I have cron jobs that were running to process the data after the main run, and they busted) Nothing has changed in the way the model runs, and there have been no changes to input data or any other parameter that would cause a longer runtime. So, the question is, did something change in the kernel that would make the machine run slower? I do have threading turned on in the bios, and all 4 cpu's are shown via dmesg. In fact, I looked at the dmesg output after a reboot and due to another message about losing clock tics, I just checked that I had not encountered the same. Short of rebooting back into the previous kernel, is there any way to tell if something is slowing the box down? -- Sam W.Drinkard -- sam at wa4phy.net WEB http://wa4phy.net Augusta Area Mesonet cell 706.825.8513 Home 706.868.7253 MAIL 4438 Branchwood Drive, Martinez Georgia, 30907-1304
On Thu, 2006-06-01 at 15:54 -0400, Sam Drinkard wrote:> This is really strange. Day before, I updated the machine here (x86_64) > and all went normal. I rebooted, and everything came back just as I > expected. Next morning, I noticed one of my jobs during the night had > finished, but finished late by about 8 or 9 minutes. I really didn't > think much of it, but after looking at jobs running today, I'm seeing > the same thing. Processes that used to take 3.75 hours to complete are > now taking 4 hours. ( I have cron jobs that were running to process the > data after the main run, and they busted) Nothing has changed in the > way the model runs, and there have been no changes to input data or any > other parameter that would cause a longer runtime. So, the question is, > did something change in the kernel that would make the machine run > slower? I do have threading turned on in the bios, and all 4 cpu's are > shown via dmesg. In fact, I looked at the dmesg output after a reboot > and due to another message about losing clock tics, I just checked that > I had not encountered the same. Short of rebooting back into the > previous kernel, is there any way to tell if something is slowing the > box down? >There is an issue with VM configuration that might cause swapping and that COULD slow the machine down. However ... since it was an "Important kernel securtity update" ... I would at least read this before booting into the old kernel: https://rhn.redhat.com/errata/RHSA-2006-0493.html Here is details concerning the VM issue: https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=188141 I reality that bug started last kernel ... but I have noticed more on this one. -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 189 bytes Desc: This is a digitally signed message part URL: <http://lists.centos.org/pipermail/centos/attachments/20060601/d33223fc/attachment-0003.sig>
Johnny,
After reading about the VM issue, I concur. The previous kernel did
exhibit the behavior noted in the URL you sent. Looking right now, I
see a considerable difference in use / swap. The software running on
the machine generally uses anwhere from 1.2 > 1.4Gb of memory, and I had
noticed swap would, over time, increase, while there was still *some*
memory available, but it never would use totally all of it. The
application running right now is a little different from the one that
runs late-night and after 16z, so I'll take a peek at it either tonight
if I'm up or in the a.m. after the thing starts. I'll also note swap
and its size as time progresses to see if it increases as before with
free mem.
Thanks for the info.
--
Sam W.Drinkard -- sam at wa4phy.net
WEB http://wa4phy.net
Augusta Area Mesonet
cell 706.825.8513 Home 706.868.7253
MAIL 4438 Branchwood Drive,
Martinez Georgia, 30907-1304