Red Hat Bugzilla – Bug 442316
kswap use total amount of CPU, system turns slow
Last modified: 2012-06-20 12:05:20 EDT
Description of problem:
kswap process hungs. Kswap process use total amount CPU. System become
unstable, apps hungs.
Version-Release number of selected component (if applicable):
2.4.9-e.35custom #3 SMP Thu Sep 2 11:51:12 CEST 2004 i686
Doing a backup, processing parallel tar.
Steps to Reproduce:
- Start a full backup.
- run multiple tar of lots of files.
No idle CPU available. Server turns very slow.
1:37pm up 78 days, 20:42, 2 users, load average: 5.03, 3.81, 3.92
702 processes: 698 sleeping, 4 running, 0 zombie, 0 stopped
CPU0 states: 4.3% user, 95.0% system, 0.0% nice, 0.0% idle
CPU1 states: 3.1% user, 96.2% system, 0.0% nice, 0.0% idle
Mem: 3863264K av, 3847672K used, 15592K free, 2172K shrd, 309080K buff
Swap: 2040244K av, 1436248K used, 603996K free 1912112K cached
PID USER PRI NI SIZE RSS SHARE STAT %CPU %MEM TIME COMMAND
6 root 25 0 0 0 0 RW 75.5 0.0 526:15 kswapd
3843 oracle 39 0 1904 1904 848 R 25.1 0.0 0:13 top
3981 oracle 39 0 5548 4404 3804 R 23.1 0.1 0:03 opmn
3987 oracle 39 0 1188 1184 552 R 20.8 0.0 0:00 ps
9509 root 30 0 2356 1916 1520 S 10.7 0.0 3:06 vbda
2842 root 0 -20 4612 4608 1960 S < 4.1 0.1 29:01 scopeux
31048 oracle 25 0 45280 38M 21724 S 2.2 1.0 20:58 emagent
9473 root 16 0 2348 1920 1740 D 1.6 0.0 5:15 vbda
20197 oracle 18 0 169M 74M 76008 S 0.9 1.9 0:01 java
Anybody know how to Fix it? I have readed about it in
https://bugzilla.redhat.com/show_bug.cgi?id=132639, but is a too old reference.
Thanks in advance.
The current AS2.1 supported kernel is 2.4.9-e.72. A number of vm-related bugs
have been fixed since -e.35. Is this problem present in 2.4.9-e.72?
Hi Daniel -
I don't have enough info to go on and have not heard back from you.
I'm going to close this bug. If you'd like to persue this further, please
re-open this bug, and open a case with redhat support at enterprise.redhat.com.
What kind of info do you want to know?
When I begin a backup, machine turns very slow, and making a top, CPU usage is
100%. Sometimes services, applications or all machine hungs.
Thanks in advance.
I have two identical machines, and both have same problem.
Can you reproduce this problem on 2.4.9-e.72? If so, can you provide sysrq-m
and sysrq-t output?
Then, Is the problem fixed in 2.4.9-e.72?
Or is this a test?
Hi Daniel -
e.35custom is a _very_ old kernel, and not one that we can support at this point. As I said in comment 1, there have been a number of vm patches, several specifically for kswapd since e.35. Please give e.72 a try. If the problem occurs there, please collect the sysrq info and post it here.
Thank you for submitting this issue for consideration in Red Hat Enterprise Linux. The release for which you requested us to review is now End of Life.
Please See https://access.redhat.com/support/policy/updates/errata/
If you would like Red Hat to re-consider your feature request for an active release, please re-open the request via appropriate support channels and provide additional supporting details about the importance of this issue.