Red Hat Bugzilla – Bug 480165
RHEL 4.8 kernel rhts fs_mark test hangs
Last modified: 2012-06-07 10:42:15 EDT
Description of problem:
fs_mark test hangs on ppc64 machine and localwatchdog hits. Looks like fs_mark is waiting for some journal commit and kjournald is waiting for some some bio transfer to finish but that bio transfer never finishes. So it could be a device driver issue or something like that.
Interesting thing is that it happens most of the time on ibm-l4b-lp1.test.redhat.com machine.
There are more instances of failure. Not listing all of them.
Version-Release number of selected component (if applicable):
Saw it multitple time during various rhts runs.
Steps to Reproduce:
1. run fs_mark test on ibm-l4b-lp1.test.redhat.com
Noticed one more instance of the issue in 79.EL kernel.
how does one get access to this box? i have to get an objdump of jbd so i can map where we hung. It seems to me though that this is just jbd getting hung up because its waiting for IO to happen, so its a device driver problem. Once I can map where we're hung in do_get_write_access I can confirm thats the case, or not if its not.
This machine is in rhts. You can reserve the machine and use it.
OK finally figured out how to get what I needed. The hang is just us waiting on the buffer lock, so we're waiting for IO to complete. It looks to be a problem at a lower layer, I'm not sure who would be good to assign it to for that sort of thing.
Retesting /kernel/performance/fs_mark on ibm-l4b-lp1.test.redhat.com with kernel 2.6.9-90.EL:
Kernel 2.6.9-90.EL installed and /kernel/performance/fs_mark was run on
ibm-l4b-lp1.rhts.eng.rdu.redhat.com without issue 5x. The results look good.