* Mike Anderson <andmike@xxxxxxxxxxxxxxxxxx> wrote: > Ingo Molnar <mingo@xxxxxxx> wrote: > > > > * Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote: > > > > > I have no idea if this will make any difference for the > > > problem you're seeing, but it has been submitted and it's > > > worth trying out. If the problem still occurs, I'll write a > > > diagnostic patch to add log messages giving the destiny of > > > each request in scsi_io_completion(). > > > > OK, i've undone the reverts and have applied your fix - it will > > take a few hours to see whether the hang still occurs. > > I know already started your testing, but.. and that particular box already survived 20 test iterations in the past few hours - while it would hang after 5-10 iterations before. So i think Alan's fix is making a difference. I'll be able to tell for sure tomorrow morning. > I find it informative to set my scsi logging to the value > below to display non-zero IO status on commands. The overhead > impact is low for good completions. > > sysctl -w dev.scsi.logging_level=4100 > > Note: This does not provide the exact policy that > scsi_io_completion will take on the IO, but it provides the > input to scsi_io_completion which should help. will do that next time around i have a bug like this. (or if this bug triggers again) OTOH, the hang took quite a bit of IO to occur. Sometimes the box would be able to build a new kernel and reboot into it, without the hang. Ingo -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
