Re: 3.17-rc6: bcache_gc: BUG: soft lockup - CPU#2 stuck for 23s!

Stefan Seyfried
2014-11-22T12:46:08Z

Hi Eric,

Am 22.11.2014 um 01:22 schrieb Eric Wheeler:
>> Before the patch goes upstream I need it tested so I know if it fixes
>> the actual issue or not.
>
> We have been using the rcu_sched patch and the cond_resched patch together
> (both attached) since November 3rd on 3.17.2 without any bcache
> backtraces. bcache is running in writeback mode. The server is
> predominantly write-only with relatively few reads.

Is the rcu_sched patch supposed to help the same or a totally different
problem? Means: should I also apply it, rebuild the module and reboot
(resetting the test time to zero :-)

I had the "deadly" soft lockup once per week since updating to
3.16/3.17, so I can only tell if it might help in two weeks earliest.

> To sum up, the attached two patches (plus the for-jens pull) have fixed all
> of our bcache problems since 3.14.y. These patches on 3.17.2 seem quite stable.

That's good to hear :-)

Best regards,

Stefan
--
Stefan Seyfried
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