Re: Bisected GFP in bfq_bfqq_expire on v5.1-rc1

From: Paolo Valente
Date: Mon Apr 01 2019 - 06:35:18 EST




> Il giorno 1 apr 2019, alle ore 11:22, Dmitrii Tcvetkov <demfloro@xxxxxxxxxxx> ha scritto:
>
> On Mon, 1 Apr 2019 11:01:27 +0200
> Paolo Valente <paolo.valente@xxxxxxxxxx> wrote:
>> Ok, thank you. Could you please do a
>>
>> list *(bfq_bfqq_expire+0x1f3)
>>
>> for me?
>>
>> Thanks,
>> Paolo
>>
>>>
>>> <gpf.txt><gpf-w-bfq-group-iosched.txt><config.txt>
>
> Reading symbols from vmlinux...done.
> (gdb) list *(bfq_bfqq_expire+0x1f3)
> 0xffffffff813d02c3 is in bfq_bfqq_expire (block/bfq-iosched.c:3390).
> 3385 * even in case bfqq and thus parent entities go on receiving
> 3386 * service with the same budget.
> 3387 */
> 3388 entity = entity->parent;
> 3389 for_each_entity(entity)
> 3390 entity->service = 0;
> 3391 }
> 3392
> 3393 /*
> 3394 * Budget timeout is not implemented through a dedicated timer, but

Thank you very much. Unfortunately this doesn't ring any bell. I'm
trying to reproduce the failure. It will probably take a little
time. If I don't make it, I'll ask you to kindly retry after applying
some instrumentation patch.

Thanks,
Paolo