Re: [PATCH BUGFIX] block, bfq: access and cache blkg data only when safe

From: Paolo Valente
Date: Mon May 22 2017 - 16:20:14 EST



> Il giorno 19 mag 2017, alle ore 16:37, Jens Axboe <axboe@xxxxxxxxx> ha scritto:
>
> On 05/19/2017 02:39 AM, Paolo Valente wrote:
>> @@ -692,8 +725,7 @@ void bfq_pd_offline(struct blkg_policy_data *pd)
>> /*
>> * The idle tree may still contain bfq_queues belonging
>> * to exited task because they never migrated to a different
>> - * cgroup from the one being destroyed now. No one else
>> - * can access them so it's safe to act without any lock.
>> ++ * cgroup from the one being destroyed now.
>> */
>> bfq_flush_idle_tree(st);
>>
>
> Looks like an extra '+' snuck into that hunk.
>

Yes, sorry. Before possibly submitting a fixed version, I'll wait for
a reply on my previous email in this thread, as the issue now seems
more serious to me, and affecting CFQ too.

Thanks,
Paolo

> --
> Jens Axboe
>