Re: [PATCH v3] fs: record task name which froze superblock

[Alexey Dobriyan]

On Mon, Mar 2, 2015 at 7:38 AM, Mateusz Guzik <mguzik@xxxxxxxxxx> wrote:

> As explained below, this one task name is already very useful and likely
> covers majority of real life use cases.
>
> While working in support we were getting a lot of vmcores where hung task
> detector panicked the kernel because a lot of tasks were blocked
> in UN state trying to write to frozen filesystems. I presume OP has
> similar story.

Yes, the intended "use" case is 1 freezer which hopefully covers
majority of bug reports.

> Some back on forth commuication almost always revealed one process e.g.
> freezing stuff and then blocking itself trying to access it. While we
> could see it blocked, we had no presumptive evidence to pin freezing on
> it. A matching name, while still not 100% conclusive, would be ok enough
> to push the case forward and avoid a rountrip of systemap scripts
> showing freezer process tree.
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