Re: [RFC] hung_task:add detecting task in D state milliseconds timeout

From: yang che
Date: Thu Jul 02 2020 - 23:18:48 EST


my understanding, KernelShark can't trigger panic, hung_task can
trigger. According to my use,
sometimes need to trigger panic to grab ramdump to analyze lock and
memory problems.
So I want to increase this millisecond support.


Matthew Wilcox <willy@xxxxxxxxxxxxx> ä2020å7æ3æåä äå1:43åéï
>
> On Thu, Jul 02, 2020 at 10:08:13PM +0800, yang che wrote:
> > current hung_task_check_interval_secs and hung_task_timeout_secs
> > only supports seconds.in some cases,the TASK_UNINTERRUPTIBLE state
> > takes less than 1 second.The task of the graphical interface,
> > the unterruptible state lasts for hundreds of milliseconds
> > will cause the interface to freeze
>
> The primary problem I see with this patch is that writing to the
> millisecond file silently overrides the setting in the seconds file.
> If you end up redoing this patch, there needs to be one variable which
> is scaled when reading/writing the seconds file.
>
> Taking a step back though, I think this is the wrong tool for the job.
> I'm pretty sure KernelShark will do what you want without any kernel
> modifications.
>