Re: [PATCH v2 1/2] drm: Add GPU reset sysfs event

[Rob Clark <robdclark@gmail.com>]

On Thu, Mar 10, 2022 at 1:55 AM Christian König
<ckoenig.leichtzumerken@gmail.com> wrote:
>
>
>
> Am 09.03.22 um 19:12 schrieb Rob Clark:
> > On Tue, Mar 8, 2022 at 11:40 PM Shashank Sharma
> > <contactshashanksharma@gmail.com> wrote:
> >> From: Shashank Sharma <shashank.sharma@amd.com>
> >>
> >> This patch adds a new sysfs event, which will indicate
> >> the userland about a GPU reset, and can also provide
> >> some information like:
> >> - process ID of the process involved with the GPU reset
> >> - process name of the involved process
> >> - the GPU status info (using flags)
> >>
> >> This patch also introduces the first flag of the flags
> >> bitmap, which can be appended as and when required.
> > Why invent something new, rather than using the already existing devcoredump?
>
> Yeah, that's a really valid question.
>
> > I don't think we need (or should encourage/allow) something drm
> > specific when there is already an existing solution used by both drm
> > and non-drm drivers.  Userspace should not have to learn to support
> > yet another mechanism to do the same thing.
>
> Question is how is userspace notified about new available core dumps?

I haven't looked into it too closely, as the CrOS userspace
crash-reporter already had support for devcoredump, so it "just
worked" out of the box[1].  I believe a udev event is what triggers
the crash-reporter to go read the devcore dump out of sysfs.

BR,
-R

[1] One small change to allow-list the drm/msm devcore dumps was
needed after a privacy review/audit of what is contained in the GPU
devcored to ensure it does not contain any PII .. for CrOS on amd
devices I'd be happy to walk whoever deals with amd CrOS devices
through the process offline.

> Regards,
> Christian.
>
> >
> > BR,
> > -R
>