On Thu, Mar 10, 2022 at 9:19 AM Sharma, Shashank <shashank.sharma@xxxxxxx> wrote: > > > > On 3/10/2022 6:10 PM, Rob Clark wrote: > > On Thu, Mar 10, 2022 at 8:21 AM Sharma, Shashank > > <shashank.sharma@xxxxxxx> wrote: > >> > >> > >> > >> On 3/10/2022 4:24 PM, Rob Clark wrote: > >>> On Thu, Mar 10, 2022 at 1:55 AM Christian König > >>> <ckoenig.leichtzumerken@xxxxxxxxx> wrote: > >>>> > >>>> > >>>> > >>>> Am 09.03.22 um 19:12 schrieb Rob Clark: > >>>>> On Tue, Mar 8, 2022 at 11:40 PM Shashank Sharma > >>>>> <contactshashanksharma@xxxxxxxxx> wrote: > >>>>>> From: Shashank Sharma <shashank.sharma@xxxxxxx> > >>>>>> > >>>>>> 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. > >> > >> I had a quick look at the devcoredump code, and it doesn't look like > >> that is sending an event to the user, so we still need an event to > >> indicate a GPU reset. > > > > There definitely is an event to userspace, I suspect somewhere down > > the device_add() path? > > > > Let me check that out as well, hope that is not due to a driver-private > event for GPU reset, coz I think I have seen some of those in a few DRM > drivers. > Definitely no driver private event for drm/msm .. I haven't dug through it all but this is the collector for devcoredump, triggered somehow via udev. Most likely from event triggered by device_add() https://chromium.googlesource.com/chromiumos/platform2/+/HEAD/crash-reporter/udev_collector.cc BR, -R
