On Wed, 21 Jun 2023 11:03:48 -0400 Luben Tuikov <luben.tuikov@xxxxxxx> wrote: > On 2023-06-21 10:53, Boris Brezillon wrote: > > On Wed, 21 Jun 2023 10:41:22 -0400 > > Luben Tuikov <luben.tuikov@xxxxxxx> wrote: > > > >> On 2023-06-21 10:18, Boris Brezillon wrote: > >>> Hello Luben, > >>> > >>> On Wed, 21 Jun 2023 09:56:40 -0400 > >>> Luben Tuikov <luben.tuikov@xxxxxxx> wrote: > >>> > >>>> On 2023-06-19 03:19, Boris Brezillon wrote: > >>>>> drm_sched_entity_kill_jobs_cb() logic is omitting the last fence popped > >>>>> from the dependency array that was waited upon before > >>>>> drm_sched_entity_kill() was called (drm_sched_entity::dependency field), > >>>>> so we're basically waiting for all dependencies except one. > >>>>> > >>>>> In theory, this wait shouldn't be needed because resources should have > >>>>> their users registered to the dma_resv object, thus guaranteeing that > >>>>> future jobs wanting to access these resources wait on all the previous > >>>>> users (depending on the access type, of course). But we want to keep > >>>>> these explicit waits in the kill entity path just in case. > >>>>> > >>>>> Let's make sure we keep all dependencies in the array in > >>>>> drm_sched_job_dependency(), so we can iterate over the array and wait > >>>>> in drm_sched_entity_kill_jobs_cb(). > >>>>> > >>>>> We also make sure we wait on drm_sched_fence::finished if we were > >>>>> originally asked to wait on drm_sched_fence::scheduled. In that case, > >>>>> we assume the intent was to delegate the wait to the firmware/GPU or > >>>>> rely on the pipelining done at the entity/scheduler level, but when > >>>>> killing jobs, we really want to wait for completion not just scheduling. > >>>>> > >>>>> v6: > >>>>> - Back to v4 implementation > >>>>> - Add Christian's R-b > >>>>> > >>>>> v5: > >>>>> - Flag deps on which we should only wait for the scheduled event > >>>>> at insertion time > >>>>> > >>>>> v4: > >>>>> - Fix commit message > >>>>> - Fix a use-after-free bug > >>>>> > >>>>> v3: > >>>>> - Always wait for drm_sched_fence::finished fences in > >>>>> drm_sched_entity_kill_jobs_cb() when we see a sched_fence > >>>>> > >>>>> v2: > >>>>> - Don't evict deps in drm_sched_job_dependency() > >>>> > >>>> Hmm, why is this in reverse chronological order? > >>>> It's very confusing. > >>> > >>> Dunno, that's how I've always ordered things, and quick look at some > >>> dri-devel patches [1][2] makes me think I'm not the only one to start > >>> from the latest submission. > >>> > >>> [1]https://lkml.org/lkml/2023/6/19/941 > >>> [2]https://lore.kernel.org/dri-devel/cover.1686729444.git.Sandor.yu@xxxxxxx/T/#t > >>> > >>>> > >>>>> > >>>>> Signed-off-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxx> > >>>>> Suggested-by: "Christian König" <christian.koenig@xxxxxxx> > >>>>> Reviewed-by: "Christian König" <christian.koenig@xxxxxxx> > >>>> > >>>> These three lines would usually come after the CCs. > >>> > >>> Again, I think I've always inserted those tags before the Cc, but I can > >>> re-order things if you prefer. Let me know if you want me to send a v7 > >>> addressing the Cc+changelog ordering. > >> > >> No, it's not necessary for this patch, but in the future I'd rather follow > >> chronological ordering for the versions, and in the Cc list. It's similar > >> to how the patch description follows (narrative text) and to how we reply > >> back to emails, and prevalently in the kernel log in drm ("git log" should > >> suffice). > >> > >> Reading in chronological progression builds a narrative, a picture, in one's > >> mind and makes it easy to see justifications for said narrative, or see reasons > >> to change the narrative. > >> > >> That is, one can make a better decision knowing the full history, rather than > >> only the latest change. > >> > >> (And in fact when I read the version revision list, my eyes skip over v[X] > >> and just read down, so I was wondering why and how Christian R-B the patch > >> in v2, and it wasn't until I actually saw that they were ordered in reverse > >> chronological order, which was in fact v6--listed first, which I'd assumed > >> was listed last.) > >> > >> Do you have access or do you know who is pushing this patch to drm-misc-fixes? > > > > I can push it. > > > > Acked-by: Luben Tuikov <luben.tuikov@xxxxxxx> Queued to drm-misc-fixes after re-ordering things in the commit message as you suggested. Regards, Boris
