[AMD Official Use Only - AMD Internal Distribution Only] Hi Christian,
The real issue is a race condition during process exit after patch https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=1f02f2044bda1db1fd995bc35961ab075fa7b5a2. This patch changed amdgpu_vm_wait_idle to use drm_sched_entity_flush instead of dma_resv_wait_timeout. Here is what happens: do_exit | exit_files(tsk) ... amdgpu_flush ... amdgpu_vm_wait_idle ... drm_sched_entity_flush (kills entity) ... exit_task_work(tsk) ...amdgpu_gem_object_close ... amdgpu_vm_clear_freed (tries to submit to killed entity) The entity gets killed in amdgpu_vm_wait_idle(), but amdgpu_vm_clear_freed() called by exit_task_work() still tries to submit jobs. Kind regards, Esther -----Original Message----- From: Koenig, Christian <christian.koe...@amd.com> Sent: Monday, August 11, 2025 4:25 PM To: Liu01, Tong (Esther) <tong.li...@amd.com>; dri-devel@lists.freedesktop.org Cc: pha...@kernel.org; d...@kernel.org; matthew.br...@intel.com; Ba, Gang <gang...@amd.com>; matthew.schwa...@linux.dev; cao, lin <lin....@amd.com>; cao, lin <lin....@amd.com> Subject: Re: [PATCH] drm/amdgpu: fix task hang from failed job submission during process kill On 11.08.25 09:20, Liu01 Tong wrote: > During process kill, drm_sched_entity_flush() will kill the vm > entities. The following job submissions of this process will fail Well when the process is killed how can it still make job submissions? Regards, Christian. >, and > the resources of these jobs have not been released, nor have the >fences been signalled, causing tasks to hang. > > Fix by not doing job init when the entity is stopped. And when the job > is already submitted, free the job resource if the entity is stopped. > > Signed-off-by: Liu01 Tong <tong.li...@amd.com> > Signed-off-by: Lin.Cao <linca...@amd.com> > --- > drivers/gpu/drm/scheduler/sched_entity.c | 13 +++++++------ > drivers/gpu/drm/scheduler/sched_main.c | 5 +++++ > 2 files changed, 12 insertions(+), 6 deletions(-) > > diff --git a/drivers/gpu/drm/scheduler/sched_entity.c > b/drivers/gpu/drm/scheduler/sched_entity.c > index ac678de7fe5e..1e744b2eb2db 100644 > --- a/drivers/gpu/drm/scheduler/sched_entity.c > +++ b/drivers/gpu/drm/scheduler/sched_entity.c > @@ -570,6 +570,13 @@ void drm_sched_entity_push_job(struct drm_sched_job > *sched_job) > bool first; > ktime_t submit_ts; > > + if (entity->stopped) { > + DRM_ERROR("Trying to push job to a killed entity\n"); > + INIT_WORK(&sched_job->work, drm_sched_entity_kill_jobs_work); > + schedule_work(&sched_job->work); > + return; > + } > + > trace_drm_sched_job(sched_job, entity); > atomic_inc(entity->rq->sched->score); > WRITE_ONCE(entity->last_user, current->group_leader); @@ -589,12 > +596,6 @@ void drm_sched_entity_push_job(struct drm_sched_job > *sched_job) > > /* Add the entity to the run queue */ > spin_lock(&entity->lock); > - if (entity->stopped) { > - spin_unlock(&entity->lock); > - > - DRM_ERROR("Trying to push to a killed entity\n"); > - return; > - } > > rq = entity->rq; > sched = rq->sched; > diff --git a/drivers/gpu/drm/scheduler/sched_main.c > b/drivers/gpu/drm/scheduler/sched_main.c > index bfea608a7106..c15b17d9ffe3 100644 > --- a/drivers/gpu/drm/scheduler/sched_main.c > +++ b/drivers/gpu/drm/scheduler/sched_main.c > @@ -795,6 +795,11 @@ int drm_sched_job_init(struct drm_sched_job *job, > return -ENOENT; > } > > + if (unlikely(entity->stopped)) { > + pr_err("*ERROR* %s: entity is stopped!\n", __func__); > + return -EINVAL; > + } > + > if (unlikely(!credits)) { > pr_err("*ERROR* %s: credits cannot be 0!\n", __func__); > return -EINVAL;
