On 10/22/19 2:28 PM, Yang, Philip wrote: > If device reset/suspend/resume failed for some reason, dqm lock is > hold forever and this causes deadlock. Below is a kernel backtrace when > application open kfd after suspend/resume failed. > > Instead of holding dqm lock in pre_reset and releasing dqm lock in > post_reset, add dqm->device_stopped flag which is modified in > dqm->ops.start and dqm->ops.stop. The flag doesn't need lock protection > because write/read are all inside dqm lock. > > For HWS case, map_queues_cpsch and unmap_queues_cpsch checks > device_stopped flag before sending the updated runlist. Is there a chance of race condition here where dqm->device_stopped returns true for some operation (e.g.map_queues_cpsch) but just as it proceeds GPU reset starts ? Andrey > > v2: For no-HWS case, when device is stopped, don't call > load/destroy_mqd for eviction, restore and create queue, and avoid > debugfs dump hdqs. > > Backtrace of dqm lock deadlock: > > [Thu Oct 17 16:43:37 2019] INFO: task rocminfo:3024 blocked for more > than 120 seconds. > [Thu Oct 17 16:43:37 2019] Not tainted > 5.0.0-rc1-kfd-compute-rocm-dkms-no-npi-1131 #1 > [Thu Oct 17 16:43:37 2019] "echo 0 > > /proc/sys/kernel/hung_task_timeout_secs" disables this message. > [Thu Oct 17 16:43:37 2019] rocminfo D 0 3024 2947 > 0x80000000 > [Thu Oct 17 16:43:37 2019] Call Trace: > [Thu Oct 17 16:43:37 2019] ? __schedule+0x3d9/0x8a0 > [Thu Oct 17 16:43:37 2019] schedule+0x32/0x70 > [Thu Oct 17 16:43:37 2019] schedule_preempt_disabled+0xa/0x10 > [Thu Oct 17 16:43:37 2019] __mutex_lock.isra.9+0x1e3/0x4e0 > [Thu Oct 17 16:43:37 2019] ? __call_srcu+0x264/0x3b0 > [Thu Oct 17 16:43:37 2019] ? process_termination_cpsch+0x24/0x2f0 > [amdgpu] > [Thu Oct 17 16:43:37 2019] process_termination_cpsch+0x24/0x2f0 > [amdgpu] > [Thu Oct 17 16:43:37 2019] > kfd_process_dequeue_from_all_devices+0x42/0x60 [amdgpu] > [Thu Oct 17 16:43:37 2019] kfd_process_notifier_release+0x1be/0x220 > [amdgpu] > [Thu Oct 17 16:43:37 2019] __mmu_notifier_release+0x3e/0xc0 > [Thu Oct 17 16:43:37 2019] exit_mmap+0x160/0x1a0 > [Thu Oct 17 16:43:37 2019] ? __handle_mm_fault+0xba3/0x1200 > [Thu Oct 17 16:43:37 2019] ? exit_robust_list+0x5a/0x110 > [Thu Oct 17 16:43:37 2019] mmput+0x4a/0x120 > [Thu Oct 17 16:43:37 2019] do_exit+0x284/0xb20 > [Thu Oct 17 16:43:37 2019] ? handle_mm_fault+0xfa/0x200 > [Thu Oct 17 16:43:37 2019] do_group_exit+0x3a/0xa0 > [Thu Oct 17 16:43:37 2019] __x64_sys_exit_group+0x14/0x20 > [Thu Oct 17 16:43:37 2019] do_syscall_64+0x4f/0x100 > [Thu Oct 17 16:43:37 2019] entry_SYSCALL_64_after_hwframe+0x44/0xa9 > > Suggested-by: Felix Kuehling <Felix.Kuehling@xxxxxxx> > Signed-off-by: Philip Yang <Philip.Yang@xxxxxxx> > --- > drivers/gpu/drm/amd/amdkfd/kfd_chardev.c | 6 +-- > drivers/gpu/drm/amd/amdkfd/kfd_device.c | 5 -- > .../drm/amd/amdkfd/kfd_device_queue_manager.c | 47 +++++++++++++++++-- > .../drm/amd/amdkfd/kfd_device_queue_manager.h | 1 + > 4 files changed, 46 insertions(+), 13 deletions(-) > > diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c > index d9e36dbf13d5..40d75c39f08e 100644 > --- a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c > +++ b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c > @@ -120,13 +120,13 @@ static int kfd_open(struct inode *inode, struct file *filep) > return -EPERM; > } > > + if (kfd_is_locked()) > + return -EAGAIN; > + > process = kfd_create_process(filep); > if (IS_ERR(process)) > return PTR_ERR(process); > > - if (kfd_is_locked()) > - return -EAGAIN; > - > dev_dbg(kfd_device, "process %d opened, compat mode (32 bit) - %d\n", > process->pasid, process->is_32bit_user_mode); > > diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_device.c b/drivers/gpu/drm/amd/amdkfd/kfd_device.c > index 8f4b24e84964..4fa8834ce7cb 100644 > --- a/drivers/gpu/drm/amd/amdkfd/kfd_device.c > +++ b/drivers/gpu/drm/amd/amdkfd/kfd_device.c > @@ -730,9 +730,6 @@ int kgd2kfd_pre_reset(struct kfd_dev *kfd) > return 0; > kgd2kfd_suspend(kfd); > > - /* hold dqm->lock to prevent further execution*/ > - dqm_lock(kfd->dqm); > - > kfd_signal_reset_event(kfd); > return 0; > } > @@ -750,8 +747,6 @@ int kgd2kfd_post_reset(struct kfd_dev *kfd) > if (!kfd->init_complete) > return 0; > > - dqm_unlock(kfd->dqm); > - > ret = kfd_resume(kfd); > if (ret) > return ret; > diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c > index 81fb545cf42c..82e1c6280d13 100644 > --- a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c > +++ b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c > @@ -340,6 +340,10 @@ static int create_queue_nocpsch(struct device_queue_manager *dqm, > mqd_mgr->init_mqd(mqd_mgr, &q->mqd, q->mqd_mem_obj, > &q->gart_mqd_addr, &q->properties); > if (q->properties.is_active) { > + if (!dqm->sched_running) { > + WARN_ONCE(1, "Load non-HWS mqd while stopped\n"); > + goto add_queue_to_list; > + } > > if (WARN(q->process->mm != current->mm, > "should only run in user thread")) > @@ -351,6 +355,7 @@ static int create_queue_nocpsch(struct device_queue_manager *dqm, > goto out_free_mqd; > } > > +add_queue_to_list: > list_add(&q->list, &qpd->queues_list); > qpd->queue_count++; > if (q->properties.is_active) > @@ -458,6 +463,11 @@ static int destroy_queue_nocpsch_locked(struct device_queue_manager *dqm, > > deallocate_doorbell(qpd, q); > > + if (!dqm->sched_running) { > + WARN_ONCE(1, "Destroy non-HWS queue while stopped\n"); > + return 0; > + } > + > retval = mqd_mgr->destroy_mqd(mqd_mgr, q->mqd, > KFD_PREEMPT_TYPE_WAVEFRONT_RESET, > KFD_UNMAP_LATENCY_MS, > @@ -533,6 +543,12 @@ static int update_queue(struct device_queue_manager *dqm, struct queue *q) > (q->properties.type == KFD_QUEUE_TYPE_COMPUTE || > q->properties.type == KFD_QUEUE_TYPE_SDMA || > q->properties.type == KFD_QUEUE_TYPE_SDMA_XGMI)) { > + > + if (!dqm->sched_running) { > + WARN_ONCE(1, "Update non-HWS queue while stopped\n"); > + goto out_unlock; > + } > + > retval = mqd_mgr->destroy_mqd(mqd_mgr, q->mqd, > KFD_PREEMPT_TYPE_WAVEFRONT_DRAIN, > KFD_UNMAP_LATENCY_MS, q->pipe, q->queue); > @@ -602,6 +618,11 @@ static int evict_process_queues_nocpsch(struct device_queue_manager *dqm, > mqd_mgr = dqm->mqd_mgrs[get_mqd_type_from_queue_type( > q->properties.type)]; > q->properties.is_active = false; > + dqm->queue_count--; > + > + if (!dqm->sched_running) > + continue; > + > retval = mqd_mgr->destroy_mqd(mqd_mgr, q->mqd, > KFD_PREEMPT_TYPE_WAVEFRONT_DRAIN, > KFD_UNMAP_LATENCY_MS, q->pipe, q->queue); > @@ -610,7 +631,6 @@ static int evict_process_queues_nocpsch(struct device_queue_manager *dqm, > * maintain a consistent eviction state > */ > ret = retval; > - dqm->queue_count--; > } > > out: > @@ -711,6 +731,11 @@ static int restore_process_queues_nocpsch(struct device_queue_manager *dqm, > mqd_mgr = dqm->mqd_mgrs[get_mqd_type_from_queue_type( > q->properties.type)]; > q->properties.is_active = true; > + dqm->queue_count++; > + > + if (!dqm->sched_running) > + continue; > + > retval = mqd_mgr->load_mqd(mqd_mgr, q->mqd, q->pipe, > q->queue, &q->properties, mm); > if (retval && !ret) > @@ -718,7 +743,6 @@ static int restore_process_queues_nocpsch(struct device_queue_manager *dqm, > * maintain a consistent eviction state > */ > ret = retval; > - dqm->queue_count++; > } > qpd->evicted = 0; > out: > @@ -915,7 +939,8 @@ static int start_nocpsch(struct device_queue_manager *dqm) > > if (dqm->dev->device_info->asic_family == CHIP_HAWAII) > return pm_init(&dqm->packets, dqm); > - > + dqm->sched_running = true; > + > return 0; > } > > @@ -923,7 +948,8 @@ static int stop_nocpsch(struct device_queue_manager *dqm) > { > if (dqm->dev->device_info->asic_family == CHIP_HAWAII) > pm_uninit(&dqm->packets); > - > + dqm->sched_running = false; > + > return 0; > } > > @@ -1074,6 +1100,7 @@ static int start_cpsch(struct device_queue_manager *dqm) > dqm_lock(dqm); > /* clear hang status when driver try to start the hw scheduler */ > dqm->is_hws_hang = false; > + dqm->sched_running = true; > execute_queues_cpsch(dqm, KFD_UNMAP_QUEUES_FILTER_DYNAMIC_QUEUES, 0); > dqm_unlock(dqm); > > @@ -1089,6 +1116,7 @@ static int stop_cpsch(struct device_queue_manager *dqm) > { > dqm_lock(dqm); > unmap_queues_cpsch(dqm, KFD_UNMAP_QUEUES_FILTER_ALL_QUEUES, 0); > + dqm->sched_running = false; > dqm_unlock(dqm); > > kfd_gtt_sa_free(dqm->dev, dqm->fence_mem); > @@ -1275,9 +1303,10 @@ static int map_queues_cpsch(struct device_queue_manager *dqm) > { > int retval; > > + if (!dqm->sched_running) > + return 0; > if (dqm->queue_count <= 0 || dqm->processes_count <= 0) > return 0; > - > if (dqm->active_runlist) > return 0; > > @@ -1299,6 +1328,8 @@ static int unmap_queues_cpsch(struct device_queue_manager *dqm, > { > int retval = 0; > > + if (!dqm->sched_running) > + return 0; > if (dqm->is_hws_hang) > return -EIO; > if (!dqm->active_runlist) > @@ -1903,6 +1934,12 @@ int dqm_debugfs_hqds(struct seq_file *m, void *data) > int pipe, queue; > int r = 0; > > + if (!dqm->sched_running) { > + seq_printf(m, " Device is stopped\n"); > + > + return 0; > + } > + > r = dqm->dev->kfd2kgd->hqd_dump(dqm->dev->kgd, > KFD_CIK_HIQ_PIPE, KFD_CIK_HIQ_QUEUE, > &dump, &n_regs); > diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.h b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.h > index 2eaea6b04cbe..a8c37e6da027 100644 > --- a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.h > +++ b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.h > @@ -201,6 +201,7 @@ struct device_queue_manager { > bool is_hws_hang; > struct work_struct hw_exception_work; > struct kfd_mem_obj hiq_sdma_mqd; > + bool sched_running; > }; > > void device_queue_manager_init_cik( _______________________________________________ amd-gfx mailing list amd-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/amd-gfx