From 2c99a547bcf9bb8532abd2953479949018449f93 Mon Sep 17 00:00:00 2001 From: Philip Yang Date: Fri, 18 Oct 2019 10:15:21 -0400 Subject: [PATCH] drm/amdkfd: don't use dqm lock during device reset/suspend/resume 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->sched_running 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 sched_running flag before sending the updated runlist. 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 Signed-off-by: Philip Yang Reviewed-by: Felix Kuehling Signed-off-by: Alex Deucher --- 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 + 3 files changed, 43 insertions(+), 10 deletions(-) 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..984c2f2b24b6 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 (WARN_ONCE(!dqm->sched_running, "Evict when stopped\n")) + 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 (WARN_ONCE(!dqm->sched_running, "Restore when stopped\n")) + 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( -- 2.45.2