From: Tvrtko Ursulin tvrtko.ursulin@igalia.com
As commit 746ae46c1113 ("drm/sched: Mark scheduler work queues with WQ_MEM_RECLAIM") points out, ever since a6149f039369 ("drm/sched: Convert drm scheduler to use a work queue rather than kthread"), any workqueue flushing done from the job submission path must only involve memory reclaim safe workqueues to be safe against reclaim deadlocks.
This is also pointed out by workqueue sanity checks:
[ ] workqueue: WQ_MEM_RECLAIM sdma0:drm_sched_run_job_work [gpu_sched] is flushing !WQ_MEM_RECLAIM events:amdgpu_device_delay_enable_gfx_off [amdgpu] ... [ ] Workqueue: sdma0 drm_sched_run_job_work [gpu_sched] ... [ ] Call Trace: [ ] <TASK> ... [ ] ? check_flush_dependency+0xf5/0x110 ... [ ] cancel_delayed_work_sync+0x6e/0x80 [ ] amdgpu_gfx_off_ctrl+0xab/0x140 [amdgpu] [ ] amdgpu_ring_alloc+0x40/0x50 [amdgpu] [ ] amdgpu_ib_schedule+0xf4/0x810 [amdgpu] [ ] ? drm_sched_run_job_work+0x22c/0x430 [gpu_sched] [ ] amdgpu_job_run+0xaa/0x1f0 [amdgpu] [ ] drm_sched_run_job_work+0x257/0x430 [gpu_sched] [ ] process_one_work+0x217/0x720 ... [ ] </TASK>
Fix this by creating a memory reclaim safe driver workqueue and make the submission path use it.
Signed-off-by: Tvrtko Ursulin tvrtko.ursulin@igalia.com References: 746ae46c1113 ("drm/sched: Mark scheduler work queues with WQ_MEM_RECLAIM") Fixes: a6149f039369 ("drm/sched: Convert drm scheduler to use a work queue rather than kthread") Cc: stable@vger.kernel.org Cc: Matthew Brost matthew.brost@intel.com Cc: Danilo Krummrich dakr@kernel.org Cc: Philipp Stanner pstanner@redhat.com Cc: Alex Deucher alexander.deucher@amd.com Cc: Christian König christian.koenig@amd.com --- drivers/gpu/drm/amd/amdgpu/amdgpu.h | 2 ++ drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c | 25 +++++++++++++++++++++++++ drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c | 5 +++-- 3 files changed, 30 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h index 7645e498faa4..a6aad687537e 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h @@ -268,6 +268,8 @@ extern int amdgpu_agp;
extern int amdgpu_wbrf;
+extern struct workqueue_struct *amdgpu_reclaim_wq; + #define AMDGPU_VM_MAX_NUM_CTX 4096 #define AMDGPU_SG_THRESHOLD (256*1024*1024) #define AMDGPU_WAIT_IDLE_TIMEOUT_IN_MS 3000 diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c index 38686203bea6..f5b7172e8042 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c @@ -255,6 +255,8 @@ struct amdgpu_watchdog_timer amdgpu_watchdog_timer = { .period = 0x0, /* default to 0x0 (timeout disable) */ };
+struct workqueue_struct *amdgpu_reclaim_wq; + /** * DOC: vramlimit (int) * Restrict the total amount of VRAM in MiB for testing. The default is 0 (Use full VRAM). @@ -2971,6 +2973,21 @@ static struct pci_driver amdgpu_kms_pci_driver = { .dev_groups = amdgpu_sysfs_groups, };
+static int amdgpu_wq_init(void) +{ + amdgpu_reclaim_wq = + alloc_workqueue("amdgpu-reclaim", WQ_MEM_RECLAIM, 0); + if (!amdgpu_reclaim_wq) + return -ENOMEM; + + return 0; +} + +static void amdgpu_wq_fini(void) +{ + destroy_workqueue(amdgpu_reclaim_wq); +} + static int __init amdgpu_init(void) { int r; @@ -2978,6 +2995,10 @@ static int __init amdgpu_init(void) if (drm_firmware_drivers_only()) return -EINVAL;
+ r = amdgpu_wq_init(); + if (r) + goto error_wq; + r = amdgpu_sync_init(); if (r) goto error_sync; @@ -3006,6 +3027,9 @@ static int __init amdgpu_init(void) amdgpu_sync_fini();
error_sync: + amdgpu_wq_fini(); + +error_wq: return r; }
@@ -3017,6 +3041,7 @@ static void __exit amdgpu_exit(void) amdgpu_acpi_release(); amdgpu_sync_fini(); amdgpu_fence_slab_fini(); + amdgpu_wq_fini(); mmu_notifier_synchronize(); amdgpu_xcp_drv_release(); } diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c index 2f3f09dfb1fd..f8fd71d9382f 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c @@ -790,8 +790,9 @@ void amdgpu_gfx_off_ctrl(struct amdgpu_device *adev, bool enable) AMD_IP_BLOCK_TYPE_GFX, true)) adev->gfx.gfx_off_state = true; } else { - schedule_delayed_work(&adev->gfx.gfx_off_delay_work, - delay); + queue_delayed_work(amdgpu_reclaim_wq, + &adev->gfx.gfx_off_delay_work, + delay); } } } else {
Am 13.11.24 um 14:48 schrieb Tvrtko Ursulin:
From: Tvrtko Ursulin tvrtko.ursulin@igalia.com
As commit 746ae46c1113 ("drm/sched: Mark scheduler work queues with WQ_MEM_RECLAIM") points out, ever since a6149f039369 ("drm/sched: Convert drm scheduler to use a work queue rather than kthread"), any workqueue flushing done from the job submission path must only involve memory reclaim safe workqueues to be safe against reclaim deadlocks.
This is also pointed out by workqueue sanity checks:
[ ] workqueue: WQ_MEM_RECLAIM sdma0:drm_sched_run_job_work [gpu_sched] is flushing !WQ_MEM_RECLAIM events:amdgpu_device_delay_enable_gfx_off [amdgpu] ... [ ] Workqueue: sdma0 drm_sched_run_job_work [gpu_sched] ... [ ] Call Trace: [ ] <TASK> ... [ ] ? check_flush_dependency+0xf5/0x110 ... [ ] cancel_delayed_work_sync+0x6e/0x80 [ ] amdgpu_gfx_off_ctrl+0xab/0x140 [amdgpu] [ ] amdgpu_ring_alloc+0x40/0x50 [amdgpu] [ ] amdgpu_ib_schedule+0xf4/0x810 [amdgpu] [ ] ? drm_sched_run_job_work+0x22c/0x430 [gpu_sched] [ ] amdgpu_job_run+0xaa/0x1f0 [amdgpu] [ ] drm_sched_run_job_work+0x257/0x430 [gpu_sched] [ ] process_one_work+0x217/0x720 ... [ ] </TASK>
Fix this by creating a memory reclaim safe driver workqueue and make the submission path use it.
Oh well, that is a really good catch! I wasn't aware the workqueues could be blocked by memory reclaim as well.
Do we have system wide workqueues for that? It seems a bit overkill that amdgpu has to allocate one on his own.
Apart from that looks good to me.
Regards, Christian.
Signed-off-by: Tvrtko Ursulin tvrtko.ursulin@igalia.com References: 746ae46c1113 ("drm/sched: Mark scheduler work queues with WQ_MEM_RECLAIM") Fixes: a6149f039369 ("drm/sched: Convert drm scheduler to use a work queue rather than kthread") Cc: stable@vger.kernel.org Cc: Matthew Brost matthew.brost@intel.com Cc: Danilo Krummrich dakr@kernel.org Cc: Philipp Stanner pstanner@redhat.com Cc: Alex Deucher alexander.deucher@amd.com Cc: Christian König christian.koenig@amd.com
drivers/gpu/drm/amd/amdgpu/amdgpu.h | 2 ++ drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c | 25 +++++++++++++++++++++++++ drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c | 5 +++-- 3 files changed, 30 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h index 7645e498faa4..a6aad687537e 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h @@ -268,6 +268,8 @@ extern int amdgpu_agp; extern int amdgpu_wbrf; +extern struct workqueue_struct *amdgpu_reclaim_wq;
- #define AMDGPU_VM_MAX_NUM_CTX 4096 #define AMDGPU_SG_THRESHOLD (256*1024*1024) #define AMDGPU_WAIT_IDLE_TIMEOUT_IN_MS 3000
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c index 38686203bea6..f5b7172e8042 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c @@ -255,6 +255,8 @@ struct amdgpu_watchdog_timer amdgpu_watchdog_timer = { .period = 0x0, /* default to 0x0 (timeout disable) */ }; +struct workqueue_struct *amdgpu_reclaim_wq;
- /**
- DOC: vramlimit (int)
- Restrict the total amount of VRAM in MiB for testing. The default is 0 (Use full VRAM).
@@ -2971,6 +2973,21 @@ static struct pci_driver amdgpu_kms_pci_driver = { .dev_groups = amdgpu_sysfs_groups, }; +static int amdgpu_wq_init(void) +{
- amdgpu_reclaim_wq =
alloc_workqueue("amdgpu-reclaim", WQ_MEM_RECLAIM, 0);- if (!amdgpu_reclaim_wq)
return -ENOMEM;- return 0;
+}
+static void amdgpu_wq_fini(void) +{
- destroy_workqueue(amdgpu_reclaim_wq);
+}
- static int __init amdgpu_init(void) { int r;
@@ -2978,6 +2995,10 @@ static int __init amdgpu_init(void) if (drm_firmware_drivers_only()) return -EINVAL;
- r = amdgpu_wq_init();
- if (r)
goto error_wq;- r = amdgpu_sync_init(); if (r) goto error_sync;
@@ -3006,6 +3027,9 @@ static int __init amdgpu_init(void) amdgpu_sync_fini(); error_sync:
- amdgpu_wq_fini();
+error_wq: return r; } @@ -3017,6 +3041,7 @@ static void __exit amdgpu_exit(void) amdgpu_acpi_release(); amdgpu_sync_fini(); amdgpu_fence_slab_fini();
- amdgpu_wq_fini(); mmu_notifier_synchronize(); amdgpu_xcp_drv_release(); }
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c index 2f3f09dfb1fd..f8fd71d9382f 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c @@ -790,8 +790,9 @@ void amdgpu_gfx_off_ctrl(struct amdgpu_device *adev, bool enable) AMD_IP_BLOCK_TYPE_GFX, true)) adev->gfx.gfx_off_state = true; } else {
schedule_delayed_work(&adev->gfx.gfx_off_delay_work,delay);
queue_delayed_work(amdgpu_reclaim_wq,&adev->gfx.gfx_off_delay_work,delay); }
On 13/11/2024 14:26, Christian König wrote:
Am 13.11.24 um 14:48 schrieb Tvrtko Ursulin:
From: Tvrtko Ursulin tvrtko.ursulin@igalia.com
As commit 746ae46c1113 ("drm/sched: Mark scheduler work queues with WQ_MEM_RECLAIM") points out, ever since a6149f039369 ("drm/sched: Convert drm scheduler to use a work queue rather than kthread"), any workqueue flushing done from the job submission path must only involve memory reclaim safe workqueues to be safe against reclaim deadlocks.
This is also pointed out by workqueue sanity checks:
[ ] workqueue: WQ_MEM_RECLAIM sdma0:drm_sched_run_job_work [gpu_sched] is flushing !WQ_MEM_RECLAIM events:amdgpu_device_delay_enable_gfx_off [amdgpu] ... [ ] Workqueue: sdma0 drm_sched_run_job_work [gpu_sched] ... [ ] Call Trace: [ ] <TASK> ... [ ] ? check_flush_dependency+0xf5/0x110 ... [ ] cancel_delayed_work_sync+0x6e/0x80 [ ] amdgpu_gfx_off_ctrl+0xab/0x140 [amdgpu] [ ] amdgpu_ring_alloc+0x40/0x50 [amdgpu] [ ] amdgpu_ib_schedule+0xf4/0x810 [amdgpu] [ ] ? drm_sched_run_job_work+0x22c/0x430 [gpu_sched] [ ] amdgpu_job_run+0xaa/0x1f0 [amdgpu] [ ] drm_sched_run_job_work+0x257/0x430 [gpu_sched] [ ] process_one_work+0x217/0x720 ... [ ] </TASK>
Fix this by creating a memory reclaim safe driver workqueue and make the submission path use it.
Oh well, that is a really good catch! I wasn't aware the workqueues could be blocked by memory reclaim as well.
Only credit I can take is for the habit that I often run with many kernel debugging aids enabled.
Do we have system wide workqueues for that? It seems a bit overkill that amdgpu has to allocate one on his own.
I wondered the same but did not find any. Only ones I am aware of are system_wq&co created in workqueue_init_early().
Regards,
Tvrtko
Apart from that looks good to me.
Regards, Christian.
Signed-off-by: Tvrtko Ursulin tvrtko.ursulin@igalia.com References: 746ae46c1113 ("drm/sched: Mark scheduler work queues with WQ_MEM_RECLAIM") Fixes: a6149f039369 ("drm/sched: Convert drm scheduler to use a work queue rather than kthread") Cc: stable@vger.kernel.org Cc: Matthew Brost matthew.brost@intel.com Cc: Danilo Krummrich dakr@kernel.org Cc: Philipp Stanner pstanner@redhat.com Cc: Alex Deucher alexander.deucher@amd.com Cc: Christian König christian.koenig@amd.com
drivers/gpu/drm/amd/amdgpu/amdgpu.h | 2 ++ drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c | 25 +++++++++++++++++++++++++ drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c | 5 +++-- 3 files changed, 30 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h index 7645e498faa4..a6aad687537e 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h @@ -268,6 +268,8 @@ extern int amdgpu_agp; extern int amdgpu_wbrf; +extern struct workqueue_struct *amdgpu_reclaim_wq;
#define AMDGPU_VM_MAX_NUM_CTX 4096 #define AMDGPU_SG_THRESHOLD (256*1024*1024) #define AMDGPU_WAIT_IDLE_TIMEOUT_IN_MS 3000 diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c index 38686203bea6..f5b7172e8042 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c @@ -255,6 +255,8 @@ struct amdgpu_watchdog_timer amdgpu_watchdog_timer = { .period = 0x0, /* default to 0x0 (timeout disable) */ }; +struct workqueue_struct *amdgpu_reclaim_wq;
/** * DOC: vramlimit (int) * Restrict the total amount of VRAM in MiB for testing. The default is 0 (Use full VRAM). @@ -2971,6 +2973,21 @@ static struct pci_driver amdgpu_kms_pci_driver = { .dev_groups = amdgpu_sysfs_groups, }; +static int amdgpu_wq_init(void) +{ + amdgpu_reclaim_wq = + alloc_workqueue("amdgpu-reclaim", WQ_MEM_RECLAIM, 0); + if (!amdgpu_reclaim_wq) + return -ENOMEM;
+ return 0; +}
+static void amdgpu_wq_fini(void) +{ + destroy_workqueue(amdgpu_reclaim_wq); +}
static int __init amdgpu_init(void) { int r; @@ -2978,6 +2995,10 @@ static int __init amdgpu_init(void) if (drm_firmware_drivers_only()) return -EINVAL; + r = amdgpu_wq_init(); + if (r) + goto error_wq;
r = amdgpu_sync_init(); if (r) goto error_sync; @@ -3006,6 +3027,9 @@ static int __init amdgpu_init(void) amdgpu_sync_fini(); error_sync: + amdgpu_wq_fini();
+error_wq: return r; } @@ -3017,6 +3041,7 @@ static void __exit amdgpu_exit(void) amdgpu_acpi_release(); amdgpu_sync_fini(); amdgpu_fence_slab_fini(); + amdgpu_wq_fini(); mmu_notifier_synchronize(); amdgpu_xcp_drv_release(); } diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c index 2f3f09dfb1fd..f8fd71d9382f 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c @@ -790,8 +790,9 @@ void amdgpu_gfx_off_ctrl(struct amdgpu_device *adev, bool enable) AMD_IP_BLOCK_TYPE_GFX, true)) adev->gfx.gfx_off_state = true; } else { - schedule_delayed_work(&adev->gfx.gfx_off_delay_work, - delay); + queue_delayed_work(amdgpu_reclaim_wq, + &adev->gfx.gfx_off_delay_work, + delay); } } } else {
On 13/11/2024 14:42, Tvrtko Ursulin wrote:
On 13/11/2024 14:26, Christian König wrote:
Am 13.11.24 um 14:48 schrieb Tvrtko Ursulin:
From: Tvrtko Ursulin tvrtko.ursulin@igalia.com
As commit 746ae46c1113 ("drm/sched: Mark scheduler work queues with WQ_MEM_RECLAIM") points out, ever since a6149f039369 ("drm/sched: Convert drm scheduler to use a work queue rather than kthread"), any workqueue flushing done from the job submission path must only involve memory reclaim safe workqueues to be safe against reclaim deadlocks.
This is also pointed out by workqueue sanity checks:
[ ] workqueue: WQ_MEM_RECLAIM sdma0:drm_sched_run_job_work [gpu_sched] is flushing !WQ_MEM_RECLAIM events:amdgpu_device_delay_enable_gfx_off [amdgpu] ... [ ] Workqueue: sdma0 drm_sched_run_job_work [gpu_sched] ... [ ] Call Trace: [ ] <TASK> ... [ ] ? check_flush_dependency+0xf5/0x110 ... [ ] cancel_delayed_work_sync+0x6e/0x80 [ ] amdgpu_gfx_off_ctrl+0xab/0x140 [amdgpu] [ ] amdgpu_ring_alloc+0x40/0x50 [amdgpu] [ ] amdgpu_ib_schedule+0xf4/0x810 [amdgpu] [ ] ? drm_sched_run_job_work+0x22c/0x430 [gpu_sched] [ ] amdgpu_job_run+0xaa/0x1f0 [amdgpu] [ ] drm_sched_run_job_work+0x257/0x430 [gpu_sched] [ ] process_one_work+0x217/0x720 ... [ ] </TASK>
Fix this by creating a memory reclaim safe driver workqueue and make the submission path use it.
Oh well, that is a really good catch! I wasn't aware the workqueues could be blocked by memory reclaim as well.
Only credit I can take is for the habit that I often run with many kernel debugging aids enabled.
Although this one actually isn't even under "Kernel hacking".
Do we have system wide workqueues for that? It seems a bit overkill that amdgpu has to allocate one on his own.
I wondered the same but did not find any. Only ones I am aware of are system_wq&co created in workqueue_init_early().
Gentle ping on this. I don't have any better ideas that creating a new wq.
Regards,
Tvrtko
Apart from that looks good to me.
Regards, Christian.
Signed-off-by: Tvrtko Ursulin tvrtko.ursulin@igalia.com References: 746ae46c1113 ("drm/sched: Mark scheduler work queues with WQ_MEM_RECLAIM") Fixes: a6149f039369 ("drm/sched: Convert drm scheduler to use a work queue rather than kthread") Cc: stable@vger.kernel.org Cc: Matthew Brost matthew.brost@intel.com Cc: Danilo Krummrich dakr@kernel.org Cc: Philipp Stanner pstanner@redhat.com Cc: Alex Deucher alexander.deucher@amd.com Cc: Christian König christian.koenig@amd.com
drivers/gpu/drm/amd/amdgpu/amdgpu.h | 2 ++ drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c | 25 +++++++++++++++++++++++++ drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c | 5 +++-- 3 files changed, 30 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h index 7645e498faa4..a6aad687537e 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h @@ -268,6 +268,8 @@ extern int amdgpu_agp; extern int amdgpu_wbrf; +extern struct workqueue_struct *amdgpu_reclaim_wq;
#define AMDGPU_VM_MAX_NUM_CTX 4096 #define AMDGPU_SG_THRESHOLD (256*1024*1024) #define AMDGPU_WAIT_IDLE_TIMEOUT_IN_MS 3000 diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c index 38686203bea6..f5b7172e8042 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c @@ -255,6 +255,8 @@ struct amdgpu_watchdog_timer amdgpu_watchdog_timer = { .period = 0x0, /* default to 0x0 (timeout disable) */ }; +struct workqueue_struct *amdgpu_reclaim_wq;
/** * DOC: vramlimit (int) * Restrict the total amount of VRAM in MiB for testing. The default is 0 (Use full VRAM). @@ -2971,6 +2973,21 @@ static struct pci_driver amdgpu_kms_pci_driver = { .dev_groups = amdgpu_sysfs_groups, }; +static int amdgpu_wq_init(void) +{ + amdgpu_reclaim_wq = + alloc_workqueue("amdgpu-reclaim", WQ_MEM_RECLAIM, 0); + if (!amdgpu_reclaim_wq) + return -ENOMEM;
+ return 0; +}
+static void amdgpu_wq_fini(void) +{ + destroy_workqueue(amdgpu_reclaim_wq); +}
static int __init amdgpu_init(void) { int r; @@ -2978,6 +2995,10 @@ static int __init amdgpu_init(void) if (drm_firmware_drivers_only()) return -EINVAL; + r = amdgpu_wq_init(); + if (r) + goto error_wq;
r = amdgpu_sync_init(); if (r) goto error_sync; @@ -3006,6 +3027,9 @@ static int __init amdgpu_init(void) amdgpu_sync_fini(); error_sync: + amdgpu_wq_fini();
+error_wq: return r; } @@ -3017,6 +3041,7 @@ static void __exit amdgpu_exit(void) amdgpu_acpi_release(); amdgpu_sync_fini(); amdgpu_fence_slab_fini(); + amdgpu_wq_fini(); mmu_notifier_synchronize(); amdgpu_xcp_drv_release(); } diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c index 2f3f09dfb1fd..f8fd71d9382f 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c @@ -790,8 +790,9 @@ void amdgpu_gfx_off_ctrl(struct amdgpu_device *adev, bool enable) AMD_IP_BLOCK_TYPE_GFX, true)) adev->gfx.gfx_off_state = true; } else { - schedule_delayed_work(&adev->gfx.gfx_off_delay_work, - delay); + queue_delayed_work(amdgpu_reclaim_wq, + &adev->gfx.gfx_off_delay_work, + delay); } } } else {
Am 22.11.24 um 12:34 schrieb Tvrtko Ursulin:
On 13/11/2024 14:42, Tvrtko Ursulin wrote:
On 13/11/2024 14:26, Christian König wrote:
Am 13.11.24 um 14:48 schrieb Tvrtko Ursulin:
From: Tvrtko Ursulin tvrtko.ursulin@igalia.com
As commit 746ae46c1113 ("drm/sched: Mark scheduler work queues with WQ_MEM_RECLAIM") points out, ever since a6149f039369 ("drm/sched: Convert drm scheduler to use a work queue rather than kthread"), any workqueue flushing done from the job submission path must only involve memory reclaim safe workqueues to be safe against reclaim deadlocks.
This is also pointed out by workqueue sanity checks:
[ ] workqueue: WQ_MEM_RECLAIM sdma0:drm_sched_run_job_work [gpu_sched] is flushing !WQ_MEM_RECLAIM events:amdgpu_device_delay_enable_gfx_off [amdgpu] ... [ ] Workqueue: sdma0 drm_sched_run_job_work [gpu_sched] ... [ ] Call Trace: [ ] <TASK> ... [ ] ? check_flush_dependency+0xf5/0x110 ... [ ] cancel_delayed_work_sync+0x6e/0x80 [ ] amdgpu_gfx_off_ctrl+0xab/0x140 [amdgpu] [ ] amdgpu_ring_alloc+0x40/0x50 [amdgpu] [ ] amdgpu_ib_schedule+0xf4/0x810 [amdgpu] [ ] ? drm_sched_run_job_work+0x22c/0x430 [gpu_sched] [ ] amdgpu_job_run+0xaa/0x1f0 [amdgpu] [ ] drm_sched_run_job_work+0x257/0x430 [gpu_sched] [ ] process_one_work+0x217/0x720 ... [ ] </TASK>
Fix this by creating a memory reclaim safe driver workqueue and make the submission path use it.
Oh well, that is a really good catch! I wasn't aware the workqueues could be blocked by memory reclaim as well.
Only credit I can take is for the habit that I often run with many kernel debugging aids enabled.
Although this one actually isn't even under "Kernel hacking".
Do we have system wide workqueues for that? It seems a bit overkill that amdgpu has to allocate one on his own.
I wondered the same but did not find any. Only ones I am aware of are system_wq&co created in workqueue_init_early().
Gentle ping on this. I don't have any better ideas that creating a new wq.
It took me a moment to realize, but I now think this warning message is a false positive.
What happens is that the code calls cancel_delayed_work_sync().
If the work item never run because of lack of memory then it can just be canceled.
If the work item is running then we will block for it to finish.
There is no need to use WQ_MEM_RECLAIM for the workqueue or do I miss something?
If I'm not completely mistaken you stumbled over a bug in the warning code instead :)
Regards, Christian.
Regards,
Tvrtko
Apart from that looks good to me.
Regards, Christian.
Signed-off-by: Tvrtko Ursulin tvrtko.ursulin@igalia.com References: 746ae46c1113 ("drm/sched: Mark scheduler work queues with WQ_MEM_RECLAIM") Fixes: a6149f039369 ("drm/sched: Convert drm scheduler to use a work queue rather than kthread") Cc: stable@vger.kernel.org Cc: Matthew Brost matthew.brost@intel.com Cc: Danilo Krummrich dakr@kernel.org Cc: Philipp Stanner pstanner@redhat.com Cc: Alex Deucher alexander.deucher@amd.com Cc: Christian König christian.koenig@amd.com
drivers/gpu/drm/amd/amdgpu/amdgpu.h | 2 ++ drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c | 25 +++++++++++++++++++++++++ drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c | 5 +++-- 3 files changed, 30 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h index 7645e498faa4..a6aad687537e 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h @@ -268,6 +268,8 @@ extern int amdgpu_agp; extern int amdgpu_wbrf; +extern struct workqueue_struct *amdgpu_reclaim_wq;
#define AMDGPU_VM_MAX_NUM_CTX 4096 #define AMDGPU_SG_THRESHOLD (256*1024*1024) #define AMDGPU_WAIT_IDLE_TIMEOUT_IN_MS 3000 diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c index 38686203bea6..f5b7172e8042 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c @@ -255,6 +255,8 @@ struct amdgpu_watchdog_timer amdgpu_watchdog_timer = { .period = 0x0, /* default to 0x0 (timeout disable) */ }; +struct workqueue_struct *amdgpu_reclaim_wq;
/** * DOC: vramlimit (int) * Restrict the total amount of VRAM in MiB for testing. The default is 0 (Use full VRAM). @@ -2971,6 +2973,21 @@ static struct pci_driver amdgpu_kms_pci_driver = { .dev_groups = amdgpu_sysfs_groups, }; +static int amdgpu_wq_init(void) +{ + amdgpu_reclaim_wq = + alloc_workqueue("amdgpu-reclaim", WQ_MEM_RECLAIM, 0); + if (!amdgpu_reclaim_wq) + return -ENOMEM;
+ return 0; +}
+static void amdgpu_wq_fini(void) +{ + destroy_workqueue(amdgpu_reclaim_wq); +}
static int __init amdgpu_init(void) { int r; @@ -2978,6 +2995,10 @@ static int __init amdgpu_init(void) if (drm_firmware_drivers_only()) return -EINVAL; + r = amdgpu_wq_init(); + if (r) + goto error_wq;
r = amdgpu_sync_init(); if (r) goto error_sync; @@ -3006,6 +3027,9 @@ static int __init amdgpu_init(void) amdgpu_sync_fini(); error_sync: + amdgpu_wq_fini();
+error_wq: return r; } @@ -3017,6 +3041,7 @@ static void __exit amdgpu_exit(void) amdgpu_acpi_release(); amdgpu_sync_fini(); amdgpu_fence_slab_fini(); + amdgpu_wq_fini(); mmu_notifier_synchronize(); amdgpu_xcp_drv_release(); } diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c index 2f3f09dfb1fd..f8fd71d9382f 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c @@ -790,8 +790,9 @@ void amdgpu_gfx_off_ctrl(struct amdgpu_device *adev, bool enable) AMD_IP_BLOCK_TYPE_GFX, true)) adev->gfx.gfx_off_state = true; } else {
- schedule_delayed_work(&adev->gfx.gfx_off_delay_work,
- delay); + queue_delayed_work(amdgpu_reclaim_wq,
- &adev->gfx.gfx_off_delay_work,
+ delay); } } } else {
On 22/11/2024 13:46, Christian König wrote:
Am 22.11.24 um 12:34 schrieb Tvrtko Ursulin:
On 13/11/2024 14:42, Tvrtko Ursulin wrote:
On 13/11/2024 14:26, Christian König wrote:
Am 13.11.24 um 14:48 schrieb Tvrtko Ursulin:
From: Tvrtko Ursulin tvrtko.ursulin@igalia.com
As commit 746ae46c1113 ("drm/sched: Mark scheduler work queues with WQ_MEM_RECLAIM") points out, ever since a6149f039369 ("drm/sched: Convert drm scheduler to use a work queue rather than kthread"), any workqueue flushing done from the job submission path must only involve memory reclaim safe workqueues to be safe against reclaim deadlocks.
This is also pointed out by workqueue sanity checks:
[ ] workqueue: WQ_MEM_RECLAIM sdma0:drm_sched_run_job_work [gpu_sched] is flushing !WQ_MEM_RECLAIM events:amdgpu_device_delay_enable_gfx_off [amdgpu] ... [ ] Workqueue: sdma0 drm_sched_run_job_work [gpu_sched] ... [ ] Call Trace: [ ] <TASK> ... [ ] ? check_flush_dependency+0xf5/0x110 ... [ ] cancel_delayed_work_sync+0x6e/0x80 [ ] amdgpu_gfx_off_ctrl+0xab/0x140 [amdgpu] [ ] amdgpu_ring_alloc+0x40/0x50 [amdgpu] [ ] amdgpu_ib_schedule+0xf4/0x810 [amdgpu] [ ] ? drm_sched_run_job_work+0x22c/0x430 [gpu_sched] [ ] amdgpu_job_run+0xaa/0x1f0 [amdgpu] [ ] drm_sched_run_job_work+0x257/0x430 [gpu_sched] [ ] process_one_work+0x217/0x720 ... [ ] </TASK>
Fix this by creating a memory reclaim safe driver workqueue and make the submission path use it.
Oh well, that is a really good catch! I wasn't aware the workqueues could be blocked by memory reclaim as well.
Only credit I can take is for the habit that I often run with many kernel debugging aids enabled.
Although this one actually isn't even under "Kernel hacking".
Do we have system wide workqueues for that? It seems a bit overkill that amdgpu has to allocate one on his own.
I wondered the same but did not find any. Only ones I am aware of are system_wq&co created in workqueue_init_early().
Gentle ping on this. I don't have any better ideas that creating a new wq.
It took me a moment to realize, but I now think this warning message is a false positive.
What happens is that the code calls cancel_delayed_work_sync().
If the work item never run because of lack of memory then it can just be canceled.
If the work item is running then we will block for it to finish.
There is no need to use WQ_MEM_RECLAIM for the workqueue or do I miss something?
If I'm not completely mistaken you stumbled over a bug in the warning code instead :)
Hmm your thinking sounds convincing.
Adding Tejun if he has time to help brainstorm this.
Question is - does check_flush_dependency() need to skip the !WQ_MEM_RECLAIM flushing WQ_MEM_RECLAIM warning *if* the work is already running *and* it was called from cancel_delayed_work_sync()?
Regards,
Tvrtko
Apart from that looks good to me.
Regards, Christian.
Signed-off-by: Tvrtko Ursulin tvrtko.ursulin@igalia.com References: 746ae46c1113 ("drm/sched: Mark scheduler work queues with WQ_MEM_RECLAIM") Fixes: a6149f039369 ("drm/sched: Convert drm scheduler to use a work queue rather than kthread") Cc: stable@vger.kernel.org Cc: Matthew Brost matthew.brost@intel.com Cc: Danilo Krummrich dakr@kernel.org Cc: Philipp Stanner pstanner@redhat.com Cc: Alex Deucher alexander.deucher@amd.com Cc: Christian König christian.koenig@amd.com
drivers/gpu/drm/amd/amdgpu/amdgpu.h | 2 ++ drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c | 25 +++++++++++++++++++++++++ drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c | 5 +++-- 3 files changed, 30 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h index 7645e498faa4..a6aad687537e 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h @@ -268,6 +268,8 @@ extern int amdgpu_agp; extern int amdgpu_wbrf; +extern struct workqueue_struct *amdgpu_reclaim_wq;
#define AMDGPU_VM_MAX_NUM_CTX 4096 #define AMDGPU_SG_THRESHOLD (256*1024*1024) #define AMDGPU_WAIT_IDLE_TIMEOUT_IN_MS 3000 diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c index 38686203bea6..f5b7172e8042 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c @@ -255,6 +255,8 @@ struct amdgpu_watchdog_timer amdgpu_watchdog_timer = { .period = 0x0, /* default to 0x0 (timeout disable) */ }; +struct workqueue_struct *amdgpu_reclaim_wq;
/** * DOC: vramlimit (int) * Restrict the total amount of VRAM in MiB for testing. The default is 0 (Use full VRAM). @@ -2971,6 +2973,21 @@ static struct pci_driver amdgpu_kms_pci_driver = { .dev_groups = amdgpu_sysfs_groups, }; +static int amdgpu_wq_init(void) +{ + amdgpu_reclaim_wq = + alloc_workqueue("amdgpu-reclaim", WQ_MEM_RECLAIM, 0); + if (!amdgpu_reclaim_wq) + return -ENOMEM;
+ return 0; +}
+static void amdgpu_wq_fini(void) +{ + destroy_workqueue(amdgpu_reclaim_wq); +}
static int __init amdgpu_init(void) { int r; @@ -2978,6 +2995,10 @@ static int __init amdgpu_init(void) if (drm_firmware_drivers_only()) return -EINVAL; + r = amdgpu_wq_init(); + if (r) + goto error_wq;
r = amdgpu_sync_init(); if (r) goto error_sync; @@ -3006,6 +3027,9 @@ static int __init amdgpu_init(void) amdgpu_sync_fini(); error_sync: + amdgpu_wq_fini();
+error_wq: return r; } @@ -3017,6 +3041,7 @@ static void __exit amdgpu_exit(void) amdgpu_acpi_release(); amdgpu_sync_fini(); amdgpu_fence_slab_fini(); + amdgpu_wq_fini(); mmu_notifier_synchronize(); amdgpu_xcp_drv_release(); } diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c index 2f3f09dfb1fd..f8fd71d9382f 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c @@ -790,8 +790,9 @@ void amdgpu_gfx_off_ctrl(struct amdgpu_device *adev, bool enable) AMD_IP_BLOCK_TYPE_GFX, true)) adev->gfx.gfx_off_state = true; } else {
- schedule_delayed_work(&adev->gfx.gfx_off_delay_work,
- delay); + queue_delayed_work(amdgpu_reclaim_wq,
- &adev->gfx.gfx_off_delay_work,
+ delay); } } } else {
On Fri, Nov 22, 2024 at 02:36:59PM +0000, Tvrtko Ursulin wrote:
On 22/11/2024 13:46, Christian König wrote:
Am 22.11.24 um 12:34 schrieb Tvrtko Ursulin:
On 13/11/2024 14:42, Tvrtko Ursulin wrote:
On 13/11/2024 14:26, Christian König wrote:
Am 13.11.24 um 14:48 schrieb Tvrtko Ursulin:
From: Tvrtko Ursulin tvrtko.ursulin@igalia.com
As commit 746ae46c1113 ("drm/sched: Mark scheduler work queues with WQ_MEM_RECLAIM") points out, ever since a6149f039369 ("drm/sched: Convert drm scheduler to use a work queue rather than kthread"), any workqueue flushing done from the job submission path must only involve memory reclaim safe workqueues to be safe against reclaim deadlocks.
This is also pointed out by workqueue sanity checks:
[ ] workqueue: WQ_MEM_RECLAIM sdma0:drm_sched_run_job_work [gpu_sched] is flushing !WQ_MEM_RECLAIM events:amdgpu_device_delay_enable_gfx_off [amdgpu] ... [ ] Workqueue: sdma0 drm_sched_run_job_work [gpu_sched] ... [ ] Call Trace: [ ] <TASK> ... [ ] ? check_flush_dependency+0xf5/0x110 ... [ ] cancel_delayed_work_sync+0x6e/0x80 [ ] amdgpu_gfx_off_ctrl+0xab/0x140 [amdgpu] [ ] amdgpu_ring_alloc+0x40/0x50 [amdgpu] [ ] amdgpu_ib_schedule+0xf4/0x810 [amdgpu] [ ] ? drm_sched_run_job_work+0x22c/0x430 [gpu_sched] [ ] amdgpu_job_run+0xaa/0x1f0 [amdgpu] [ ] drm_sched_run_job_work+0x257/0x430 [gpu_sched] [ ] process_one_work+0x217/0x720 ... [ ] </TASK>
Fix this by creating a memory reclaim safe driver workqueue and make the submission path use it.
Oh well, that is a really good catch! I wasn't aware the workqueues could be blocked by memory reclaim as well.
Only credit I can take is for the habit that I often run with many kernel debugging aids enabled.
Although this one actually isn't even under "Kernel hacking".
Do we have system wide workqueues for that? It seems a bit overkill that amdgpu has to allocate one on his own.
I wondered the same but did not find any. Only ones I am aware of are system_wq&co created in workqueue_init_early().
Gentle ping on this. I don't have any better ideas that creating a new wq.
It took me a moment to realize, but I now think this warning message is a false positive.
What happens is that the code calls cancel_delayed_work_sync().
If the work item never run because of lack of memory then it can just be canceled.
If the work item is running then we will block for it to finish.
Apologies for the late reply. Alex responded to another thread and CC'd me, which reminded me to reply here.
The execution of the non-reclaim worker could have led to a few scenarios:
- It might have triggered reclaim through its own memory allocation. - It could have been running and then context-switched out, with reclaim being triggered elsewhere in the mean time, pausing the execution of the non-reclaim worker.
In either case, during reclaim, if you wait on a DMA fence that depends on the DRM scheduler worker, and that worker attempts to flush the above non-reclaim worker, it will result in a deadlock.
The annotation appears correct to me, and I believe Tvrtko's patch is indeed accurate. For what it's worth, we encountered several similar bugs in Xe that emerged once we added the correct work queue annotations.
There is no need to use WQ_MEM_RECLAIM for the workqueue or do I miss something?
If I'm not completely mistaken you stumbled over a bug in the warning code instead :)
Hmm your thinking sounds convincing.
Adding Tejun if he has time to help brainstorm this.
Tejun could likely provide insight into whether my above assessment is correct.
Matt
Question is - does check_flush_dependency() need to skip the !WQ_MEM_RECLAIM flushing WQ_MEM_RECLAIM warning *if* the work is already running *and* it was called from cancel_delayed_work_sync()?
Regards,
Tvrtko
Apart from that looks good to me.
Regards, Christian.
Signed-off-by: Tvrtko Ursulin tvrtko.ursulin@igalia.com References: 746ae46c1113 ("drm/sched: Mark scheduler work queues with WQ_MEM_RECLAIM") Fixes: a6149f039369 ("drm/sched: Convert drm scheduler to use a work queue rather than kthread") Cc: stable@vger.kernel.org Cc: Matthew Brost matthew.brost@intel.com Cc: Danilo Krummrich dakr@kernel.org Cc: Philipp Stanner pstanner@redhat.com Cc: Alex Deucher alexander.deucher@amd.com Cc: Christian König christian.koenig@amd.com
drivers/gpu/drm/amd/amdgpu/amdgpu.h | 2 ++ drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c | 25 +++++++++++++++++++++++++ drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c | 5 +++-- 3 files changed, 30 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h index 7645e498faa4..a6aad687537e 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h @@ -268,6 +268,8 @@ extern int amdgpu_agp; extern int amdgpu_wbrf; +extern struct workqueue_struct *amdgpu_reclaim_wq;
#define AMDGPU_VM_MAX_NUM_CTX 4096 #define AMDGPU_SG_THRESHOLD (256*1024*1024) #define AMDGPU_WAIT_IDLE_TIMEOUT_IN_MS 3000 diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c index 38686203bea6..f5b7172e8042 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c @@ -255,6 +255,8 @@ struct amdgpu_watchdog_timer amdgpu_watchdog_timer = { .period = 0x0, /* default to 0x0 (timeout disable) */ }; +struct workqueue_struct *amdgpu_reclaim_wq;
/** * DOC: vramlimit (int) * Restrict the total amount of VRAM in MiB for testing. The default is 0 (Use full VRAM). @@ -2971,6 +2973,21 @@ static struct pci_driver amdgpu_kms_pci_driver = { .dev_groups = amdgpu_sysfs_groups, }; +static int amdgpu_wq_init(void) +{ + amdgpu_reclaim_wq = + alloc_workqueue("amdgpu-reclaim", WQ_MEM_RECLAIM, 0); + if (!amdgpu_reclaim_wq) + return -ENOMEM;
+ return 0; +}
+static void amdgpu_wq_fini(void) +{ + destroy_workqueue(amdgpu_reclaim_wq); +}
static int __init amdgpu_init(void) { int r; @@ -2978,6 +2995,10 @@ static int __init amdgpu_init(void) if (drm_firmware_drivers_only()) return -EINVAL; + r = amdgpu_wq_init(); + if (r) + goto error_wq;
r = amdgpu_sync_init(); if (r) goto error_sync; @@ -3006,6 +3027,9 @@ static int __init amdgpu_init(void) amdgpu_sync_fini(); error_sync: + amdgpu_wq_fini();
+error_wq: return r; } @@ -3017,6 +3041,7 @@ static void __exit amdgpu_exit(void) amdgpu_acpi_release(); amdgpu_sync_fini(); amdgpu_fence_slab_fini(); + amdgpu_wq_fini(); mmu_notifier_synchronize(); amdgpu_xcp_drv_release(); } diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c index 2f3f09dfb1fd..f8fd71d9382f 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c @@ -790,8 +790,9 @@ void amdgpu_gfx_off_ctrl(struct amdgpu_device *adev, bool enable) AMD_IP_BLOCK_TYPE_GFX, true)) adev->gfx.gfx_off_state = true; } else {
- schedule_delayed_work(&adev->gfx.gfx_off_delay_work,
- delay); + queue_delayed_work(amdgpu_reclaim_wq,
- &adev->gfx.gfx_off_delay_work,
+ delay); } } } else {
On středa 13. listopadu 2024 14:48:38, středoevropský standardní čas Tvrtko Ursulin wrote:
From: Tvrtko Ursulin tvrtko.ursulin@igalia.com
As commit 746ae46c1113 ("drm/sched: Mark scheduler work queues with WQ_MEM_RECLAIM") points out, ever since a6149f039369 ("drm/sched: Convert drm scheduler to use a work queue rather than kthread"), any workqueue flushing done from the job submission path must only involve memory reclaim safe workqueues to be safe against reclaim deadlocks.
This is also pointed out by workqueue sanity checks:
[ ] workqueue: WQ_MEM_RECLAIM sdma0:drm_sched_run_job_work [gpu_sched] is flushing !WQ_MEM_RECLAIM events:amdgpu_device_delay_enable_gfx_off [amdgpu] ... [ ] Workqueue: sdma0 drm_sched_run_job_work [gpu_sched] ... [ ] Call Trace: [ ] <TASK> ... [ ] ? check_flush_dependency+0xf5/0x110 ... [ ] cancel_delayed_work_sync+0x6e/0x80 [ ] amdgpu_gfx_off_ctrl+0xab/0x140 [amdgpu] [ ] amdgpu_ring_alloc+0x40/0x50 [amdgpu] [ ] amdgpu_ib_schedule+0xf4/0x810 [amdgpu] [ ] ? drm_sched_run_job_work+0x22c/0x430 [gpu_sched] [ ] amdgpu_job_run+0xaa/0x1f0 [amdgpu] [ ] drm_sched_run_job_work+0x257/0x430 [gpu_sched] [ ] process_one_work+0x217/0x720 ... [ ] </TASK>
Fix this by creating a memory reclaim safe driver workqueue and make the submission path use it.
Signed-off-by: Tvrtko Ursulin tvrtko.ursulin@igalia.com References: 746ae46c1113 ("drm/sched: Mark scheduler work queues with WQ_MEM_RECLAIM") Fixes: a6149f039369 ("drm/sched: Convert drm scheduler to use a work queue rather than kthread") Cc: stable@vger.kernel.org Cc: Matthew Brost matthew.brost@intel.com Cc: Danilo Krummrich dakr@kernel.org Cc: Philipp Stanner pstanner@redhat.com Cc: Alex Deucher alexander.deucher@amd.com Cc: Christian König christian.koenig@amd.com
drivers/gpu/drm/amd/amdgpu/amdgpu.h | 2 ++ drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c | 25 +++++++++++++++++++++++++ drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c | 5 +++-- 3 files changed, 30 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h index 7645e498faa4..a6aad687537e 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h @@ -268,6 +268,8 @@ extern int amdgpu_agp; extern int amdgpu_wbrf; +extern struct workqueue_struct *amdgpu_reclaim_wq;
#define AMDGPU_VM_MAX_NUM_CTX 4096 #define AMDGPU_SG_THRESHOLD (256*1024*1024) #define AMDGPU_WAIT_IDLE_TIMEOUT_IN_MS 3000 diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c index 38686203bea6..f5b7172e8042 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c @@ -255,6 +255,8 @@ struct amdgpu_watchdog_timer amdgpu_watchdog_timer = { .period = 0x0, /* default to 0x0 (timeout disable) */ }; +struct workqueue_struct *amdgpu_reclaim_wq;
/**
- DOC: vramlimit (int)
- Restrict the total amount of VRAM in MiB for testing. The default is 0 (Use full VRAM).
@@ -2971,6 +2973,21 @@ static struct pci_driver amdgpu_kms_pci_driver = { .dev_groups = amdgpu_sysfs_groups, }; +static int amdgpu_wq_init(void) +{
- amdgpu_reclaim_wq =
alloc_workqueue("amdgpu-reclaim", WQ_MEM_RECLAIM, 0);- if (!amdgpu_reclaim_wq)
return -ENOMEM;- return 0;
+}
+static void amdgpu_wq_fini(void) +{
- destroy_workqueue(amdgpu_reclaim_wq);
+}
static int __init amdgpu_init(void) { int r; @@ -2978,6 +2995,10 @@ static int __init amdgpu_init(void) if (drm_firmware_drivers_only()) return -EINVAL;
- r = amdgpu_wq_init();
- if (r)
goto error_wq;- r = amdgpu_sync_init(); if (r) goto error_sync;
@@ -3006,6 +3027,9 @@ static int __init amdgpu_init(void) amdgpu_sync_fini(); error_sync:
- amdgpu_wq_fini();
+error_wq: return r; } @@ -3017,6 +3041,7 @@ static void __exit amdgpu_exit(void) amdgpu_acpi_release(); amdgpu_sync_fini(); amdgpu_fence_slab_fini();
- amdgpu_wq_fini(); mmu_notifier_synchronize(); amdgpu_xcp_drv_release();
} diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c index 2f3f09dfb1fd..f8fd71d9382f 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c @@ -790,8 +790,9 @@ void amdgpu_gfx_off_ctrl(struct amdgpu_device *adev, bool enable) AMD_IP_BLOCK_TYPE_GFX, true)) adev->gfx.gfx_off_state = true; } else {
schedule_delayed_work(&adev->gfx.gfx_off_delay_work,delay);
queue_delayed_work(amdgpu_reclaim_wq,&adev->gfx.gfx_off_delay_work,delay); }
I can confirm this fixed the warning for me.
Tested-by: Oleksandr Natalenko oleksandr@natalenko.name
What's the fate of this submission?
Thank you.
Am 03.12.24 um 15:24 schrieb Oleksandr Natalenko:
On středa 13. listopadu 2024 14:48:38, středoevropský standardní čas Tvrtko Ursulin wrote:
From: Tvrtko Ursulin tvrtko.ursulin@igalia.com
As commit 746ae46c1113 ("drm/sched: Mark scheduler work queues with WQ_MEM_RECLAIM") points out, ever since a6149f039369 ("drm/sched: Convert drm scheduler to use a work queue rather than kthread"), any workqueue flushing done from the job submission path must only involve memory reclaim safe workqueues to be safe against reclaim deadlocks.
This is also pointed out by workqueue sanity checks:
[ ] workqueue: WQ_MEM_RECLAIM sdma0:drm_sched_run_job_work [gpu_sched] is flushing !WQ_MEM_RECLAIM events:amdgpu_device_delay_enable_gfx_off [amdgpu] ... [ ] Workqueue: sdma0 drm_sched_run_job_work [gpu_sched] ... [ ] Call Trace: [ ] <TASK> ... [ ] ? check_flush_dependency+0xf5/0x110 ... [ ] cancel_delayed_work_sync+0x6e/0x80 [ ] amdgpu_gfx_off_ctrl+0xab/0x140 [amdgpu] [ ] amdgpu_ring_alloc+0x40/0x50 [amdgpu] [ ] amdgpu_ib_schedule+0xf4/0x810 [amdgpu] [ ] ? drm_sched_run_job_work+0x22c/0x430 [gpu_sched] [ ] amdgpu_job_run+0xaa/0x1f0 [amdgpu] [ ] drm_sched_run_job_work+0x257/0x430 [gpu_sched] [ ] process_one_work+0x217/0x720 ... [ ] </TASK>
Fix this by creating a memory reclaim safe driver workqueue and make the submission path use it.
Signed-off-by: Tvrtko Ursulin tvrtko.ursulin@igalia.com References: 746ae46c1113 ("drm/sched: Mark scheduler work queues with WQ_MEM_RECLAIM") Fixes: a6149f039369 ("drm/sched: Convert drm scheduler to use a work queue rather than kthread") Cc: stable@vger.kernel.org Cc: Matthew Brost matthew.brost@intel.com Cc: Danilo Krummrich dakr@kernel.org Cc: Philipp Stanner pstanner@redhat.com Cc: Alex Deucher alexander.deucher@amd.com Cc: Christian König christian.koenig@amd.com
drivers/gpu/drm/amd/amdgpu/amdgpu.h | 2 ++ drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c | 25 +++++++++++++++++++++++++ drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c | 5 +++-- 3 files changed, 30 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h index 7645e498faa4..a6aad687537e 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h @@ -268,6 +268,8 @@ extern int amdgpu_agp; extern int amdgpu_wbrf; +extern struct workqueue_struct *amdgpu_reclaim_wq;
- #define AMDGPU_VM_MAX_NUM_CTX 4096 #define AMDGPU_SG_THRESHOLD (256*1024*1024) #define AMDGPU_WAIT_IDLE_TIMEOUT_IN_MS 3000
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c index 38686203bea6..f5b7172e8042 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c @@ -255,6 +255,8 @@ struct amdgpu_watchdog_timer amdgpu_watchdog_timer = { .period = 0x0, /* default to 0x0 (timeout disable) */ }; +struct workqueue_struct *amdgpu_reclaim_wq;
- /**
- DOC: vramlimit (int)
- Restrict the total amount of VRAM in MiB for testing. The default is 0 (Use full VRAM).
@@ -2971,6 +2973,21 @@ static struct pci_driver amdgpu_kms_pci_driver = { .dev_groups = amdgpu_sysfs_groups, }; +static int amdgpu_wq_init(void) +{
- amdgpu_reclaim_wq =
alloc_workqueue("amdgpu-reclaim", WQ_MEM_RECLAIM, 0);- if (!amdgpu_reclaim_wq)
return -ENOMEM;- return 0;
+}
+static void amdgpu_wq_fini(void) +{
- destroy_workqueue(amdgpu_reclaim_wq);
+}
- static int __init amdgpu_init(void) { int r;
@@ -2978,6 +2995,10 @@ static int __init amdgpu_init(void) if (drm_firmware_drivers_only()) return -EINVAL;
- r = amdgpu_wq_init();
- if (r)
goto error_wq;- r = amdgpu_sync_init(); if (r) goto error_sync;
@@ -3006,6 +3027,9 @@ static int __init amdgpu_init(void) amdgpu_sync_fini(); error_sync:
- amdgpu_wq_fini();
+error_wq: return r; } @@ -3017,6 +3041,7 @@ static void __exit amdgpu_exit(void) amdgpu_acpi_release(); amdgpu_sync_fini(); amdgpu_fence_slab_fini();
- amdgpu_wq_fini(); mmu_notifier_synchronize(); amdgpu_xcp_drv_release(); }
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c index 2f3f09dfb1fd..f8fd71d9382f 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c @@ -790,8 +790,9 @@ void amdgpu_gfx_off_ctrl(struct amdgpu_device *adev, bool enable) AMD_IP_BLOCK_TYPE_GFX, true)) adev->gfx.gfx_off_state = true; } else {
schedule_delayed_work(&adev->gfx.gfx_off_delay_work,delay);
queue_delayed_work(amdgpu_reclaim_wq,&adev->gfx.gfx_off_delay_work,delay); }I can confirm this fixed the warning for me.
Tested-by: Oleksandr Natalenko oleksandr@natalenko.name
What's the fate of this submission?
It turned out that the warning is actually a false negative.
E.g. the warning shouldn't be printed in the first place.
Tvrtko pinged the relevant maintainer, but for far I haven't seen a reply.
Regards, Christian.
Thank you.
[+cc Krzysztof, who I think witnessed a possibly related Kernel crash in the wild]
P.
On Wed, 2024-11-13 at 13:48 +0000, Tvrtko Ursulin wrote:
From: Tvrtko Ursulin tvrtko.ursulin@igalia.com
As commit 746ae46c1113 ("drm/sched: Mark scheduler work queues with WQ_MEM_RECLAIM") points out, ever since a6149f039369 ("drm/sched: Convert drm scheduler to use a work queue rather than kthread"), any workqueue flushing done from the job submission path must only involve memory reclaim safe workqueues to be safe against reclaim deadlocks.
This is also pointed out by workqueue sanity checks:
[ ] workqueue: WQ_MEM_RECLAIM sdma0:drm_sched_run_job_work [gpu_sched] is flushing !WQ_MEM_RECLAIM events:amdgpu_device_delay_enable_gfx_off [amdgpu] ... [ ] Workqueue: sdma0 drm_sched_run_job_work [gpu_sched] ... [ ] Call Trace: [ ] <TASK> ... [ ] ? check_flush_dependency+0xf5/0x110 ... [ ] cancel_delayed_work_sync+0x6e/0x80 [ ] amdgpu_gfx_off_ctrl+0xab/0x140 [amdgpu] [ ] amdgpu_ring_alloc+0x40/0x50 [amdgpu] [ ] amdgpu_ib_schedule+0xf4/0x810 [amdgpu] [ ] ? drm_sched_run_job_work+0x22c/0x430 [gpu_sched] [ ] amdgpu_job_run+0xaa/0x1f0 [amdgpu] [ ] drm_sched_run_job_work+0x257/0x430 [gpu_sched] [ ] process_one_work+0x217/0x720 ... [ ] </TASK>
Fix this by creating a memory reclaim safe driver workqueue and make the submission path use it.
Signed-off-by: Tvrtko Ursulin tvrtko.ursulin@igalia.com References: 746ae46c1113 ("drm/sched: Mark scheduler work queues with WQ_MEM_RECLAIM") Fixes: a6149f039369 ("drm/sched: Convert drm scheduler to use a work queue rather than kthread") Cc: stable@vger.kernel.org Cc: Matthew Brost matthew.brost@intel.com Cc: Danilo Krummrich dakr@kernel.org Cc: Philipp Stanner pstanner@redhat.com Cc: Alex Deucher alexander.deucher@amd.com Cc: Christian König christian.koenig@amd.com
drivers/gpu/drm/amd/amdgpu/amdgpu.h | 2 ++ drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c | 25 +++++++++++++++++++++++++ drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c | 5 +++-- 3 files changed, 30 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h index 7645e498faa4..a6aad687537e 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h @@ -268,6 +268,8 @@ extern int amdgpu_agp; extern int amdgpu_wbrf; +extern struct workqueue_struct *amdgpu_reclaim_wq;
#define AMDGPU_VM_MAX_NUM_CTX 4096 #define AMDGPU_SG_THRESHOLD (256*1024*1024) #define AMDGPU_WAIT_IDLE_TIMEOUT_IN_MS 3000 diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c index 38686203bea6..f5b7172e8042 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c @@ -255,6 +255,8 @@ struct amdgpu_watchdog_timer amdgpu_watchdog_timer = { .period = 0x0, /* default to 0x0 (timeout disable) */ }; +struct workqueue_struct *amdgpu_reclaim_wq;
/** * DOC: vramlimit (int) * Restrict the total amount of VRAM in MiB for testing. The default is 0 (Use full VRAM). @@ -2971,6 +2973,21 @@ static struct pci_driver amdgpu_kms_pci_driver = { .dev_groups = amdgpu_sysfs_groups, }; +static int amdgpu_wq_init(void) +{
- amdgpu_reclaim_wq =
alloc_workqueue("amdgpu-reclaim", WQ_MEM_RECLAIM,0);
- if (!amdgpu_reclaim_wq)
return -ENOMEM;- return 0;
+}
+static void amdgpu_wq_fini(void) +{
- destroy_workqueue(amdgpu_reclaim_wq);
+}
static int __init amdgpu_init(void) { int r; @@ -2978,6 +2995,10 @@ static int __init amdgpu_init(void) if (drm_firmware_drivers_only()) return -EINVAL;
- r = amdgpu_wq_init();
- if (r)
goto error_wq;r = amdgpu_sync_init(); if (r) goto error_sync; @@ -3006,6 +3027,9 @@ static int __init amdgpu_init(void) amdgpu_sync_fini(); error_sync:
- amdgpu_wq_fini();
+error_wq: return r; } @@ -3017,6 +3041,7 @@ static void __exit amdgpu_exit(void) amdgpu_acpi_release(); amdgpu_sync_fini(); amdgpu_fence_slab_fini();
- amdgpu_wq_fini();
mmu_notifier_synchronize(); amdgpu_xcp_drv_release(); } diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c index 2f3f09dfb1fd..f8fd71d9382f 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c @@ -790,8 +790,9 @@ void amdgpu_gfx_off_ctrl(struct amdgpu_device *adev, bool enable) AMD_IP_BLOCK_TYPE_GF X, true)) adev->gfx.gfx_off_state = true; } else {
schedule_delayed_work(&adev-gfx.gfx_off_delay_work,
delay);
queue_delayed_work(amdgpu_reclaim_wq,
&adev-gfx.gfx_off_delay_work,
delay);} } } else {
linux-stable-mirror@lists.linaro.org
-
Christian König -
Matthew Brost -
Oleksandr Natalenko -
Philipp Stanner -
Tvrtko Ursulin -
Tvrtko Ursulin