[PATCH v2] drm/xe: Add timeout to preempt fences
Matthew Brost
matthew.brost at intel.com
Tue Jun 25 05:51:20 UTC 2024
To adhere to dma fencing rules that fences must signal within a
reasonable amount of time, add a 5 second timeout to preempt fences. If
this timeout occurs, kill the associated VM as this fatal to the VM.
v2:
- Add comment for smp_wmb (Checkpatch)
- Fix kernel doc typo (Inspection)
- Add comment for killed check (Niranjana)
Cc: Niranjana Vishwanathapura <niranjana.vishwanathapura at intel.com>
Signed-off-by: Matthew Brost <matthew.brost at intel.com>
Reviewed-by: Niranjana Vishwanathapura <niranjana.vishwanathapura at intel.com>
---
drivers/gpu/drm/xe/xe_exec_queue_types.h | 6 ++--
drivers/gpu/drm/xe/xe_execlist.c | 3 +-
drivers/gpu/drm/xe/xe_guc_submit.c | 41 ++++++++++++++++++++----
drivers/gpu/drm/xe/xe_preempt_fence.c | 14 +++++++-
drivers/gpu/drm/xe/xe_vm.c | 10 +++++-
drivers/gpu/drm/xe/xe_vm.h | 2 ++
6 files changed, 65 insertions(+), 11 deletions(-)
diff --git a/drivers/gpu/drm/xe/xe_exec_queue_types.h b/drivers/gpu/drm/xe/xe_exec_queue_types.h
index 201588ec33c3..1e51c978db7a 100644
--- a/drivers/gpu/drm/xe/xe_exec_queue_types.h
+++ b/drivers/gpu/drm/xe/xe_exec_queue_types.h
@@ -172,9 +172,11 @@ struct xe_exec_queue_ops {
int (*suspend)(struct xe_exec_queue *q);
/**
* @suspend_wait: Wait for an exec queue to suspend executing, should be
- * call after suspend.
+ * call after suspend. In dma-fencing path thus must return within a
+ * reasonable amount of time. A non-zero return shall indicate an error
+ * waiting for suspend.
*/
- void (*suspend_wait)(struct xe_exec_queue *q);
+ int (*suspend_wait)(struct xe_exec_queue *q);
/**
* @resume: Resume exec queue execution, exec queue must be in a suspended
* state and dma fence returned from most recent suspend call must be
diff --git a/drivers/gpu/drm/xe/xe_execlist.c b/drivers/gpu/drm/xe/xe_execlist.c
index db906117db6d..7502e3486eaf 100644
--- a/drivers/gpu/drm/xe/xe_execlist.c
+++ b/drivers/gpu/drm/xe/xe_execlist.c
@@ -422,10 +422,11 @@ static int execlist_exec_queue_suspend(struct xe_exec_queue *q)
return 0;
}
-static void execlist_exec_queue_suspend_wait(struct xe_exec_queue *q)
+static int execlist_exec_queue_suspend_wait(struct xe_exec_queue *q)
{
/* NIY */
+ return 0;
}
static void execlist_exec_queue_resume(struct xe_exec_queue *q)
diff --git a/drivers/gpu/drm/xe/xe_guc_submit.c b/drivers/gpu/drm/xe/xe_guc_submit.c
index 373447758a60..9df97ee94fca 100644
--- a/drivers/gpu/drm/xe/xe_guc_submit.c
+++ b/drivers/gpu/drm/xe/xe_guc_submit.c
@@ -1301,6 +1301,17 @@ static void __guc_exec_queue_process_msg_set_sched_props(struct xe_sched_msg *ms
kfree(msg);
}
+static void __suspend_fence_signal(struct xe_exec_queue *q)
+{
+ if (!q->guc->suspend_pending)
+ return;
+
+ q->guc->suspend_pending = false;
+ smp_wmb(); /* Ensure suspend_pending change is visible */
+
+ wake_up(&q->guc->suspend_wait);
+}
+
static void suspend_fence_signal(struct xe_exec_queue *q)
{
struct xe_guc *guc = exec_queue_to_guc(q);
@@ -1310,9 +1321,7 @@ static void suspend_fence_signal(struct xe_exec_queue *q)
guc_read_stopped(guc));
xe_assert(xe, q->guc->suspend_pending);
- q->guc->suspend_pending = false;
- smp_wmb();
- wake_up(&q->guc->suspend_wait);
+ __suspend_fence_signal(q);
}
static void __guc_exec_queue_process_msg_suspend(struct xe_sched_msg *msg)
@@ -1465,6 +1474,7 @@ static void guc_exec_queue_kill(struct xe_exec_queue *q)
{
trace_xe_exec_queue_kill(q);
set_exec_queue_killed(q);
+ __suspend_fence_signal(q);
xe_guc_exec_queue_trigger_cleanup(q);
}
@@ -1561,12 +1571,31 @@ static int guc_exec_queue_suspend(struct xe_exec_queue *q)
return 0;
}
-static void guc_exec_queue_suspend_wait(struct xe_exec_queue *q)
+static int guc_exec_queue_suspend_wait(struct xe_exec_queue *q)
{
struct xe_guc *guc = exec_queue_to_guc(q);
+ int ret;
+
+ /*
+ * Likely don't need to check exec_queue_killed() as we clear
+ * suspend_pending upon kill but to be paranoid but races in which
+ * suspend_pending is set after kill also check kill here.
+ */
+ ret = wait_event_timeout(q->guc->suspend_wait,
+ !q->guc->suspend_pending ||
+ exec_queue_killed(q) ||
+ guc_read_stopped(guc),
+ HZ * 5);
- wait_event(q->guc->suspend_wait, !q->guc->suspend_pending ||
- guc_read_stopped(guc));
+ if (!ret) {
+ xe_gt_warn(guc_to_gt(guc),
+ "Suspend fence, guc_id=%d, failed to respond",
+ q->guc->id);
+ /* XXX: Trigger GT reset? */
+ return -ETIME;
+ }
+
+ return 0;
}
static void guc_exec_queue_resume(struct xe_exec_queue *q)
diff --git a/drivers/gpu/drm/xe/xe_preempt_fence.c b/drivers/gpu/drm/xe/xe_preempt_fence.c
index e8b8ae5c6485..8356d9798206 100644
--- a/drivers/gpu/drm/xe/xe_preempt_fence.c
+++ b/drivers/gpu/drm/xe/xe_preempt_fence.c
@@ -16,11 +16,23 @@ static void preempt_fence_work_func(struct work_struct *w)
struct xe_preempt_fence *pfence =
container_of(w, typeof(*pfence), preempt_work);
struct xe_exec_queue *q = pfence->q;
+ int err = 0;
if (pfence->error)
dma_fence_set_error(&pfence->base, pfence->error);
+ else if (!q->ops->reset_status(q))
+ err = q->ops->suspend_wait(q);
else
- q->ops->suspend_wait(q);
+ dma_fence_set_error(&pfence->base, -ENOENT);
+
+ if (err) {
+ dma_fence_set_error(&pfence->base, err);
+
+ down_write(&q->vm->lock);
+ xe_vm_kill(q->vm, false);
+ up_write(&q->vm->lock);
+ }
+
dma_fence_signal(&pfence->base);
/*
diff --git a/drivers/gpu/drm/xe/xe_vm.c b/drivers/gpu/drm/xe/xe_vm.c
index 5b166fa03684..e7c15b7877b1 100644
--- a/drivers/gpu/drm/xe/xe_vm.c
+++ b/drivers/gpu/drm/xe/xe_vm.c
@@ -311,7 +311,15 @@ int __xe_vm_userptr_needs_repin(struct xe_vm *vm)
#define XE_VM_REBIND_RETRY_TIMEOUT_MS 1000
-static void xe_vm_kill(struct xe_vm *vm, bool unlocked)
+/**
+ * xe_vm_kill() - VM Kill
+ * @vm: The VM.
+ * @unlocked: Flag indicates the VM's dma-resv is not held
+ *
+ * Kill the VM by setting banned flag indicated VM is no longer available for
+ * use. If in preempt fence mode, also kill all exec queue attached to the VM.
+ */
+void xe_vm_kill(struct xe_vm *vm, bool unlocked)
{
struct xe_exec_queue *q;
diff --git a/drivers/gpu/drm/xe/xe_vm.h b/drivers/gpu/drm/xe/xe_vm.h
index b481608b12f1..c864dba35e1d 100644
--- a/drivers/gpu/drm/xe/xe_vm.h
+++ b/drivers/gpu/drm/xe/xe_vm.h
@@ -259,6 +259,8 @@ static inline struct dma_resv *xe_vm_resv(struct xe_vm *vm)
return drm_gpuvm_resv(&vm->gpuvm);
}
+void xe_vm_kill(struct xe_vm *vm, bool unlocked);
+
/**
* xe_vm_assert_held(vm) - Assert that the vm's reservation object is held.
* @vm: The vm
--
2.34.1
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