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drm/i915: Store the reset counter when constructing a request

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As the request is only valid during the same global reset epoch, we can
record the current reset_counter when constructing the request and reuse
it when waiting upon that request in future. This removes a very hairy
atomic check serialised by the struct_mutex at the time of waiting and
allows us to transfer those waits to a central dispatcher for all
waiters and all requests.

PS: With per-engine resets, we obviously cannot assume a global reset
epoch for the requests - a per-engine epoch makes the most sense. The
challenge then is how to handle checking in the waiter for when to break
the wait, as the fine-grained reset may also want to requeue the
request (i.e. the assumption that just because the epoch changes the
request is completed may be broken - or we just avoid breaking that
assumption with the fine-grained resets).

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1460565315-7748-7-git-send-email-chris@chris-wilson.co.uk
This commit is contained in:
Chris Wilson 2016-04-13 17:35:06 +01:00
parent d98c52cf4f
commit 299259a3a9
6 changed files with 16 additions and 51 deletions
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2
drivers/gpu/drm/i915/i915_drv.h
View file

@ -2250,6 +2250,7 @@ struct drm_i915_gem_request {
/** On Which ring this request was generated */
struct drm_i915_private *i915;
struct intel_engine_cs *engine;
unsigned reset_counter;
/** GEM sequence number associated with the previous request,
* when the HWS breadcrumb is equal to this the GPU is processing
@ -3160,7 +3161,6 @@ void __i915_add_request(struct drm_i915_gem_request *req,
#define i915_add_request_no_flush(req) \
__i915_add_request(req, NULL, false)
int __i915_wait_request(struct drm_i915_gem_request *req,
unsigned reset_counter,
bool interruptible,
s64 *timeout,
struct intel_rps_client *rps);

40
drivers/gpu/drm/i915/i915_gem.c
View file

@ -1213,7 +1213,6 @@ static int __i915_spin_request(struct drm_i915_gem_request *req, int state)
/**
* __i915_wait_request - wait until execution of request has finished
* @req: duh!
* @reset_counter: reset sequence associated with the given request
* @interruptible: do an interruptible wait (normally yes)
* @timeout: in - how long to wait (NULL forever); out - how much time remaining
*
@ -1228,7 +1227,6 @@ static int __i915_spin_request(struct drm_i915_gem_request *req, int state)
* errno with remaining time filled in timeout argument.
*/
int __i915_wait_request(struct drm_i915_gem_request *req,
unsigned reset_counter,
bool interruptible,
s64 *timeout,
struct intel_rps_client *rps)
@ -1290,7 +1288,7 @@ int __i915_wait_request(struct drm_i915_gem_request *req,
/* We need to check whether any gpu reset happened in between
* the caller grabbing the seqno and now ... */
if (reset_counter != i915_reset_counter(&dev_priv->gpu_error)) {
if (req->reset_counter != i915_reset_counter(&dev_priv->gpu_error)) {
/* ... but upgrade the -EAGAIN to an -EIO if the gpu
* is truely gone. */
ret = i915_gem_check_wedge(&dev_priv->gpu_error, interruptible);
@ -1460,13 +1458,7 @@ i915_wait_request(struct drm_i915_gem_request *req)
BUG_ON(!mutex_is_locked(&dev->struct_mutex));
ret = i915_gem_check_wedge(&dev_priv->gpu_error, interruptible);
if (ret)
return ret;
ret = __i915_wait_request(req,
i915_reset_counter(&dev_priv->gpu_error),
interruptible, NULL, NULL);
ret = __i915_wait_request(req, interruptible, NULL, NULL);
if (ret)
return ret;
@ -1541,7 +1533,6 @@ i915_gem_object_wait_rendering__nonblocking(struct drm_i915_gem_object *obj,
struct drm_device *dev = obj->base.dev;
struct drm_i915_private *dev_priv = dev->dev_private;
struct drm_i915_gem_request *requests[I915_NUM_ENGINES];
unsigned reset_counter;
int ret, i, n = 0;
BUG_ON(!mutex_is_locked(&dev->struct_mutex));
@ -1550,12 +1541,6 @@ i915_gem_object_wait_rendering__nonblocking(struct drm_i915_gem_object *obj,
if (!obj->active)
return 0;
ret = i915_gem_check_wedge(&dev_priv->gpu_error, true);
if (ret)
return ret;
reset_counter = i915_reset_counter(&dev_priv->gpu_error);
if (readonly) {
struct drm_i915_gem_request *req;
@ -1577,9 +1562,9 @@ i915_gem_object_wait_rendering__nonblocking(struct drm_i915_gem_object *obj,
}
mutex_unlock(&dev->struct_mutex);
ret = 0;
for (i = 0; ret == 0 && i < n; i++)
ret = __i915_wait_request(requests[i], reset_counter, true,
NULL, rps);
ret = __i915_wait_request(requests[i], true, NULL, rps);
mutex_lock(&dev->struct_mutex);
for (i = 0; i < n; i++) {
@ -2735,6 +2720,7 @@ __i915_gem_request_alloc(struct intel_engine_cs *engine,
struct drm_i915_gem_request **req_out)
{
struct drm_i915_private *dev_priv = to_i915(engine->dev);
unsigned reset_counter = i915_reset_counter(&dev_priv->gpu_error);
struct drm_i915_gem_request *req;
int ret;
@ -2743,6 +2729,11 @@ __i915_gem_request_alloc(struct intel_engine_cs *engine,
*req_out = NULL;
ret = i915_gem_check_wedge(&dev_priv->gpu_error,
dev_priv->mm.interruptible);
if (ret)
return ret;
req = kmem_cache_zalloc(dev_priv->requests, GFP_KERNEL);
if (req == NULL)
return -ENOMEM;
@ -2754,6 +2745,7 @@ __i915_gem_request_alloc(struct intel_engine_cs *engine,
kref_init(&req->ref);
req->i915 = dev_priv;
req->engine = engine;
req->reset_counter = reset_counter;
req->ctx = ctx;
i915_gem_context_reference(req->ctx);
@ -3132,11 +3124,9 @@ retire:
int
i915_gem_wait_ioctl(struct drm_device *dev, void *data, struct drm_file *file)
{
struct drm_i915_private *dev_priv = dev->dev_private;
struct drm_i915_gem_wait *args = data;
struct drm_i915_gem_object *obj;
struct drm_i915_gem_request *req[I915_NUM_ENGINES];
unsigned reset_counter;
int i, n = 0;
int ret;
@ -3170,7 +3160,6 @@ i915_gem_wait_ioctl(struct drm_device *dev, void *data, struct drm_file *file)
}
drm_gem_object_unreference(&obj->base);
reset_counter = i915_reset_counter(&dev_priv->gpu_error);
for (i = 0; i < I915_NUM_ENGINES; i++) {
if (obj->last_read_req[i] == NULL)
@ -3183,7 +3172,7 @@ i915_gem_wait_ioctl(struct drm_device *dev, void *data, struct drm_file *file)
for (i = 0; i < n; i++) {
if (ret == 0)
ret = __i915_wait_request(req[i], reset_counter, true,
ret = __i915_wait_request(req[i], true,
args->timeout_ns > 0 ? &args->timeout_ns : NULL,
to_rps_client(file));
i915_gem_request_unreference__unlocked(req[i]);
@ -3215,7 +3204,6 @@ __i915_gem_object_sync(struct drm_i915_gem_object *obj,
if (!i915_semaphore_is_enabled(obj->base.dev)) {
struct drm_i915_private *i915 = to_i915(obj->base.dev);
ret = __i915_wait_request(from_req,
i915_reset_counter(&i915->gpu_error),
i915->mm.interruptible,
NULL,
&i915->rps.semaphores);
@ -4171,7 +4159,6 @@ i915_gem_ring_throttle(struct drm_device *dev, struct drm_file *file)
struct drm_i915_file_private *file_priv = file->driver_priv;
unsigned long recent_enough = jiffies - DRM_I915_THROTTLE_JIFFIES;
struct drm_i915_gem_request *request, *target = NULL;
unsigned reset_counter;
int ret;
ret = i915_gem_wait_for_error(&dev_priv->gpu_error);
@ -4196,7 +4183,6 @@ i915_gem_ring_throttle(struct drm_device *dev, struct drm_file *file)
target = request;
}
reset_counter = i915_reset_counter(&dev_priv->gpu_error);
if (target)
i915_gem_request_reference(target);
spin_unlock(&file_priv->mm.lock);
@ -4204,7 +4190,7 @@ i915_gem_ring_throttle(struct drm_device *dev, struct drm_file *file)
if (target == NULL)
return 0;
ret = __i915_wait_request(target, reset_counter, true, NULL, NULL);
ret = __i915_wait_request(target, true, NULL, NULL);
if (ret == 0)
queue_delayed_work(dev_priv->wq, &dev_priv->mm.retire_work, 0);

5
drivers/gpu/drm/i915/i915_gem_userptr.c
View file

@ -65,7 +65,6 @@ static void wait_rendering(struct drm_i915_gem_object *obj)
{
struct drm_device *dev = obj->base.dev;
struct drm_i915_gem_request *requests[I915_NUM_ENGINES];
unsigned reset_counter;
int i, n;
if (!obj->active)
@ -82,12 +81,10 @@ static void wait_rendering(struct drm_i915_gem_object *obj)
requests[n++] = i915_gem_request_reference(req);
}
reset_counter = atomic_read(&to_i915(dev)->gpu_error.reset_counter);
mutex_unlock(&dev->struct_mutex);
for (i = 0; i < n; i++)
__i915_wait_request(requests[i], reset_counter, false,
NULL, NULL);
__i915_wait_request(requests[i], false, NULL, NULL);
mutex_lock(&dev->struct_mutex);

7
drivers/gpu/drm/i915/intel_display.c
View file

@ -11365,7 +11365,6 @@ static void intel_mmio_flip_work_func(struct work_struct *work)
if (mmio_flip->req) {
WARN_ON(__i915_wait_request(mmio_flip->req,
mmio_flip->crtc->reset_counter,
false, NULL,
&mmio_flip->i915->rps.mmioflips));
i915_gem_request_unreference__unlocked(mmio_flip->req);
@ -13426,9 +13425,6 @@ static int intel_atomic_prepare_commit(struct drm_device *dev,
ret = drm_atomic_helper_prepare_planes(dev, state);
if (!ret && !async && !i915_reset_in_progress_or_wedged(&dev_priv->gpu_error)) {
u32 reset_counter;
reset_counter = i915_reset_counter(&dev_priv->gpu_error);
mutex_unlock(&dev->struct_mutex);
for_each_plane_in_state(state, plane, plane_state, i) {
@ -13439,8 +13435,7 @@ static int intel_atomic_prepare_commit(struct drm_device *dev,
continue;
ret = __i915_wait_request(intel_plane_state->wait_req,
reset_counter, true,
NULL, NULL);
true, NULL, NULL);
/* Swallow -EIO errors to allow updates during hw lockup. */
if (ret == -EIO)

7
drivers/gpu/drm/i915/intel_lrc.c
View file

@ -890,16 +890,9 @@ static int logical_ring_prepare(struct drm_i915_gem_request *req, int bytes)
*/
int intel_logical_ring_begin(struct drm_i915_gem_request *req, int num_dwords)
{
struct drm_i915_private *dev_priv;
int ret;
WARN_ON(req == NULL);
dev_priv = req->i915;
ret = i915_gem_check_wedge(&dev_priv->gpu_error,
dev_priv->mm.interruptible);
if (ret)
return ret;
ret = logical_ring_prepare(req, num_dwords * sizeof(uint32_t));
if (ret)

6
drivers/gpu/drm/i915/intel_ringbuffer.c
View file

@ -2364,7 +2364,6 @@ int intel_engine_idle(struct intel_engine_cs *engine)
/* Make sure we do not trigger any retires */
return __i915_wait_request(req,
i915_reset_counter(&req->i915->gpu_error),
req->i915->mm.interruptible,
NULL, NULL);
}
@ -2495,11 +2494,6 @@ int intel_ring_begin(struct drm_i915_gem_request *req,
engine = req->engine;
dev_priv = req->i915;
ret = i915_gem_check_wedge(&dev_priv->gpu_error,
dev_priv->mm.interruptible);
if (ret)
return ret;
ret = __intel_ring_prepare(engine, num_dwords * sizeof(uint32_t));
if (ret)
return ret;