Extract of useful code from the timeline work. This provides a function to return a stub or dummy fence which is always signaled.
Signed-off-by: Christian König christian.koenig@amd.com --- drivers/dma-buf/dma-fence.c | 36 +++++++++++++++++++++++++++++++++++- include/linux/dma-fence.h | 1 + 2 files changed, 36 insertions(+), 1 deletion(-)
diff --git a/drivers/dma-buf/dma-fence.c b/drivers/dma-buf/dma-fence.c index 1551ca7df394..136ec04d683f 100644 --- a/drivers/dma-buf/dma-fence.c +++ b/drivers/dma-buf/dma-fence.c @@ -30,13 +30,16 @@ EXPORT_TRACEPOINT_SYMBOL(dma_fence_emit); EXPORT_TRACEPOINT_SYMBOL(dma_fence_enable_signal);
+static DEFINE_SPINLOCK(dma_fence_stub_lock); +static struct dma_fence dma_fence_stub; + /* * fence context counter: each execution context should have its own * fence context, this allows checking if fences belong to the same * context or not. One device can have multiple separate contexts, * and they're used if some engine can run independently of another. */ -static atomic64_t dma_fence_context_counter = ATOMIC64_INIT(0); +static atomic64_t dma_fence_context_counter = ATOMIC64_INIT(1);
/** * DOC: DMA fences overview @@ -68,6 +71,37 @@ static atomic64_t dma_fence_context_counter = ATOMIC64_INIT(0); * &dma_buf.resv pointer. */
+static const char *dma_fence_stub_get_name(struct dma_fence *fence) +{ + return "stub"; +} + +static const struct dma_fence_ops dma_fence_stub_ops = { + .get_driver_name = dma_fence_stub_get_name, + .get_timeline_name = dma_fence_stub_get_name, +}; + +/** + * dma_fence_get_stub - return a signaled fence + * + * Return a stub fence which is already signaled. + */ +struct dma_fence *dma_fence_get_stub(void) +{ + spin_lock(&dma_fence_stub_lock); + if (!dma_fence_stub.ops) { + dma_fence_init(&dma_fence_stub, + &dma_fence_stub_ops, + &dma_fence_stub_lock, + 0, 0); + dma_fence_signal_locked(&dma_fence_stub); + } + spin_unlock(&dma_fence_stub_lock); + + return dma_fence_get(&dma_fence_stub); +} +EXPORT_SYMBOL(dma_fence_get_stub); + /** * dma_fence_context_alloc - allocate an array of fence contexts * @num: amount of contexts to allocate diff --git a/include/linux/dma-fence.h b/include/linux/dma-fence.h index 02dba8cd033d..999e4b104410 100644 --- a/include/linux/dma-fence.h +++ b/include/linux/dma-fence.h @@ -541,6 +541,7 @@ static inline signed long dma_fence_wait(struct dma_fence *fence, bool intr) return ret < 0 ? ret : 0; }
+struct dma_fence *dma_fence_get_stub(void); u64 dma_fence_context_alloc(unsigned num);
#define DMA_FENCE_TRACE(f, fmt, args...) \
Extract of useful code from the timeline work. Let's use just a single stub fence instance instead of allocating a new one all the time.
Signed-off-by: Chunming Zhou david1.zhou@amd.com Signed-off-by: Christian König christian.koenig@amd.com --- drivers/gpu/drm/drm_syncobj.c | 58 +++++++++++-------------------------------- 1 file changed, 14 insertions(+), 44 deletions(-)
diff --git a/drivers/gpu/drm/drm_syncobj.c b/drivers/gpu/drm/drm_syncobj.c index e2c5b3ca4824..5c5ba1f14307 100644 --- a/drivers/gpu/drm/drm_syncobj.c +++ b/drivers/gpu/drm/drm_syncobj.c @@ -56,22 +56,6 @@ #include "drm_internal.h" #include <drm/drm_syncobj.h>
-struct drm_syncobj_stub_fence { - struct dma_fence base; - spinlock_t lock; -}; - -static const char *drm_syncobj_stub_fence_get_name(struct dma_fence *fence) -{ - return "syncobjstub"; -} - -static const struct dma_fence_ops drm_syncobj_stub_fence_ops = { - .get_driver_name = drm_syncobj_stub_fence_get_name, - .get_timeline_name = drm_syncobj_stub_fence_get_name, -}; - - /** * drm_syncobj_find - lookup and reference a sync object. * @file_private: drm file private pointer @@ -190,23 +174,18 @@ void drm_syncobj_replace_fence(struct drm_syncobj *syncobj, } EXPORT_SYMBOL(drm_syncobj_replace_fence);
-static int drm_syncobj_assign_null_handle(struct drm_syncobj *syncobj) +/** + * drm_syncobj_assign_null_handle - assign a stub fence to the sync object + * @syncobj: sync object to assign the fence on + * + * Assign a already signaled stub fence to the sync object. + */ +static void drm_syncobj_assign_null_handle(struct drm_syncobj *syncobj) { - struct drm_syncobj_stub_fence *fence; - fence = kzalloc(sizeof(*fence), GFP_KERNEL); - if (fence == NULL) - return -ENOMEM; + struct dma_fence *fence = dma_fence_get_stub();
- spin_lock_init(&fence->lock); - dma_fence_init(&fence->base, &drm_syncobj_stub_fence_ops, - &fence->lock, 0, 0); - dma_fence_signal(&fence->base); - - drm_syncobj_replace_fence(syncobj, 0, &fence->base); - - dma_fence_put(&fence->base); - - return 0; + drm_syncobj_replace_fence(syncobj, 0, fence); + dma_fence_put(fence); }
/** @@ -274,7 +253,6 @@ EXPORT_SYMBOL(drm_syncobj_free); int drm_syncobj_create(struct drm_syncobj **out_syncobj, uint32_t flags, struct dma_fence *fence) { - int ret; struct drm_syncobj *syncobj;
syncobj = kzalloc(sizeof(struct drm_syncobj), GFP_KERNEL); @@ -285,13 +263,8 @@ int drm_syncobj_create(struct drm_syncobj **out_syncobj, uint32_t flags, INIT_LIST_HEAD(&syncobj->cb_list); spin_lock_init(&syncobj->lock);
- if (flags & DRM_SYNCOBJ_CREATE_SIGNALED) { - ret = drm_syncobj_assign_null_handle(syncobj); - if (ret < 0) { - drm_syncobj_put(syncobj); - return ret; - } - } + if (flags & DRM_SYNCOBJ_CREATE_SIGNALED) + drm_syncobj_assign_null_handle(syncobj);
if (fence) drm_syncobj_replace_fence(syncobj, 0, fence); @@ -982,11 +955,8 @@ drm_syncobj_signal_ioctl(struct drm_device *dev, void *data, if (ret < 0) return ret;
- for (i = 0; i < args->count_handles; i++) { - ret = drm_syncobj_assign_null_handle(syncobjs[i]); - if (ret < 0) - break; - } + for (i = 0; i < args->count_handles; i++) + drm_syncobj_assign_null_handle(syncobjs[i]);
drm_syncobj_array_free(syncobjs, args->count_handles);
Quoting Christian König (2018-12-03 13:07:58)
Extract of useful code from the timeline work. Let's use just a single stub fence instance instead of allocating a new one all the time.
Signed-off-by: Chunming Zhou david1.zhou@amd.com Signed-off-by: Christian König christian.koenig@amd.com
Reviewed-by: Chris Wilson chris@chris-wilson.co.uk -Chris
When the fence is already signaled it is perfectly normal to get a NULL fence here. But since we can't export that we need to use a stub fence.
Signed-off-by: Christian König christian.koenig@amd.com --- drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c index 024dfbd87f11..fe6bec2075c4 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c @@ -1421,6 +1421,9 @@ int amdgpu_cs_fence_to_handle_ioctl(struct drm_device *dev, void *data, if (IS_ERR(fence)) return PTR_ERR(fence);
+ if (!fence) + fence = dma_fence_get_stub(); + switch (info->in.what) { case AMDGPU_FENCE_TO_HANDLE_GET_SYNCOBJ: r = drm_syncobj_create(&syncobj, 0, fence);
The series is Reviewed-by: Chunming Zhou david1.zhou@amd.com
for patch#2, please remove my Signed-off-by, it's new when using stub from dma-fence.
-David
在 2018/12/3 21:07, Christian König 写道:
Extract of useful code from the timeline work. This provides a function to return a stub or dummy fence which is always signaled.
Signed-off-by: Christian König christian.koenig@amd.com
drivers/dma-buf/dma-fence.c | 36 +++++++++++++++++++++++++++++++++++- include/linux/dma-fence.h | 1 + 2 files changed, 36 insertions(+), 1 deletion(-)
diff --git a/drivers/dma-buf/dma-fence.c b/drivers/dma-buf/dma-fence.c index 1551ca7df394..136ec04d683f 100644 --- a/drivers/dma-buf/dma-fence.c +++ b/drivers/dma-buf/dma-fence.c @@ -30,13 +30,16 @@ EXPORT_TRACEPOINT_SYMBOL(dma_fence_emit); EXPORT_TRACEPOINT_SYMBOL(dma_fence_enable_signal);
+static DEFINE_SPINLOCK(dma_fence_stub_lock); +static struct dma_fence dma_fence_stub;
- /*
*/
- fence context counter: each execution context should have its own
- fence context, this allows checking if fences belong to the same
- context or not. One device can have multiple separate contexts,
- and they're used if some engine can run independently of another.
-static atomic64_t dma_fence_context_counter = ATOMIC64_INIT(0); +static atomic64_t dma_fence_context_counter = ATOMIC64_INIT(1);
/**
- DOC: DMA fences overview
@@ -68,6 +71,37 @@ static atomic64_t dma_fence_context_counter = ATOMIC64_INIT(0);
- &dma_buf.resv pointer.
*/
+static const char *dma_fence_stub_get_name(struct dma_fence *fence) +{
return "stub";+}
+static const struct dma_fence_ops dma_fence_stub_ops = {
- .get_driver_name = dma_fence_stub_get_name,
- .get_timeline_name = dma_fence_stub_get_name,
+};
+/**
- dma_fence_get_stub - return a signaled fence
- Return a stub fence which is already signaled.
- */
+struct dma_fence *dma_fence_get_stub(void) +{
- spin_lock(&dma_fence_stub_lock);
- if (!dma_fence_stub.ops) {
dma_fence_init(&dma_fence_stub,&dma_fence_stub_ops,&dma_fence_stub_lock,0, 0);dma_fence_signal_locked(&dma_fence_stub);- }
- spin_unlock(&dma_fence_stub_lock);
- return dma_fence_get(&dma_fence_stub);
+} +EXPORT_SYMBOL(dma_fence_get_stub);
- /**
- dma_fence_context_alloc - allocate an array of fence contexts
- @num: amount of contexts to allocate
diff --git a/include/linux/dma-fence.h b/include/linux/dma-fence.h index 02dba8cd033d..999e4b104410 100644 --- a/include/linux/dma-fence.h +++ b/include/linux/dma-fence.h @@ -541,6 +541,7 @@ static inline signed long dma_fence_wait(struct dma_fence *fence, bool intr) return ret < 0 ? ret : 0; }
+struct dma_fence *dma_fence_get_stub(void); u64 dma_fence_context_alloc(unsigned num);
#define DMA_FENCE_TRACE(f, fmt, args...) \
Am 03.12.18 um 14:33 schrieb Chunming Zhou:
The series is Reviewed-by: Chunming Zhou david1.zhou@amd.com
for patch#2, please remove my Signed-off-by, it's new when using stub from dma-fence.
Yeah, ok. There is indeed nothing left from your original code.
Alex, Daniel, Chris any objections that I push the first two patches in this series to drm-misc-next?
Shouldn't be any functional change, Christian.
-David
在 2018/12/3 21:07, Christian König 写道:
Extract of useful code from the timeline work. This provides a function to return a stub or dummy fence which is always signaled.
Signed-off-by: Christian König christian.koenig@amd.com
drivers/dma-buf/dma-fence.c | 36 +++++++++++++++++++++++++++++++++++- include/linux/dma-fence.h | 1 + 2 files changed, 36 insertions(+), 1 deletion(-)
diff --git a/drivers/dma-buf/dma-fence.c b/drivers/dma-buf/dma-fence.c index 1551ca7df394..136ec04d683f 100644 --- a/drivers/dma-buf/dma-fence.c +++ b/drivers/dma-buf/dma-fence.c @@ -30,13 +30,16 @@ EXPORT_TRACEPOINT_SYMBOL(dma_fence_emit); EXPORT_TRACEPOINT_SYMBOL(dma_fence_enable_signal);
+static DEFINE_SPINLOCK(dma_fence_stub_lock); +static struct dma_fence dma_fence_stub;
- /*
*/
- fence context counter: each execution context should have its own
- fence context, this allows checking if fences belong to the same
- context or not. One device can have multiple separate contexts,
- and they're used if some engine can run independently of another.
-static atomic64_t dma_fence_context_counter = ATOMIC64_INIT(0); +static atomic64_t dma_fence_context_counter = ATOMIC64_INIT(1);
/** * DOC: DMA fences overview @@ -68,6 +71,37 @@ static atomic64_t dma_fence_context_counter = ATOMIC64_INIT(0); * &dma_buf.resv pointer. */
+static const char *dma_fence_stub_get_name(struct dma_fence *fence) +{
return "stub";+}
+static const struct dma_fence_ops dma_fence_stub_ops = {
- .get_driver_name = dma_fence_stub_get_name,
- .get_timeline_name = dma_fence_stub_get_name,
+};
+/**
- dma_fence_get_stub - return a signaled fence
- Return a stub fence which is already signaled.
- */
+struct dma_fence *dma_fence_get_stub(void) +{
- spin_lock(&dma_fence_stub_lock);
- if (!dma_fence_stub.ops) {
dma_fence_init(&dma_fence_stub,&dma_fence_stub_ops,&dma_fence_stub_lock,0, 0);dma_fence_signal_locked(&dma_fence_stub);- }
- spin_unlock(&dma_fence_stub_lock);
- return dma_fence_get(&dma_fence_stub);
+} +EXPORT_SYMBOL(dma_fence_get_stub);
- /**
- dma_fence_context_alloc - allocate an array of fence contexts
- @num: amount of contexts to allocate
diff --git a/include/linux/dma-fence.h b/include/linux/dma-fence.h index 02dba8cd033d..999e4b104410 100644 --- a/include/linux/dma-fence.h +++ b/include/linux/dma-fence.h @@ -541,6 +541,7 @@ static inline signed long dma_fence_wait(struct dma_fence *fence, bool intr) return ret < 0 ? ret : 0; }
+struct dma_fence *dma_fence_get_stub(void); u64 dma_fence_context_alloc(unsigned num);
#define DMA_FENCE_TRACE(f, fmt, args...) \
dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel
On Mon, Dec 3, 2018 at 8:40 AM Christian König ckoenig.leichtzumerken@gmail.com wrote:
Am 03.12.18 um 14:33 schrieb Chunming Zhou:
The series is Reviewed-by: Chunming Zhou david1.zhou@amd.com
for patch#2, please remove my Signed-off-by, it's new when using stub from dma-fence.
Yeah, ok. There is indeed nothing left from your original code.
Alex, Daniel, Chris any objections that I push the first two patches in this series to drm-misc-next?
No objections from me. Does Intel want to run it through their CI?
Alex
Shouldn't be any functional change, Christian.
-David
在 2018/12/3 21:07, Christian König 写道:
Extract of useful code from the timeline work. This provides a function to return a stub or dummy fence which is always signaled.
Signed-off-by: Christian König christian.koenig@amd.com
drivers/dma-buf/dma-fence.c | 36 +++++++++++++++++++++++++++++++++++- include/linux/dma-fence.h | 1 + 2 files changed, 36 insertions(+), 1 deletion(-)
diff --git a/drivers/dma-buf/dma-fence.c b/drivers/dma-buf/dma-fence.c index 1551ca7df394..136ec04d683f 100644 --- a/drivers/dma-buf/dma-fence.c +++ b/drivers/dma-buf/dma-fence.c @@ -30,13 +30,16 @@ EXPORT_TRACEPOINT_SYMBOL(dma_fence_emit); EXPORT_TRACEPOINT_SYMBOL(dma_fence_enable_signal);
+static DEFINE_SPINLOCK(dma_fence_stub_lock); +static struct dma_fence dma_fence_stub;
- /*
*/
- fence context counter: each execution context should have its own
- fence context, this allows checking if fences belong to the same
- context or not. One device can have multiple separate contexts,
- and they're used if some engine can run independently of another.
-static atomic64_t dma_fence_context_counter = ATOMIC64_INIT(0); +static atomic64_t dma_fence_context_counter = ATOMIC64_INIT(1);
/** * DOC: DMA fences overview @@ -68,6 +71,37 @@ static atomic64_t dma_fence_context_counter = ATOMIC64_INIT(0); * &dma_buf.resv pointer. */
+static const char *dma_fence_stub_get_name(struct dma_fence *fence) +{
return "stub";+}
+static const struct dma_fence_ops dma_fence_stub_ops = {
- .get_driver_name = dma_fence_stub_get_name,
- .get_timeline_name = dma_fence_stub_get_name,
+};
+/**
- dma_fence_get_stub - return a signaled fence
- Return a stub fence which is already signaled.
- */
+struct dma_fence *dma_fence_get_stub(void) +{
- spin_lock(&dma_fence_stub_lock);
- if (!dma_fence_stub.ops) {
dma_fence_init(&dma_fence_stub,&dma_fence_stub_ops,&dma_fence_stub_lock,0, 0);dma_fence_signal_locked(&dma_fence_stub);- }
- spin_unlock(&dma_fence_stub_lock);
- return dma_fence_get(&dma_fence_stub);
+} +EXPORT_SYMBOL(dma_fence_get_stub);
- /**
- dma_fence_context_alloc - allocate an array of fence contexts
- @num: amount of contexts to allocate
diff --git a/include/linux/dma-fence.h b/include/linux/dma-fence.h index 02dba8cd033d..999e4b104410 100644 --- a/include/linux/dma-fence.h +++ b/include/linux/dma-fence.h @@ -541,6 +541,7 @@ static inline signed long dma_fence_wait(struct dma_fence *fence, bool intr) return ret < 0 ? ret : 0; }
+struct dma_fence *dma_fence_get_stub(void); u64 dma_fence_context_alloc(unsigned num);
#define DMA_FENCE_TRACE(f, fmt, args...) \
dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel
dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel
Quoting Alex Deucher (2018-12-03 15:53:21)
On Mon, Dec 3, 2018 at 8:40 AM Christian König ckoenig.leichtzumerken@gmail.com wrote:
Am 03.12.18 um 14:33 schrieb Chunming Zhou:
The series is Reviewed-by: Chunming Zhou david1.zhou@amd.com
for patch#2, please remove my Signed-off-by, it's new when using stub from dma-fence.
Yeah, ok. There is indeed nothing left from your original code.
Alex, Daniel, Chris any objections that I push the first two patches in this series to drm-misc-next?
No objections from me. Does Intel want to run it through their CI?
Gut feeling says we have no test coverage for SYNCOBJ_CREATE_SIGNALED. -Chris
Quoting Christian König (2018-12-03 13:07:57)
Extract of useful code from the timeline work. This provides a function to return a stub or dummy fence which is always signaled.
Signed-off-by: Christian König christian.koenig@amd.com
Reviewed-by: Chris Wilson chris@chris-wilson.co.uk -Chris
Christian König ckoenig.leichtzumerken@gmail.com writes:
Extract of useful code from the timeline work. This provides a function to return a stub or dummy fence which is always signaled.
Signed-off-by: Christian König christian.koenig@amd.com
drivers/dma-buf/dma-fence.c | 36 +++++++++++++++++++++++++++++++++++- include/linux/dma-fence.h | 1 + 2 files changed, 36 insertions(+), 1 deletion(-)
diff --git a/drivers/dma-buf/dma-fence.c b/drivers/dma-buf/dma-fence.c index 1551ca7df394..136ec04d683f 100644 --- a/drivers/dma-buf/dma-fence.c +++ b/drivers/dma-buf/dma-fence.c
/*
- fence context counter: each execution context should have its own
- fence context, this allows checking if fences belong to the same
- context or not. One device can have multiple separate contexts,
- and they're used if some engine can run independently of another.
*/ -static atomic64_t dma_fence_context_counter = ATOMIC64_INIT(0); +static atomic64_t dma_fence_context_counter = ATOMIC64_INIT(1);
What's this change for? I don't see a context allocation in patch #2 where the stub fence is being moved from, so this seems out of place.
Am 03.12.18 um 17:08 schrieb Eric Anholt:
Christian König ckoenig.leichtzumerken@gmail.com writes:
Extract of useful code from the timeline work. This provides a function to return a stub or dummy fence which is always signaled.
Signed-off-by: Christian König christian.koenig@amd.com
drivers/dma-buf/dma-fence.c | 36 +++++++++++++++++++++++++++++++++++- include/linux/dma-fence.h | 1 + 2 files changed, 36 insertions(+), 1 deletion(-)
diff --git a/drivers/dma-buf/dma-fence.c b/drivers/dma-buf/dma-fence.c index 1551ca7df394..136ec04d683f 100644 --- a/drivers/dma-buf/dma-fence.c +++ b/drivers/dma-buf/dma-fence.c /*
- fence context counter: each execution context should have its own
- fence context, this allows checking if fences belong to the same
- context or not. One device can have multiple separate contexts,
- and they're used if some engine can run independently of another.
*/ -static atomic64_t dma_fence_context_counter = ATOMIC64_INIT(0); +static atomic64_t dma_fence_context_counter = ATOMIC64_INIT(1);
What's this change for? I don't see a context allocation in patch #2 where the stub fence is being moved from, so this seems out of place.
The stub fence is using context 0 and seqno 0, but since it is always signaled this actually shouldn't matter.
So this is just to be on the extra clean side I made sure that nobody else is using context 0.
Alternatively we could also just allocate one when we initialize it for the first time.
Christian.
Christian König ckoenig.leichtzumerken@gmail.com writes:
Am 03.12.18 um 17:08 schrieb Eric Anholt:
Christian König ckoenig.leichtzumerken@gmail.com writes:
Extract of useful code from the timeline work. This provides a function to return a stub or dummy fence which is always signaled.
Signed-off-by: Christian König christian.koenig@amd.com
drivers/dma-buf/dma-fence.c | 36 +++++++++++++++++++++++++++++++++++- include/linux/dma-fence.h | 1 + 2 files changed, 36 insertions(+), 1 deletion(-)
diff --git a/drivers/dma-buf/dma-fence.c b/drivers/dma-buf/dma-fence.c index 1551ca7df394..136ec04d683f 100644 --- a/drivers/dma-buf/dma-fence.c +++ b/drivers/dma-buf/dma-fence.c /*
- fence context counter: each execution context should have its own
- fence context, this allows checking if fences belong to the same
- context or not. One device can have multiple separate contexts,
- and they're used if some engine can run independently of another.
*/ -static atomic64_t dma_fence_context_counter = ATOMIC64_INIT(0); +static atomic64_t dma_fence_context_counter = ATOMIC64_INIT(1);
What's this change for? I don't see a context allocation in patch #2 where the stub fence is being moved from, so this seems out of place.
The stub fence is using context 0 and seqno 0, but since it is always signaled this actually shouldn't matter.
So this is just to be on the extra clean side I made sure that nobody else is using context 0.
Alternatively we could also just allocate one when we initialize it for the first time.
I like the allocate at init idea.
Quoting Christian König (2018-12-03 16:12:14)
Am 03.12.18 um 17:08 schrieb Eric Anholt:
Christian König ckoenig.leichtzumerken@gmail.com writes:
Extract of useful code from the timeline work. This provides a function to return a stub or dummy fence which is always signaled.
Signed-off-by: Christian König christian.koenig@amd.com
drivers/dma-buf/dma-fence.c | 36 +++++++++++++++++++++++++++++++++++- include/linux/dma-fence.h | 1 + 2 files changed, 36 insertions(+), 1 deletion(-)
diff --git a/drivers/dma-buf/dma-fence.c b/drivers/dma-buf/dma-fence.c index 1551ca7df394..136ec04d683f 100644 --- a/drivers/dma-buf/dma-fence.c +++ b/drivers/dma-buf/dma-fence.c /*
- fence context counter: each execution context should have its own
- fence context, this allows checking if fences belong to the same
- context or not. One device can have multiple separate contexts,
- and they're used if some engine can run independently of another.
*/ -static atomic64_t dma_fence_context_counter = ATOMIC64_INIT(0); +static atomic64_t dma_fence_context_counter = ATOMIC64_INIT(1);
What's this change for? I don't see a context allocation in patch #2 where the stub fence is being moved from, so this seems out of place.
The stub fence is using context 0 and seqno 0, but since it is always signaled this actually shouldn't matter.
So this is just to be on the extra clean side I made sure that nobody else is using context 0.
I would like to be able to reserve 0 for NO_CONTEXT! The stub being but one example. -Chris
Am 03.12.18 um 18:06 schrieb Chris Wilson:
Quoting Christian König (2018-12-03 16:12:14)
Am 03.12.18 um 17:08 schrieb Eric Anholt:
Christian König ckoenig.leichtzumerken@gmail.com writes:
Extract of useful code from the timeline work. This provides a function to return a stub or dummy fence which is always signaled.
Signed-off-by: Christian König christian.koenig@amd.com
drivers/dma-buf/dma-fence.c | 36 +++++++++++++++++++++++++++++++++++- include/linux/dma-fence.h | 1 + 2 files changed, 36 insertions(+), 1 deletion(-)
diff --git a/drivers/dma-buf/dma-fence.c b/drivers/dma-buf/dma-fence.c index 1551ca7df394..136ec04d683f 100644 --- a/drivers/dma-buf/dma-fence.c +++ b/drivers/dma-buf/dma-fence.c /* * fence context counter: each execution context should have its own * fence context, this allows checking if fences belong to the same * context or not. One device can have multiple separate contexts, * and they're used if some engine can run independently of another. */ -static atomic64_t dma_fence_context_counter = ATOMIC64_INIT(0); +static atomic64_t dma_fence_context_counter = ATOMIC64_INIT(1);
What's this change for? I don't see a context allocation in patch #2 where the stub fence is being moved from, so this seems out of place.
The stub fence is using context 0 and seqno 0, but since it is always signaled this actually shouldn't matter.
So this is just to be on the extra clean side I made sure that nobody else is using context 0.
I would like to be able to reserve 0 for NO_CONTEXT! The stub being but one example.
I'm slightly leaning into this direction as well and additional to that I've already pushed the patches to drm-misc-next.
The only thing we should avoid is to over use 0 as NO_context, e.g. with complicated sequence numbers or similar.
Christian.
-Chris _______________________________________________ amd-gfx mailing list amd-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/amd-gfx
Quoting Eric Anholt (2018-12-03 16:08:40)
Christian König ckoenig.leichtzumerken@gmail.com writes:
Extract of useful code from the timeline work. This provides a function to return a stub or dummy fence which is always signaled.
Signed-off-by: Christian König christian.koenig@amd.com
drivers/dma-buf/dma-fence.c | 36 +++++++++++++++++++++++++++++++++++- include/linux/dma-fence.h | 1 + 2 files changed, 36 insertions(+), 1 deletion(-)
diff --git a/drivers/dma-buf/dma-fence.c b/drivers/dma-buf/dma-fence.c index 1551ca7df394..136ec04d683f 100644 --- a/drivers/dma-buf/dma-fence.c +++ b/drivers/dma-buf/dma-fence.c
/*
- fence context counter: each execution context should have its own
- fence context, this allows checking if fences belong to the same
- context or not. One device can have multiple separate contexts,
- and they're used if some engine can run independently of another.
*/ -static atomic64_t dma_fence_context_counter = ATOMIC64_INIT(0); +static atomic64_t dma_fence_context_counter = ATOMIC64_INIT(1);
What's this change for? I don't see a context allocation in patch #2 where the stub fence is being moved from, so this seems out of place.
I looked as it as being recognition that the stub-fence already exists on context 0, and so we should reserve that context for private use. -Chris
dri-devel@lists.freedesktop.org
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Alex Deucher -
Chris Wilson -
Christian König -
Chunming Zhou -
Eric Anholt