radv: Avoid deadlock on bo_list.

With the kernel timeline sysncobj changes, the kernel submits do
not necessarily happen in global vkQueueSubmit order. Which should
be fine, we added the appropriate waits for that. (See
DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT in the winsys)

However, all kernel submissions take a lock on the bo_list mutex,
and since we do the wait in the winsys, we wait while having the
bo_list mutex held. This means that as soon as a wait and a signal
submission are out of order we have a deadlock on the bo_list mutex
and the wait.

Solution is to use a shared reader lock during the kernel submission,
as we only need read access for the submission.

Fixes: 6bc5ce7a91d "radv: Add timeline syncobj for timeline semaphores."
Closes: https://gitlab.freedesktop.org/mesa/mesa/-/issues/3446
Reviewed-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6478>

diff --git a/src/amd/vulkan/radv_device.c b/src/amd/vulkan/radv_device.c
index 90167a9d60387c725879b546184790a272347bbf..ff62890217b60bceb4a54dd738b543a35353f3e3 100644 (file)
--- a/src/amd/vulkan/radv_device.c
+++ b/src/amd/vulkan/radv_device.c
@@ -2372,7 +2372,7 @@ radv_queue_finish(struct radv_queue *queue)
 static void
 radv_bo_list_init(struct radv_bo_list *bo_list)
 {
-       pthread_mutex_init(&bo_list->mutex, NULL);
+       pthread_rwlock_init(&bo_list->rwlock, NULL);
        bo_list->list.count = bo_list->capacity = 0;
        bo_list->list.bos = NULL;
 }
@@ -2381,7 +2381,7 @@ static void
 radv_bo_list_finish(struct radv_bo_list *bo_list)
 {
        free(bo_list->list.bos);
-       pthread_mutex_destroy(&bo_list->mutex);
+       pthread_rwlock_destroy(&bo_list->rwlock);
 }
 
 VkResult radv_bo_list_add(struct radv_device *device,
@@ -2395,13 +2395,13 @@ VkResult radv_bo_list_add(struct radv_device *device,
        if (unlikely(!device->use_global_bo_list))
                return VK_SUCCESS;
 
-       pthread_mutex_lock(&bo_list->mutex);
+       pthread_rwlock_wrlock(&bo_list->rwlock);
        if (bo_list->list.count == bo_list->capacity) {
                unsigned capacity = MAX2(4, bo_list->capacity * 2);
                void *data = realloc(bo_list->list.bos, capacity * sizeof(struct radeon_winsys_bo*));
 
                if (!data) {
-                       pthread_mutex_unlock(&bo_list->mutex);
+                       pthread_rwlock_unlock(&bo_list->rwlock);
                        return VK_ERROR_OUT_OF_HOST_MEMORY;
                }
 
@@ -2410,7 +2410,7 @@ VkResult radv_bo_list_add(struct radv_device *device,
        }
 
        bo_list->list.bos[bo_list->list.count++] = bo;
-       pthread_mutex_unlock(&bo_list->mutex);
+       pthread_rwlock_unlock(&bo_list->rwlock);
        return VK_SUCCESS;
 }
 
@@ -2425,7 +2425,7 @@ void radv_bo_list_remove(struct radv_device *device,
        if (unlikely(!device->use_global_bo_list))
                return;
 
-       pthread_mutex_lock(&bo_list->mutex);
+       pthread_rwlock_wrlock(&bo_list->rwlock);
        /* Loop the list backwards so we find the most recently added
         * memory first. */
        for(unsigned i = bo_list->list.count; i-- > 0;) {
@@ -2435,7 +2435,7 @@ void radv_bo_list_remove(struct radv_device *device,
                        break;
                }
        }
-       pthread_mutex_unlock(&bo_list->mutex);
+       pthread_rwlock_unlock(&bo_list->rwlock);
 }
 
 static void
@@ -4549,7 +4549,7 @@ radv_queue_submit_deferred(struct radv_deferred_queue_submission *submission,
                        sem_info.cs_emit_signal = j + advance == submission->cmd_buffer_count;
 
                        if (unlikely(queue->device->use_global_bo_list)) {
-                               pthread_mutex_lock(&queue->device->bo_list.mutex);
+                               pthread_rwlock_rdlock(&queue->device->bo_list.rwlock);
                                bo_list = &queue->device->bo_list.list;
                        }
 
@@ -4559,7 +4559,7 @@ radv_queue_submit_deferred(struct radv_deferred_queue_submission *submission,
                                                              can_patch, base_fence);
 
                        if (unlikely(queue->device->use_global_bo_list))
-                               pthread_mutex_unlock(&queue->device->bo_list.mutex);
+                               pthread_rwlock_unlock(&queue->device->bo_list.rwlock);
 
                        if (result != VK_SUCCESS)
                                goto fail;

diff --git a/src/amd/vulkan/radv_private.h b/src/amd/vulkan/radv_private.h
index bb58fa700feade9ccac1c6352f46e807fa31d1ec..90012cdf45ab1d68d818dea30b81e8cdd9fb9e3c 100644 (file)
--- a/src/amd/vulkan/radv_private.h
+++ b/src/amd/vulkan/radv_private.h
@@ -741,7 +741,7 @@ struct radv_queue {
 struct radv_bo_list {
        struct radv_winsys_bo_list list;
        unsigned capacity;
-       pthread_mutex_t mutex;
+       pthread_rwlock_t rwlock;
 };
 
 VkResult radv_bo_list_add(struct radv_device *device,