drm/radeon: let sa manager block for fences to wait for v2

Otherwise we can encounter out of memory situations under extreme load.

v2: add documentation for the new function

Signed-off-by: Christian König <deathsimple@vodafone.de>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>

diff --git a/drivers/gpu/drm/radeon/radeon.h b/drivers/gpu/drm/radeon/radeon.h
index 6715e4c695fab2c6ae0736813e0b871ed68eca55..2cb355bf272504d8167e8ea1f8681d8dc794dbf1 100644 (file)
--- a/drivers/gpu/drm/radeon/radeon.h
+++ b/drivers/gpu/drm/radeon/radeon.h
@@ -362,7 +362,7 @@ struct radeon_bo_list {
  * alignment).
  */
 struct radeon_sa_manager {
-       spinlock_t              lock;
+       wait_queue_head_t       wq;
        struct radeon_bo        *bo;
        struct list_head        *hole;
        struct list_head        flist[RADEON_NUM_RINGS];

diff --git a/drivers/gpu/drm/radeon/radeon_sa.c b/drivers/gpu/drm/radeon/radeon_sa.c
index 81dbb5b946ef427f49ad6379a18a5348f4e5847a..4e771240fdd0d13326ffdad3eb3ae17687a549d4 100644 (file)
--- a/drivers/gpu/drm/radeon/radeon_sa.c
+++ b/drivers/gpu/drm/radeon/radeon_sa.c
@@ -54,7 +54,7 @@ int radeon_sa_bo_manager_init(struct radeon_device *rdev,
 {
        int i, r;
 
-       spin_lock_init(&sa_manager->lock);
+       init_waitqueue_head(&sa_manager->wq);
        sa_manager->bo = NULL;
        sa_manager->size = size;
        sa_manager->domain = domain;
@@ -211,6 +211,39 @@ static bool radeon_sa_bo_try_alloc(struct radeon_sa_manager *sa_manager,
        return false;
 }
 
+/**
+ * radeon_sa_event - Check if we can stop waiting
+ *
+ * @sa_manager: pointer to the sa_manager
+ * @size: number of bytes we want to allocate
+ * @align: alignment we need to match
+ *
+ * Check if either there is a fence we can wait for or
+ * enough free memory to satisfy the allocation directly
+ */
+static bool radeon_sa_event(struct radeon_sa_manager *sa_manager,
+                           unsigned size, unsigned align)
+{
+       unsigned soffset, eoffset, wasted;
+       int i;
+
+       for (i = 0; i < RADEON_NUM_RINGS; ++i) {
+               if (!list_empty(&sa_manager->flist[i])) {
+                       return true;
+               }
+       }
+
+       soffset = radeon_sa_bo_hole_soffset(sa_manager);
+       eoffset = radeon_sa_bo_hole_eoffset(sa_manager);
+       wasted = (align - (soffset % align)) % align;
+
+       if ((eoffset - soffset) >= (size + wasted)) {
+               return true;
+       }
+
+       return false;
+}
+
 static bool radeon_sa_bo_next_hole(struct radeon_sa_manager *sa_manager,
                                   struct radeon_fence **fences,
                                   unsigned *tries)
@@ -297,8 +330,8 @@ int radeon_sa_bo_new(struct radeon_device *rdev,
        INIT_LIST_HEAD(&(*sa_bo)->olist);
        INIT_LIST_HEAD(&(*sa_bo)->flist);
 
-       spin_lock(&sa_manager->lock);
-       do {
+       spin_lock(&sa_manager->wq.lock);
+       while(1) {
                for (i = 0; i < RADEON_NUM_RINGS; ++i) {
                        fences[i] = NULL;
                        tries[i] = 0;
@@ -309,30 +342,34 @@ int radeon_sa_bo_new(struct radeon_device *rdev,
 
                        if (radeon_sa_bo_try_alloc(sa_manager, *sa_bo,
                                                   size, align)) {
-                               spin_unlock(&sa_manager->lock);
+                               spin_unlock(&sa_manager->wq.lock);
                                return 0;
                        }
 
                        /* see if we can skip over some allocations */
                } while (radeon_sa_bo_next_hole(sa_manager, fences, tries));
 
-               if (block) {
-                       spin_unlock(&sa_manager->lock);
-                       r = radeon_fence_wait_any(rdev, fences, false);
-                       spin_lock(&sa_manager->lock);
-                       if (r) {
-                               /* if we have nothing to wait for we
-                                  are practically out of memory */
-                               if (r == -ENOENT) {
-                                       r = -ENOMEM;
-                               }
-                               goto out_err;
-                       }
+               if (!block) {
+                       break;
+               }
+
+               spin_unlock(&sa_manager->wq.lock);
+               r = radeon_fence_wait_any(rdev, fences, false);
+               spin_lock(&sa_manager->wq.lock);
+               /* if we have nothing to wait for block */
+               if (r == -ENOENT) {
+                       r = wait_event_interruptible_locked(
+                               sa_manager->wq, 
+                               radeon_sa_event(sa_manager, size, align)
+                       );
+               }
+               if (r) {
+                       goto out_err;
                }
-       } while (block);
+       };
 
 out_err:
-       spin_unlock(&sa_manager->lock);
+       spin_unlock(&sa_manager->wq.lock);
        kfree(*sa_bo);
        *sa_bo = NULL;
        return r;
@@ -348,7 +385,7 @@ void radeon_sa_bo_free(struct radeon_device *rdev, struct radeon_sa_bo **sa_bo,
        }
 
        sa_manager = (*sa_bo)->manager;
-       spin_lock(&sa_manager->lock);
+       spin_lock(&sa_manager->wq.lock);
        if (fence && !radeon_fence_signaled(fence)) {
                (*sa_bo)->fence = radeon_fence_ref(fence);
                list_add_tail(&(*sa_bo)->flist,
@@ -356,7 +393,8 @@ void radeon_sa_bo_free(struct radeon_device *rdev, struct radeon_sa_bo **sa_bo,
        } else {
                radeon_sa_bo_remove_locked(*sa_bo);
        }
-       spin_unlock(&sa_manager->lock);
+       wake_up_all_locked(&sa_manager->wq);
+       spin_unlock(&sa_manager->wq.lock);
        *sa_bo = NULL;
 }
 
@@ -366,7 +404,7 @@ void radeon_sa_bo_dump_debug_info(struct radeon_sa_manager *sa_manager,
 {
        struct radeon_sa_bo *i;
 
-       spin_lock(&sa_manager->lock);
+       spin_lock(&sa_manager->wq.lock);
        list_for_each_entry(i, &sa_manager->olist, olist) {
                if (&i->olist == sa_manager->hole) {
                        seq_printf(m, ">");
@@ -381,6 +419,6 @@ void radeon_sa_bo_dump_debug_info(struct radeon_sa_manager *sa_manager,
                }
                seq_printf(m, "\n");
        }
-       spin_unlock(&sa_manager->lock);
+       spin_unlock(&sa_manager->wq.lock);
 }
 #endif