On Thu, Oct 10, 2013 at 8:22 PM, Thomas Hellstrom thellstrom@vmware.com wrote:
Make use of the FAULT_FLAG_ALLOW_RETRY flag to allow dropping the mmap_sem while waiting for bo idle.
FAULT_FLAG_ALLOW_RETRY appears to be primarily designed for disk waits but should work just as fine for GPU waits..
Signed-off-by: Thomas Hellstrom thellstrom@vmware.com
Reviewed-by: Jakob Bornecrantz jakob@vmware.com
Tho somebody else should also take a look at this.
drivers/gpu/drm/ttm/ttm_bo_vm.c | 62 +++++++++++++++++++++++++++++++-------- 1 file changed, 50 insertions(+), 12 deletions(-)
diff --git a/drivers/gpu/drm/ttm/ttm_bo_vm.c b/drivers/gpu/drm/ttm/ttm_bo_vm.c index 1006c15..c03514b 100644 --- a/drivers/gpu/drm/ttm/ttm_bo_vm.c +++ b/drivers/gpu/drm/ttm/ttm_bo_vm.c @@ -41,6 +41,51 @@
#define TTM_BO_VM_NUM_PREFAULT 16
+static int ttm_bo_vm_fault_idle(struct ttm_buffer_object *bo,
struct vm_area_struct *vma,struct vm_fault *vmf)+{
struct ttm_bo_device *bdev = bo->bdev;int ret = 0;spin_lock(&bdev->fence_lock);if (likely(!test_bit(TTM_BO_PRIV_FLAG_MOVING, &bo->priv_flags)))goto out_unlock;/** Quick non-stalling check for idle.*/ret = ttm_bo_wait(bo, false, false, true);if (likely(ret == 0))goto out_unlock;/** If possible, avoid waiting for GPU with mmap_sem* held.*/if (vmf->flags & FAULT_FLAG_ALLOW_RETRY) {ret = VM_FAULT_RETRY;if (vmf->flags & FAULT_FLAG_RETRY_NOWAIT)goto out_unlock;up_read(&vma->vm_mm->mmap_sem);(void) ttm_bo_wait(bo, false, true, false);goto out_unlock;}/** Ordinary wait.*/ret = ttm_bo_wait(bo, false, true, false);if (unlikely(ret != 0))ret = (ret != -ERESTARTSYS) ? VM_FAULT_SIGBUS :VM_FAULT_NOPAGE;+out_unlock:
spin_unlock(&bdev->fence_lock);return ret;+}
static int ttm_bo_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf) { struct ttm_buffer_object *bo = (struct ttm_buffer_object *) @@ -91,18 +136,11 @@ static int ttm_bo_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf) * Wait for buffer data in transit, due to a pipelined * move. */
spin_lock(&bdev->fence_lock);if (test_bit(TTM_BO_PRIV_FLAG_MOVING, &bo->priv_flags)) {ret = ttm_bo_wait(bo, false, true, false);spin_unlock(&bdev->fence_lock);if (unlikely(ret != 0)) {retval = (ret != -ERESTARTSYS) ?VM_FAULT_SIGBUS : VM_FAULT_NOPAGE;goto out_unlock;}} elsespin_unlock(&bdev->fence_lock);
ret = ttm_bo_vm_fault_idle(bo, vma, vmf);if (unlikely(ret != 0)) {retval = ret;goto out_unlock;} ret = ttm_mem_io_lock(man, true); if (unlikely(ret != 0)) {-- 1.7.10.4 _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/dri-devel