| Message ID | 1381429356-4292-1-git-send-email-thellstrom@vmware.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
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; > - } > - } else > - spin_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
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; - } - } else - spin_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)) {
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> --- drivers/gpu/drm/ttm/ttm_bo_vm.c | 62 +++++++++++++++++++++++++++++++-------- 1 file changed, 50 insertions(+), 12 deletions(-)