| Message ID | 20190816152152.27550-1-chris@chris-wilson.co.uk (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [1/2] dma-buf: Avoid list_del during fence->cb_list iteration | expand |
Am 16.08.19 um 17:21 schrieb Chris Wilson: > Before we notify the fence signal callback, we remove the cb from the > list. However, since we are processing the entire list from underneath > the spinlock, we do not need to individual delete each element, but can > simply reset the link and the entire list. > > Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> > Cc: Daniel Vetter <daniel.vetter@ffwll.ch> > Cc: Christian König <christian.koenig@amd.com> Reviewed-by: Christian König <christian.koenig@amd.com> for the series. > --- > drivers/dma-buf/dma-fence.c | 9 ++++++--- > 1 file changed, 6 insertions(+), 3 deletions(-) > > diff --git a/drivers/dma-buf/dma-fence.c b/drivers/dma-buf/dma-fence.c > index 8025a891d3e9..ff0cd6eae766 100644 > --- a/drivers/dma-buf/dma-fence.c > +++ b/drivers/dma-buf/dma-fence.c > @@ -149,9 +149,12 @@ int dma_fence_signal_locked(struct dma_fence *fence) > trace_dma_fence_signaled(fence); > } > > - list_for_each_entry_safe(cur, tmp, &fence->cb_list, node) { > - list_del_init(&cur->node); > - cur->func(fence, cur); > + if (!list_empty(&fence->cb_list)) { > + list_for_each_entry_safe(cur, tmp, &fence->cb_list, node) { > + INIT_LIST_HEAD(&cur->node); > + cur->func(fence, cur); > + } > + INIT_LIST_HEAD(&fence->cb_list); > } > return ret; > }
diff --git a/drivers/dma-buf/dma-fence.c b/drivers/dma-buf/dma-fence.c index 8025a891d3e9..ff0cd6eae766 100644 --- a/drivers/dma-buf/dma-fence.c +++ b/drivers/dma-buf/dma-fence.c @@ -149,9 +149,12 @@ int dma_fence_signal_locked(struct dma_fence *fence) trace_dma_fence_signaled(fence); } - list_for_each_entry_safe(cur, tmp, &fence->cb_list, node) { - list_del_init(&cur->node); - cur->func(fence, cur); + if (!list_empty(&fence->cb_list)) { + list_for_each_entry_safe(cur, tmp, &fence->cb_list, node) { + INIT_LIST_HEAD(&cur->node); + cur->func(fence, cur); + } + INIT_LIST_HEAD(&fence->cb_list); } return ret; }
Before we notify the fence signal callback, we remove the cb from the list. However, since we are processing the entire list from underneath the spinlock, we do not need to individual delete each element, but can simply reset the link and the entire list. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Christian König <christian.koenig@amd.com> --- drivers/dma-buf/dma-fence.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-)