From: Chris Wilson Date: Sat, 17 Aug 2019 14:47:34 +0000 (+0100) Subject: dma-fence: Avoid list_del during fence->cb_list iteration X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=f86a802bf3a7c28e4c4ea032fa2e61398dbccd5d;p=linux.git dma-fence: Avoid list_del during fence->cb_list iteration 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 Cc: Daniel Vetter Cc: Christian König Reviewed-by: Christian König Link: https://patchwork.freedesktop.org/patch/msgid/20190817144736.7826-4-chris@chris-wilson.co.uk --- diff --git a/drivers/dma-buf/dma-fence.c b/drivers/dma-buf/dma-fence.c index 8025a891d3e9e..ff0cd6eae766d 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; }