From e19d6763cc300fcb706bd291b24ac06be71e1ce6 Mon Sep 17 00:00:00 2001 From: Michael S. Tsirkin Date: Thu, 1 Nov 2012 09:16:22 +0000 Subject: skb: report completion status for zero copy skbs Even if skb is marked for zero copy, net core might still decide to copy it later which is somewhat slower than a copy in user context: besides copying the data we need to pin/unpin the pages. Add a parameter reporting such cases through zero copy callback: if this happens a lot, device can take this into account and switch to copying in user context. This patch updates all users but ignores the passed value for now: it will be used by follow-up patches. Signed-off-by: Michael S. Tsirkin Signed-off-by: David S. Miller --- include/linux/skbuff.h | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'include/linux/skbuff.h') diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index a2a0bdb95a8f..e5eae5bc1d4d 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -235,11 +235,13 @@ enum { /* * The callback notifies userspace to release buffers when skb DMA is done in * lower device, the skb last reference should be 0 when calling this. + * The zerocopy_success argument is true if zero copy transmit occurred, + * false on data copy or out of memory error caused by data copy attempt. * The ctx field is used to track device context. * The desc field is used to track userspace buffer index. */ struct ubuf_info { - void (*callback)(struct ubuf_info *); + void (*callback)(struct ubuf_info *, bool zerocopy_success); void *ctx; unsigned long desc; }; -- cgit v1.2.3-55-g7522