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author | Michael S. Tsirkin <mst@redhat.com> | 2012-11-01 09:16:22 +0000 |
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committer | David S. Miller <davem@davemloft.net> | 2012-11-02 21:29:57 -0400 |
commit | e19d6763cc300fcb706bd291b24ac06be71e1ce6 (patch) | |
tree | 05608ee69740360480b4c66a368eb21987993058 /include/linux/skbuff.h | |
parent | 202975b4c522c197e4e2269d389aafbf056a4c37 (diff) | |
download | linux-stable-e19d6763cc300fcb706bd291b24ac06be71e1ce6.tar.gz linux-stable-e19d6763cc300fcb706bd291b24ac06be71e1ce6.tar.bz2 linux-stable-e19d6763cc300fcb706bd291b24ac06be71e1ce6.zip |
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 <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/linux/skbuff.h')
-rw-r--r-- | include/linux/skbuff.h | 4 |
1 files changed, 3 insertions, 1 deletions
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; }; |