diff options
| author | Michael S. Tsirkin <mst@redhat.com> | 2012-11-01 10:16:22 +0100 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2012-11-03 02:29:57 +0100 |
| commit | e19d6763cc300fcb706bd291b24ac06be71e1ce6 (patch) | |
| tree | 05608ee69740360480b4c66a368eb21987993058 | |
| parent | Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/jkirsh... (diff) | |
| download | linux-e19d6763cc300fcb706bd291b24ac06be71e1ce6.tar.xz linux-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>
| -rw-r--r-- | drivers/vhost/vhost.c | 2 | ||||
| -rw-r--r-- | drivers/vhost/vhost.h | 2 | ||||
| -rw-r--r-- | include/linux/skbuff.h | 4 | ||||
| -rw-r--r-- | net/core/skbuff.c | 4 |
4 files changed, 7 insertions, 5 deletions
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index 99ac2cb08b43..73d08db2e677 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -1600,7 +1600,7 @@ void vhost_ubuf_put_and_wait(struct vhost_ubuf_ref *ubufs) kfree(ubufs); } -void vhost_zerocopy_callback(struct ubuf_info *ubuf) +void vhost_zerocopy_callback(struct ubuf_info *ubuf, bool status) { struct vhost_ubuf_ref *ubufs = ubuf->ctx; struct vhost_virtqueue *vq = ubufs->vq; diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h index 1125af3d27d1..2de4ce2fec40 100644 --- a/drivers/vhost/vhost.h +++ b/drivers/vhost/vhost.h @@ -191,7 +191,7 @@ bool vhost_enable_notify(struct vhost_dev *, struct vhost_virtqueue *); int vhost_log_write(struct vhost_virtqueue *vq, struct vhost_log *log, unsigned int log_num, u64 len); -void vhost_zerocopy_callback(struct ubuf_info *); +void vhost_zerocopy_callback(struct ubuf_info *, bool); int vhost_zerocopy_signal_used(struct vhost_virtqueue *vq); #define vq_err(vq, fmt, ...) do { \ 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; }; diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 6e04b1fa11f2..4abdf71a23f8 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -519,7 +519,7 @@ static void skb_release_data(struct sk_buff *skb) uarg = skb_shinfo(skb)->destructor_arg; if (uarg->callback) - uarg->callback(uarg); + uarg->callback(uarg, true); } if (skb_has_frag_list(skb)) @@ -797,7 +797,7 @@ int skb_copy_ubufs(struct sk_buff *skb, gfp_t gfp_mask) for (i = 0; i < num_frags; i++) skb_frag_unref(skb, i); - uarg->callback(uarg); + uarg->callback(uarg, false); /* skb frags point to kernel buffers */ for (i = num_frags - 1; i >= 0; i--) { |