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authorMark McLoughlin <markmc@redhat.com>2009-10-27 18:16:39 +0000
committerAnthony Liguori <aliguori@us.ibm.com>2009-11-09 08:43:02 -0600
commit5819c91806911e0976a187cf908b429ecb138da5 (patch)
treeb93a5c2cf4ebc2140f033dd08661fdf9b64ac2b6
parentcdd5cc12ba8cf0c068da319370bdd3ba45eaf7ac (diff)
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tap: drain queue in tap_send()
Okay, let's try re-enabling the drain-entire-queue behaviour, with a difference - before each subsequent packet, use qemu_can_send_packet() to check that we can send it. This is similar to how we check before polling the tap fd and avoids having to drop a packet if the receiver cannot handle it. This patch should be a performance improvement since we no longer have to go through the mainloop for each packet. Signed-off-by: Mark McLoughlin <markmc@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
-rw-r--r--net/tap.c29
1 files changed, 16 insertions, 13 deletions
diff --git a/net/tap.c b/net/tap.c
index 8cdb793..69c905c 100644
--- a/net/tap.c
+++ b/net/tap.c
@@ -188,23 +188,26 @@ static void tap_send_completed(VLANClientState *vc, ssize_t len)
static void tap_send(void *opaque)
{
TAPState *s = opaque;
- uint8_t *buf = s->buf;
int size;
- size = tap_read_packet(s->fd, s->buf, sizeof(s->buf));
- if (size <= 0) {
- return;
- }
+ do {
+ uint8_t *buf = s->buf;
- if (s->has_vnet_hdr && !s->using_vnet_hdr) {
- buf += sizeof(struct virtio_net_hdr);
- size -= sizeof(struct virtio_net_hdr);
- }
+ size = tap_read_packet(s->fd, s->buf, sizeof(s->buf));
+ if (size <= 0) {
+ break;
+ }
- size = qemu_send_packet_async(s->vc, buf, size, tap_send_completed);
- if (size == 0) {
- tap_read_poll(s, 0);
- }
+ if (s->has_vnet_hdr && !s->using_vnet_hdr) {
+ buf += sizeof(struct virtio_net_hdr);
+ size -= sizeof(struct virtio_net_hdr);
+ }
+
+ size = qemu_send_packet_async(s->vc, buf, size, tap_send_completed);
+ if (size == 0) {
+ tap_read_poll(s, 0);
+ }
+ } while (size > 0 && qemu_can_send_packet(s->vc));
}
int tap_has_ufo(VLANClientState *vc)