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>
This commit is contained in:
Mark McLoughlin 2009-10-27 18:16:39 +00:00 committed by Anthony Liguori
parent cdd5cc12ba
commit 5819c91806
1 changed files with 16 additions and 13 deletions

View File

@ -188,12 +188,14 @@ static void tap_send_completed(VLANClientState *vc, ssize_t len)
static void tap_send(void *opaque) static void tap_send(void *opaque)
{ {
TAPState *s = opaque; TAPState *s = opaque;
uint8_t *buf = s->buf;
int size; int size;
do {
uint8_t *buf = s->buf;
size = tap_read_packet(s->fd, s->buf, sizeof(s->buf)); size = tap_read_packet(s->fd, s->buf, sizeof(s->buf));
if (size <= 0) { if (size <= 0) {
return; break;
} }
if (s->has_vnet_hdr && !s->using_vnet_hdr) { if (s->has_vnet_hdr && !s->using_vnet_hdr) {
@ -205,6 +207,7 @@ static void tap_send(void *opaque)
if (size == 0) { if (size == 0) {
tap_read_poll(s, 0); tap_read_poll(s, 0);
} }
} while (size > 0 && qemu_can_send_packet(s->vc));
} }
int tap_has_ufo(VLANClientState *vc) int tap_has_ufo(VLANClientState *vc)