From 5d8c7a434af03805e3d4b4a5913f488a1ae7a53b Mon Sep 17 00:00:00 2001 From: Mark McLoughlin Date: Tue, 27 Oct 2009 18:16:39 +0000 Subject: [PATCH] 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 Signed-off-by: Anthony Liguori --- net/tap.c | 29 ++++++++++++++++------------- 1 file 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) -- 2.7.4