From 3471b757d0ca63a0e8188c4c96acd1c279a8c737 Mon Sep 17 00:00:00 2001 From: Mark McLoughlin Date: Wed, 29 Apr 2009 09:50:32 +0100 Subject: [PATCH] net: only read from tapfd when we can send Reduce the number of packets dropped under heavy network traffic by only reading a packet from the tapfd when a client can actually handle it. Signed-off-by: Mark McLoughlin --- net.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/net.c b/net.c index 0d9e520..54ad98f 100644 --- a/net.c +++ b/net.c @@ -956,6 +956,13 @@ static void tap_receive(void *opaque, const uint8_t *buf, int size) } } +static int tap_can_send(void *opaque) +{ + TAPState *s = opaque; + + return qemu_can_send_packet(s->vc); +} + #ifdef __sun__ static ssize_t tap_read_packet(int tapfd, uint8_t *buf, int maxlen) { @@ -1011,7 +1018,7 @@ static TAPState *net_tap_fd_init(VLANState *vlan, s->vc = qemu_new_vlan_client(vlan, model, name, tap_receive, NULL, tap_cleanup, s); s->vc->fd_readv = tap_receive_iov; - qemu_set_fd_handler(s->fd, tap_send, NULL, s); + qemu_set_fd_handler2(s->fd, tap_can_send, tap_send, NULL, s); snprintf(s->vc->info_str, sizeof(s->vc->info_str), "fd=%d", fd); return s; } -- 2.7.4