| Message ID | 1256667399-3149-6-git-send-email-markmc@redhat.com |
|---|---|
| State | New |
| Headers | show |
Mark McLoughlin wrote: > 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> > Could you rebase and rend this patch against master? I've got 1-4 in staging. The GSO changes make resolving this non trivial (for me at least :-)). Regards, Anthony Liguori
On Fri, 2009-10-30 at 11:21 -0500, Anthony Liguori wrote: > Mark McLoughlin wrote: > > 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> > > > > Could you rebase and rend this patch against master? I've got 1-4 in > staging. > > The GSO changes make resolving this non trivial (for me at least :-)). Um, you've lost me :-) You've got it in staging AFAICS, and anyway ... 5/5 is mostly a revert of 1/5, so if 1/5 applied so should 5/5 What's in staging looks fine to me, except it doesn't build because of problems with other patches Thanks, Mark.
Mark McLoughlin wrote: > On Fri, 2009-10-30 at 11:21 -0500, Anthony Liguori wrote: > >> Mark McLoughlin wrote: >> >>> 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> >>> >>> >> Could you rebase and rend this patch against master? I've got 1-4 in >> staging. >> >> The GSO changes make resolving this non trivial (for me at least :-)). >> > > Um, you've lost me :-) > > You've got it in staging AFAICS, and anyway ... 5/5 is mostly a revert > of 1/5, so if 1/5 applied so should 5/5 > > What's in staging looks fine to me, except it doesn't build because of > problems with other patches > Ignore it, I accidentally tried backporting the patch targeted for the stable tree and then responded to the wrong patch. Regards, Anthony Liguori
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> --- net/tap.c | 33 ++++++++++++++++++--------------- 1 files changed, 18 insertions(+), 15 deletions(-) diff --git a/net/tap.c b/net/tap.c index f32226b..5272d7d 100644 --- a/net/tap.c +++ b/net/tap.c @@ -187,23 +187,26 @@ 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)