From: Rusty Russell <rusty-8n+1lVoiYb80n/F98K4Iww@public•gmane.org>
To: "Michael S. Tsirkin"
<mst-H+wXaHxf7aLQT0dZR+AlfA@public•gmane.org>,
linux-kernel-u79uwXL29TY76Z2rM5mHXA@public•gmane.org
Cc: Krishna Kumar <krkumar2-xthvdsQ13ZrQT0dZR+AlfA@public•gmane.org>,
Carsten Otte <cotte-tA70FqPdS9bQT0dZR+AlfA@public•gmane.org>,
lguest-uLR06cmDAlY/bJ5BZ2RsiQ@public•gmane.org,
Shirley Ma <xma-r/Jw6+rmf7HQT0dZR+AlfA@public•gmane.org>,
kvm-u79uwXL29TY76Z2rM5mHXA@public•gmane.org,
linux-s390-u79uwXL29TY76Z2rM5mHXA@public•gmane.org,
netdev-u79uwXL29TY76Z2rM5mHXA@public•gmane.org,
habanero-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public•gmane.org,
Heiko Carstens
<heiko.carstens-tA70FqPdS9bQT0dZR+AlfA@public•gmane.org>,
virtualization-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public•gmane.org,
steved-r/Jw6+rmf7HQT0dZR+AlfA@public•gmane.org,
Christian Borntraeger
<borntraeger-tA70FqPdS9bQT0dZR+AlfA@public•gmane.org>,
Tom Lendacky
<tahm-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public•gmane.org>,
Martin Schwidefsky
<schwidefsky-tA70FqPdS9bQT0dZR+AlfA@public•gmane.org>,
linux390-tA70FqPdS9bQT0dZR+AlfA@public•gmane.org
Subject: Re: [PATCHv2 RFC 0/4] virtio and vhost-net capacity handling
Date: Mon, 06 Jun 2011 13:09:35 +0930 [thread overview]
Message-ID: <87fwnniq6f.fsf@rustcorp.com.au> (raw)
In-Reply-To: <20110602171721.GA13215-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
On Thu, 2 Jun 2011 20:17:21 +0300, "Michael S. Tsirkin" <mst-H+wXaHxf7aLQT0dZR+AlfA@public•gmane.org> wrote:
> On Thu, Jun 02, 2011 at 06:42:35PM +0300, Michael S. Tsirkin wrote:
> > OK, here's a new attempt to use the new capacity api. I also added more
> > comments to clarify the logic. Hope this is more readable. Let me know
> > pls.
> >
> > This is on top of the patches applied by Rusty.
> >
> > Warning: untested. Posting now to give people chance to
> > comment on the API.
> >
> > Changes from v1:
> > - fix comment in patch 2 to correct confusion noted by Rusty
> > - rewrite patch 3 along the lines suggested by Rusty
> > note: it's not exactly the same but I hope it's close
> > enough, the main difference is that mine does limited
> > polling even in the unlikely xmit failure case.
> > - added a patch to not return capacity from add_buf
> > it always looked like a weird hack
> >
> > Michael S. Tsirkin (4):
> > virtio_ring: add capacity check API
> > virtio_net: fix tx capacity checks using new API
> > virtio_net: limit xmit polling
> > Revert "virtio: make add_buf return capacity remaining:
> >
> > drivers/net/virtio_net.c | 111 ++++++++++++++++++++++++++----------------
> > drivers/virtio/virtio_ring.c | 10 +++-
> > include/linux/virtio.h | 7 ++-
> > 3 files changed, 84 insertions(+), 44 deletions(-)
> >
> > --
> > 1.7.5.53.gc233e
>
>
> And just FYI, here's a patch (on top) that I considered but
> decided against. This does a single get_buf before
> xmit. I thought it's not really needed as the capacity
> check in add_buf is relatively cheap, and we removed
> the kick in xmit_skb. But the point is that the loop
> will now be easy to move around if someone manages
> to show this benefits speed (which I doubt).
Agreed. The other is clearer.
I like the approach these patches take. Testing is required, but I
think the final result is a neater driver than the current one, as well
as having nicer latency.
Thanks,
Rusty.
next prev parent reply other threads:[~2011-06-06 3:39 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-06-02 15:42 [PATCHv2 RFC 0/4] virtio and vhost-net capacity handling Michael S. Tsirkin
[not found] ` <cover.1307029008.git.mst-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2011-06-02 15:42 ` [PATCHv2 RFC 1/4] virtio_ring: add capacity check API Michael S. Tsirkin
2011-06-02 15:43 ` [PATCHv2 RFC 2/4] virtio_net: fix tx capacity checks using new API Michael S. Tsirkin
2011-06-02 15:43 ` [PATCHv2 RFC 3/4] virtio_net: limit xmit polling Michael S. Tsirkin
2011-06-02 18:09 ` Sridhar Samudrala
[not found] ` <1307038193.2321.38.camel-gzECXbv5Qf5llG67XfQwVQGz3MnDiSnoQQ4Iyu8u01E@public.gmane.org>
2011-06-02 19:23 ` Michael S. Tsirkin
[not found] ` <a80199422de16ae355e56ee1b2abc9b2bf91a7f6.1307029009.git.mst-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2011-06-07 15:59 ` Michael S. Tsirkin
2011-06-02 15:43 ` [PATCHv2 RFC 4/4] Revert "virtio: make add_buf return capacity remaining: Michael S. Tsirkin
[not found] ` <7572d6fb81181e349af4a8b203ea0977f6e91ae1.1307029009.git.mst-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2011-06-07 15:54 ` Michael S. Tsirkin
2011-06-08 0:19 ` Rusty Russell
2011-06-02 17:17 ` [PATCHv2 RFC 0/4] virtio and vhost-net capacity handling Michael S. Tsirkin
[not found] ` <20110602171721.GA13215-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2011-06-06 3:39 ` Rusty Russell [this message]
2011-06-07 16:08 ` Michael S. Tsirkin
2011-06-13 13:32 ` Krishna Kumar2
[not found] ` <OFE36F9C2B.43D9DB04-ON652578AE.0048E1AB-652578AE.004A1462-xthvdsQ13ZrQT0dZR+AlfA@public.gmane.org>
2011-06-13 13:35 ` Michael S. Tsirkin
[not found] ` <20110613133513.GA29884-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2011-06-13 13:44 ` Krishna Kumar2
2011-06-13 13:38 ` Krishna Kumar2
2011-06-19 8:53 ` Michael S. Tsirkin
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