From: Rusty Russell <rusty@rustcorp.com.au> To: "Michael S. Tsirkin" <mst@redhat.com>, linux-kernel@vger.kernel.org Cc: Carsten Otte <cotte@de.ibm.com>, Christian Borntraeger <borntraeger@de.ibm.com>, linux390@de.ibm.com, Martin Schwidefsky <schwidefsky@de.ibm.com>, Heiko Carstens <heiko.carstens@de.ibm.com>, Shirley Ma <xma@us.ibm.com>, lguest@lists.ozlabs.org, linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, linux-s390@vger.kernel.org, kvm@vger.kernel.org, Krishna Kumar <krkumar2@in.ibm.com>, Tom Lendacky <tahm@linux.vnet.ibm.com>, steved@us.ibm.com, habanero@linux.vnet.ibm.com Subject: Re: [PATCHv2 11/14] virtio: don't delay avail index update Date: Sat, 21 May 2011 11:56:32 +0930 [thread overview] Message-ID: <874o4ovlev.fsf@rustcorp.com.au> (raw) In-Reply-To: <33d7df119ccbedc9b54fbe4b674076b4f7ba3499.1305846412.git.mst@redhat.com> On Fri, 20 May 2011 02:12:19 +0300, "Michael S. Tsirkin" <mst@redhat.com> wrote: > Update avail index immediately instead of upon kick: > for virtio-net RX this helps parallelism with the host. > > Signed-off-by: Michael S. Tsirkin <mst@redhat.com> > --- > drivers/virtio/virtio_ring.c | 28 +++++++++++++++++++--------- > 1 files changed, 19 insertions(+), 9 deletions(-) > > diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c > index eed5f29..8218fe6 100644 > --- a/drivers/virtio/virtio_ring.c > +++ b/drivers/virtio/virtio_ring.c > @@ -89,7 +89,7 @@ struct vring_virtqueue > unsigned int num_free; > /* Head of free buffer list. */ > unsigned int free_head; > - /* Number we've added since last sync. */ > + /* Number we've added since last kick. */ > unsigned int num_added; I always like to see obsolescent nomenclature cleaned up like this. Thanks. > /* Last used index we've seen. */ > @@ -174,6 +174,13 @@ int virtqueue_add_buf_gfp(struct virtqueue *_vq, > > BUG_ON(data == NULL); > > + /* Prevent drivers from adding more than num bufs without a kick. */ > + if (vq->num_added == vq->vring.num) { > + printk(KERN_ERR "gaaa!!!\n"); > + END_USE(vq); > + return -ENOSPC; > + } > + I like "gaaa!" but it won't tell us which driver. How about the more conventional: if (WARN_ON(vq->num_added >= vq->vring.num)) { END_USE(vq); return -ENOSPC; } I'd really like to see the results of this patch. It's useless for outgoing net traffic (we deal with one packet at a time) but perhaps a flood of incoming packets would show something. Thanks, Rusty.
WARNING: multiple messages have this Message-ID (diff)
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>, linux-kernel-u79uwXL29TY76Z2rM5mHXA@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 11/14] virtio: don't delay avail index update Date: Sat, 21 May 2011 11:56:32 +0930 [thread overview] Message-ID: <874o4ovlev.fsf@rustcorp.com.au> (raw) In-Reply-To: <33d7df119ccbedc9b54fbe4b674076b4f7ba3499.1305846412.git.mst-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> On Fri, 20 May 2011 02:12:19 +0300, "Michael S. Tsirkin" <mst-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> wrote: > Update avail index immediately instead of upon kick: > for virtio-net RX this helps parallelism with the host. > > Signed-off-by: Michael S. Tsirkin <mst-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> > --- > drivers/virtio/virtio_ring.c | 28 +++++++++++++++++++--------- > 1 files changed, 19 insertions(+), 9 deletions(-) > > diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c > index eed5f29..8218fe6 100644 > --- a/drivers/virtio/virtio_ring.c > +++ b/drivers/virtio/virtio_ring.c > @@ -89,7 +89,7 @@ struct vring_virtqueue > unsigned int num_free; > /* Head of free buffer list. */ > unsigned int free_head; > - /* Number we've added since last sync. */ > + /* Number we've added since last kick. */ > unsigned int num_added; I always like to see obsolescent nomenclature cleaned up like this. Thanks. > /* Last used index we've seen. */ > @@ -174,6 +174,13 @@ int virtqueue_add_buf_gfp(struct virtqueue *_vq, > > BUG_ON(data == NULL); > > + /* Prevent drivers from adding more than num bufs without a kick. */ > + if (vq->num_added == vq->vring.num) { > + printk(KERN_ERR "gaaa!!!\n"); > + END_USE(vq); > + return -ENOSPC; > + } > + I like "gaaa!" but it won't tell us which driver. How about the more conventional: if (WARN_ON(vq->num_added >= vq->vring.num)) { END_USE(vq); return -ENOSPC; } I'd really like to see the results of this patch. It's useless for outgoing net traffic (we deal with one packet at a time) but perhaps a flood of incoming packets would show something. Thanks, Rusty.
next prev parent reply other threads:[~2011-05-21 2:34 UTC|newest] Thread overview: 132+ messages / expand[flat|nested] mbox.gz Atom feed top 2011-05-19 23:10 [PATCHv2 00/14] virtio and vhost-net performance enhancements Michael S. Tsirkin 2011-05-19 23:10 ` Michael S. Tsirkin 2011-05-19 23:10 ` [PATCHv2 01/14] virtio: event index interface Michael S. Tsirkin 2011-05-19 23:10 ` Michael S. Tsirkin 2011-05-21 2:29 ` Rusty Russell 2011-05-21 2:29 ` Rusty Russell 2011-05-21 2:29 ` Rusty Russell 2011-05-19 23:10 ` Michael S. Tsirkin 2011-05-19 23:10 ` [PATCHv2 02/14] virtio ring: inline function to check for events Michael S. Tsirkin 2011-05-19 23:10 ` Michael S. Tsirkin 2011-05-21 2:29 ` Rusty Russell 2011-05-21 2:29 ` Rusty Russell 2011-05-21 2:29 ` Rusty Russell 2011-05-19 23:10 ` Michael S. Tsirkin 2011-05-19 23:10 ` [PATCHv2 03/14] virtio_ring: support event idx feature Michael S. Tsirkin 2011-05-19 23:10 ` Michael S. Tsirkin 2011-05-19 23:10 ` Michael S. Tsirkin 2011-05-21 2:31 ` Rusty Russell 2011-05-21 2:31 ` Rusty Russell 2011-05-21 2:31 ` Rusty Russell 2011-05-19 23:10 ` [PATCHv2 04/14] vhost: support event index Michael S. Tsirkin 2011-05-19 23:10 ` Michael S. Tsirkin 2011-05-21 2:31 ` Rusty Russell 2011-05-21 2:31 ` Rusty Russell 2011-05-21 2:31 ` Rusty Russell 2011-05-19 23:10 ` Michael S. Tsirkin 2011-05-19 23:11 ` [PATCHv2 05/14] virtio_test: " Michael S. Tsirkin 2011-05-19 23:11 ` Michael S. Tsirkin 2011-05-19 23:11 ` Michael S. Tsirkin 2011-05-21 2:32 ` Rusty Russell 2011-05-21 2:32 ` Rusty Russell 2011-05-21 2:32 ` Rusty Russell 2011-05-19 23:11 ` [PATCHv2 06/14] virtio: add api for delayed callbacks Michael S. Tsirkin 2011-05-19 23:11 ` Michael S. Tsirkin 2011-05-19 23:11 ` Michael S. Tsirkin 2011-05-21 2:33 ` Rusty Russell 2011-05-21 2:33 ` Rusty Russell 2011-05-21 2:33 ` Rusty Russell 2011-05-19 23:11 ` [PATCHv2 07/14] virtio_net: delay TX callbacks Michael S. Tsirkin 2011-05-19 23:11 ` Michael S. Tsirkin 2011-05-19 23:11 ` Michael S. Tsirkin 2011-05-19 23:11 ` [PATCHv2 08/14] virtio_ring: Add capacity check API Michael S. Tsirkin 2011-05-19 23:11 ` Michael S. Tsirkin 2011-05-19 23:11 ` Michael S. Tsirkin 2011-05-19 23:11 ` [PATCHv2 09/14] virtio_net: fix TX capacity checks using new API Michael S. Tsirkin 2011-05-19 23:11 ` Michael S. Tsirkin 2011-05-21 2:13 ` Rusty Russell 2011-05-21 2:13 ` Rusty Russell 2011-05-21 2:13 ` Rusty Russell 2011-05-19 23:11 ` Michael S. Tsirkin 2011-05-19 23:11 ` [PATCHv2 10/14] virtio_net: limit xmit polling Michael S. Tsirkin 2011-05-19 23:11 ` Michael S. Tsirkin 2011-05-21 2:19 ` Rusty Russell 2011-05-21 2:19 ` Rusty Russell 2011-05-21 2:19 ` Rusty Russell 2011-05-22 12:10 ` Michael S. Tsirkin 2011-05-22 12:10 ` Michael S. Tsirkin 2011-05-23 2:07 ` Rusty Russell 2011-05-23 2:07 ` Rusty Russell 2011-05-23 11:19 ` Michael S. Tsirkin 2011-05-23 11:19 ` Michael S. Tsirkin 2011-05-23 11:19 ` Michael S. Tsirkin 2011-05-24 7:54 ` Krishna Kumar2 2011-05-24 7:54 ` Krishna Kumar2 2011-05-24 9:12 ` Michael S. Tsirkin 2011-05-24 9:12 ` Michael S. Tsirkin 2011-05-24 9:12 ` Michael S. Tsirkin 2011-05-24 9:27 ` Krishna Kumar2 2011-05-24 9:27 ` Krishna Kumar2 2011-05-24 11:29 ` Michael S. Tsirkin 2011-05-24 11:29 ` Michael S. Tsirkin 2011-05-24 12:50 ` Krishna Kumar2 2011-05-24 12:50 ` Krishna Kumar2 2011-05-24 13:52 ` Michael S. Tsirkin 2011-05-24 13:52 ` Michael S. Tsirkin 2011-05-24 13:52 ` Michael S. Tsirkin 2011-05-24 12:50 ` Krishna Kumar2 2011-05-24 11:29 ` Michael S. Tsirkin 2011-05-24 7:54 ` Krishna Kumar2 2011-05-25 1:28 ` Rusty Russell 2011-05-25 1:28 ` Rusty Russell 2011-05-25 5:50 ` Michael S. Tsirkin 2011-05-25 5:50 ` Michael S. Tsirkin 2011-05-25 5:50 ` Michael S. Tsirkin 2011-05-25 1:28 ` Rusty Russell 2011-05-25 1:35 ` Rusty Russell 2011-05-25 1:35 ` Rusty Russell 2011-05-25 1:35 ` Rusty Russell 2011-05-25 6:07 ` Michael S. Tsirkin 2011-05-25 6:07 ` Michael S. Tsirkin 2011-05-26 3:28 ` Rusty Russell 2011-05-26 3:28 ` Rusty Russell 2011-05-26 3:28 ` Rusty Russell 2011-05-28 20:02 ` Michael S. Tsirkin 2011-05-28 20:02 ` Michael S. Tsirkin 2011-05-30 6:27 ` Rusty Russell 2011-05-30 6:27 ` Rusty Russell 2011-05-30 6:27 ` Rusty Russell 2011-05-28 20:02 ` Michael S. Tsirkin 2011-05-25 6:07 ` Michael S. Tsirkin 2011-05-23 2:07 ` Rusty Russell 2011-05-22 12:10 ` Michael S. Tsirkin 2011-05-19 23:11 ` Michael S. Tsirkin 2011-05-19 23:12 ` [PATCHv2 11/14] virtio: don't delay avail index update Michael S. Tsirkin 2011-05-19 23:12 ` Michael S. Tsirkin 2011-05-21 2:26 ` Rusty Russell 2011-05-21 2:26 ` Rusty Russell [this message] 2011-05-21 2:26 ` Rusty Russell 2011-05-19 23:12 ` Michael S. Tsirkin 2011-05-19 23:12 ` [PATCHv2 12/14] virtio: 64 bit features Michael S. Tsirkin 2011-05-19 23:12 ` Michael S. Tsirkin 2011-05-19 23:12 ` Michael S. Tsirkin 2011-05-19 23:12 ` [PATCHv2 13/14] virtio_test: update for " Michael S. Tsirkin 2011-05-19 23:12 ` Michael S. Tsirkin 2011-05-19 23:12 ` Michael S. Tsirkin 2011-05-19 23:12 ` [PATCHv2 14/14] vhost: fix " Michael S. Tsirkin 2011-05-19 23:12 ` Michael S. Tsirkin 2011-05-19 23:12 ` Michael S. Tsirkin 2011-05-19 23:20 ` [PATCHv2 00/14] virtio and vhost-net performance enhancements David Miller 2011-05-19 23:20 ` David Miller 2011-05-20 7:51 ` Rusty Russell 2011-05-20 7:51 ` Rusty Russell 2011-05-20 7:51 ` Rusty Russell 2011-05-26 15:32 ` [PERF RESULTS] " Krishna Kumar2 2011-05-26 15:32 ` Krishna Kumar2 2011-05-26 15:42 ` Shirley Ma 2011-05-26 16:21 ` Krishna Kumar2 2011-05-26 16:21 ` Krishna Kumar2 [not found] ` <OFF9D0E604.B865A006-ON6525789C.00597010-6525789C.0059987A@LocalDomain> 2011-05-26 16:29 ` Krishna Kumar2 2011-05-26 16:29 ` Krishna Kumar2 2011-05-26 16:29 ` Krishna Kumar2 2011-05-26 15:32 ` Krishna Kumar2
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=874o4ovlev.fsf@rustcorp.com.au \ --to=rusty@rustcorp.com.au \ --cc=borntraeger@de.ibm.com \ --cc=cotte@de.ibm.com \ --cc=habanero@linux.vnet.ibm.com \ --cc=heiko.carstens@de.ibm.com \ --cc=krkumar2@in.ibm.com \ --cc=kvm@vger.kernel.org \ --cc=lguest@lists.ozlabs.org \ --cc=linux-kernel@vger.kernel.org \ --cc=linux-s390@vger.kernel.org \ --cc=linux390@de.ibm.com \ --cc=mst@redhat.com \ --cc=netdev@vger.kernel.org \ --cc=schwidefsky@de.ibm.com \ --cc=steved@us.ibm.com \ --cc=tahm@linux.vnet.ibm.com \ --cc=virtualization@lists.linux-foundation.org \ --cc=xma@us.ibm.com \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.