2013-07-08 10:11:52

by Michael S. Tsirkin

[permalink] [raw]
Subject: [PATCH] virtio-net: put virtio net header inline with data

For small packets we can simplify xmit processing
by linearizing buffers with the header:
most packets seem to have enough head room
we can use for this purpose.
Since existing hypervisors require that header
is the first s/g element, we need a feature bit
for this.

Signed-off-by: Michael S. Tsirkin <[email protected]>
---

Note: this needs to be applied on top of patch
defining VIRTIO_F_ANY_LAYOUT - bit to be
selected by Rusty.

The following patch should work for any definition of
VIRTIO_F_ANY_LAYOUT - I used bit 31 for testing.
Rusty, could you please pick a valid bit for VIRTIO_F_ANY_LAYOUT
and squeeze this patch into 3.11?

drivers/net/virtio_net.c | 42 +++++++++++++++++++++++++++++++++--------
include/uapi/linux/virtio_net.h | 4 +++-
2 files changed, 37 insertions(+), 9 deletions(-)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index c9e0038..5305bd1 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -106,6 +106,9 @@ struct virtnet_info {
/* Has control virtqueue */
bool has_cvq;

+ /* Host can handle any s/g split between our header and packet data */
+ bool any_header_sg;
+
/* enable config space updates */
bool config_enable;

@@ -668,12 +671,28 @@ static void free_old_xmit_skbs(struct send_queue *sq)

static int xmit_skb(struct send_queue *sq, struct sk_buff *skb)
{
- struct skb_vnet_hdr *hdr = skb_vnet_hdr(skb);
+ struct skb_vnet_hdr *hdr;
const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest;
struct virtnet_info *vi = sq->vq->vdev->priv;
unsigned num_sg;
+ unsigned hdr_len;
+ bool can_push;

pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest);
+ if (vi->mergeable_rx_bufs)
+ hdr_len = sizeof hdr->mhdr;
+ else
+ hdr_len = sizeof hdr->hdr;
+
+ can_push = vi->any_header_sg &&
+ !((unsigned long)skb->data & (__alignof__(*hdr) - 1)) &&
+ !skb_header_cloned(skb) && skb_headroom(skb) >= hdr_len;
+ /* Even if we can, don't push here yet as this would skew
+ * csum_start offset below. */
+ if (can_push)
+ hdr = (struct skb_vnet_hdr *)(skb->data - hdr_len);
+ else
+ hdr = skb_vnet_hdr(skb);

if (skb->ip_summed == CHECKSUM_PARTIAL) {
hdr->hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
@@ -702,15 +721,18 @@ static int xmit_skb(struct send_queue *sq, struct sk_buff *skb)
hdr->hdr.gso_size = hdr->hdr.hdr_len = 0;
}

- hdr->mhdr.num_buffers = 0;
-
- /* Encode metadata header at front. */
if (vi->mergeable_rx_bufs)
- sg_set_buf(sq->sg, &hdr->mhdr, sizeof hdr->mhdr);
- else
- sg_set_buf(sq->sg, &hdr->hdr, sizeof hdr->hdr);
+ hdr->mhdr.num_buffers = 0;

- num_sg = skb_to_sgvec(skb, sq->sg + 1, 0, skb->len) + 1;
+ if (can_push) {
+ __skb_push(skb, hdr_len);
+ num_sg = skb_to_sgvec(skb, sq->sg, 0, skb->len);
+ /* Pull header back to avoid skew in tx bytes calculations. */
+ __skb_pull(skb, hdr_len);
+ } else {
+ sg_set_buf(sq->sg, hdr, hdr_len);
+ num_sg = skb_to_sgvec(skb, sq->sg + 1, 0, skb->len) + 1;
+ }
return virtqueue_add_outbuf(sq->vq, sq->sg, num_sg, skb, GFP_ATOMIC);
}

@@ -1554,6 +1576,9 @@ static int virtnet_probe(struct virtio_device *vdev)
if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF))
vi->mergeable_rx_bufs = true;

+ if (virtio_has_feature(vdev, VIRTIO_F_ANY_LAYOUT))
+ vi->any_header_sg = true;
+
if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ))
vi->has_cvq = true;

@@ -1729,6 +1754,7 @@ static unsigned int features[] = {
VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_VLAN,
VIRTIO_NET_F_GUEST_ANNOUNCE, VIRTIO_NET_F_MQ,
VIRTIO_NET_F_CTRL_MAC_ADDR,
+ VIRTIO_F_ANY_LAYOUT,
};

static struct virtio_driver virtio_net_driver = {
diff --git a/include/uapi/linux/virtio_net.h b/include/uapi/linux/virtio_net.h
index c520203..bd1993b 100644
--- a/include/uapi/linux/virtio_net.h
+++ b/include/uapi/linux/virtio_net.h
@@ -70,7 +70,9 @@ struct virtio_net_config {
__u16 max_virtqueue_pairs;
} __attribute__((packed));

-/* This is the first element of the scatter-gather list. If you don't
+/* This header comes first in the scatter-gather list.
+ * If VIRTIO_F_ANY_LAYOUT is not negotiated, it must
+ * be the first element of the scatter-gather list. If you don't
* specify GSO or CSUM features, you can simply ignore the header. */
struct virtio_net_hdr {
#define VIRTIO_NET_HDR_F_NEEDS_CSUM 1 // Use csum_start, csum_offset
--
MST


2013-07-09 02:17:02

by Rusty Russell

[permalink] [raw]
Subject: Re: [PATCH] virtio-net: put virtio net header inline with data

"Michael S. Tsirkin" <[email protected]> writes:
> For small packets we can simplify xmit processing
> by linearizing buffers with the header:
> most packets seem to have enough head room
> we can use for this purpose.
> Since existing hypervisors require that header
> is the first s/g element, we need a feature bit
> for this.
>
> Signed-off-by: Michael S. Tsirkin <[email protected]>
> ---
>
> Note: this needs to be applied on top of patch
> defining VIRTIO_F_ANY_LAYOUT - bit to be
> selected by Rusty.
>
> The following patch should work for any definition of
> VIRTIO_F_ANY_LAYOUT - I used bit 31 for testing.
> Rusty, could you please pick a valid bit for VIRTIO_F_ANY_LAYOUT
> and squeeze this patch into 3.11?

Sorry, it's too late.

First, I've been a bit lax in sending patches via DaveM, and this is
definitely his territory (ie. more net than virtio).

Secondly, it needs baking and testing time.

Cheers,
Rusty.

2013-07-09 05:17:21

by Michael S. Tsirkin

[permalink] [raw]
Subject: Re: [PATCH] virtio-net: put virtio net header inline with data

On Tue, Jul 09, 2013 at 11:46:23AM +0930, Rusty Russell wrote:
> "Michael S. Tsirkin" <[email protected]> writes:
> > For small packets we can simplify xmit processing
> > by linearizing buffers with the header:
> > most packets seem to have enough head room
> > we can use for this purpose.
> > Since existing hypervisors require that header
> > is the first s/g element, we need a feature bit
> > for this.
> >
> > Signed-off-by: Michael S. Tsirkin <[email protected]>
> > ---
> >
> > Note: this needs to be applied on top of patch
> > defining VIRTIO_F_ANY_LAYOUT - bit to be
> > selected by Rusty.
> >
> > The following patch should work for any definition of
> > VIRTIO_F_ANY_LAYOUT - I used bit 31 for testing.
> > Rusty, could you please pick a valid bit for VIRTIO_F_ANY_LAYOUT
> > and squeeze this patch into 3.11?
>
> Sorry, it's too late.
>
> First, I've been a bit lax in sending patches via DaveM, and this is
> definitely his territory (ie. more net than virtio).

Let's do this: I'll send a patch series, you ack and we see
what happens?

> Secondly, it needs baking and testing time.
>
> Cheers,
> Rusty.

I did some testing on this. But proper testing just isn't happening out
of tree.

--
MST

2013-07-10 01:49:43

by Rusty Russell

[permalink] [raw]
Subject: Re: [PATCH] virtio-net: put virtio net header inline with data

"Michael S. Tsirkin" <[email protected]> writes:
> On Tue, Jul 09, 2013 at 11:46:23AM +0930, Rusty Russell wrote:
>> "Michael S. Tsirkin" <[email protected]> writes:
>> > For small packets we can simplify xmit processing
>> > by linearizing buffers with the header:
>> > most packets seem to have enough head room
>> > we can use for this purpose.
>> > Since existing hypervisors require that header
>> > is the first s/g element, we need a feature bit
>> > for this.
>> >
>> > Signed-off-by: Michael S. Tsirkin <[email protected]>
>> > ---
>> >
>> > Note: this needs to be applied on top of patch
>> > defining VIRTIO_F_ANY_LAYOUT - bit to be
>> > selected by Rusty.
>> >
>> > The following patch should work for any definition of
>> > VIRTIO_F_ANY_LAYOUT - I used bit 31 for testing.
>> > Rusty, could you please pick a valid bit for VIRTIO_F_ANY_LAYOUT
>> > and squeeze this patch into 3.11?
>>
>> Sorry, it's too late.
>>
>> First, I've been a bit lax in sending patches via DaveM, and this is
>> definitely his territory (ie. more net than virtio).
>
> Let's do this: I'll send a patch series, you ack and we see
> what happens?

If you convince DaveM, I won't object :)

>> Secondly, it needs baking and testing time.
>>
>> Cheers,
>> Rusty.
>
> I did some testing on this. But proper testing just isn't happening out
> of tree.

But it will get into linux-next for the *next* merge window.

Cheers,
Rusty.

2013-07-10 04:38:10

by David Miller

[permalink] [raw]
Subject: Re: [PATCH] virtio-net: put virtio net header inline with data

From: Rusty Russell <[email protected]>
Date: Tue, 09 Jul 2013 17:38:51 +0930

> If you convince DaveM, I won't object :)

Simplifications are great, but not when the merge window opens up.

Sorry, this isn't appropriate now.

2013-07-10 06:12:59

by Michael S. Tsirkin

[permalink] [raw]
Subject: Re: [PATCH] virtio-net: put virtio net header inline with data

On Tue, Jul 09, 2013 at 05:38:51PM +0930, Rusty Russell wrote:
> "Michael S. Tsirkin" <[email protected]> writes:
> > On Tue, Jul 09, 2013 at 11:46:23AM +0930, Rusty Russell wrote:
> >> "Michael S. Tsirkin" <[email protected]> writes:
> >> > For small packets we can simplify xmit processing
> >> > by linearizing buffers with the header:
> >> > most packets seem to have enough head room
> >> > we can use for this purpose.
> >> > Since existing hypervisors require that header
> >> > is the first s/g element, we need a feature bit
> >> > for this.
> >> >
> >> > Signed-off-by: Michael S. Tsirkin <[email protected]>
> >> > ---
> >> >
> >> > Note: this needs to be applied on top of patch
> >> > defining VIRTIO_F_ANY_LAYOUT - bit to be
> >> > selected by Rusty.
> >> >
> >> > The following patch should work for any definition of
> >> > VIRTIO_F_ANY_LAYOUT - I used bit 31 for testing.
> >> > Rusty, could you please pick a valid bit for VIRTIO_F_ANY_LAYOUT
> >> > and squeeze this patch into 3.11?
> >>
> >> Sorry, it's too late.
> >>
> >> First, I've been a bit lax in sending patches via DaveM, and this is
> >> definitely his territory (ie. more net than virtio).
> >
> > Let's do this: I'll send a patch series, you ack and we see
> > what happens?
>
> If you convince DaveM, I won't object :)
>
> >> Secondly, it needs baking and testing time.
> >>
> >> Cheers,
> >> Rusty.
> >
> > I did some testing on this. But proper testing just isn't happening out
> > of tree.
>
> But it will get into linux-next for the *next* merge window.
>
> Cheers,
> Rusty.

Okay. Can you put it on virtio-next then?
I don't see it there ...

--
MST

2013-07-11 12:59:02

by Michael S. Tsirkin

[permalink] [raw]
Subject: Re: [PATCH] virtio-net: put virtio net header inline with data

On Tue, Jul 09, 2013 at 11:46:23AM +0930, Rusty Russell wrote:
> "Michael S. Tsirkin" <[email protected]> writes:
> > For small packets we can simplify xmit processing
> > by linearizing buffers with the header:
> > most packets seem to have enough head room
> > we can use for this purpose.
> > Since existing hypervisors require that header
> > is the first s/g element, we need a feature bit
> > for this.
> >
> > Signed-off-by: Michael S. Tsirkin <[email protected]>
> > ---
> >
> > Note: this needs to be applied on top of patch
> > defining VIRTIO_F_ANY_LAYOUT - bit to be
> > selected by Rusty.
> >
> > The following patch should work for any definition of
> > VIRTIO_F_ANY_LAYOUT - I used bit 31 for testing.
> > Rusty, could you please pick a valid bit for VIRTIO_F_ANY_LAYOUT
> > and squeeze this patch into 3.11?
>
> Sorry, it's too late.
>
> First, I've been a bit lax in sending patches via DaveM, and this is
> definitely his territory (ie. more net than virtio).
>
> Secondly, it needs baking and testing time.
>
> Cheers,
> Rusty.

Okay. But we can already commit the qemu change, right?
Also, can you submit the spec update please?

2013-07-12 06:02:10

by Rusty Russell

[permalink] [raw]
Subject: Re: [PATCH] virtio-net: put virtio net header inline with data

"Michael S. Tsirkin" <[email protected]> writes:
> On Tue, Jul 09, 2013 at 11:46:23AM +0930, Rusty Russell wrote:
>> "Michael S. Tsirkin" <[email protected]> writes:
>> > For small packets we can simplify xmit processing
>> > by linearizing buffers with the header:
>> > most packets seem to have enough head room
>> > we can use for this purpose.
>> > Since existing hypervisors require that header
>> > is the first s/g element, we need a feature bit
>> > for this.
>> >
>> > Signed-off-by: Michael S. Tsirkin <[email protected]>
>> > ---
>> >
>> > Note: this needs to be applied on top of patch
>> > defining VIRTIO_F_ANY_LAYOUT - bit to be
>> > selected by Rusty.
>> >
>> > The following patch should work for any definition of
>> > VIRTIO_F_ANY_LAYOUT - I used bit 31 for testing.
>> > Rusty, could you please pick a valid bit for VIRTIO_F_ANY_LAYOUT
>> > and squeeze this patch into 3.11?
>>
>> Sorry, it's too late.
>>
>> First, I've been a bit lax in sending patches via DaveM, and this is
>> definitely his territory (ie. more net than virtio).
>>
>> Secondly, it needs baking and testing time.
>>
>> Cheers,
>> Rusty.
>
> Okay. But we can already commit the qemu change, right?
> Also, can you submit the spec update please?

The spec has been updated, BTW.

Cheers,
Rusty.

2013-07-15 04:23:40

by Rusty Russell

[permalink] [raw]
Subject: [PATCH] virtio-net: put virtio net header inline with data

From: Michael S. Tsirkin <[email protected]>

For small packets we can simplify xmit processing
by linearizing buffers with the header:
most packets seem to have enough head room
we can use for this purpose.
Since existing hypervisors require that header
is the first s/g element, we need a feature bit
for this.

Signed-off-by: Michael S. Tsirkin <[email protected]>
Signed-off-by: Rusty Russell <[email protected]>
---
drivers/net/virtio_net.c | 42 +++++++++++++++++++++++++++++++++--------
include/uapi/linux/virtio_net.h | 4 +++-
2 files changed, 37 insertions(+), 9 deletions(-)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 3d2a90a..f216002 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -106,6 +106,9 @@ struct virtnet_info {
/* Has control virtqueue */
bool has_cvq;

+ /* Host can handle any s/g split between our header and packet data */
+ bool any_header_sg;
+
/* enable config space updates */
bool config_enable;

@@ -669,12 +672,28 @@ static void free_old_xmit_skbs(struct send_queue *sq)

static int xmit_skb(struct send_queue *sq, struct sk_buff *skb)
{
- struct skb_vnet_hdr *hdr = skb_vnet_hdr(skb);
+ struct skb_vnet_hdr *hdr;
const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest;
struct virtnet_info *vi = sq->vq->vdev->priv;
unsigned num_sg;
+ unsigned hdr_len;
+ bool can_push;

pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest);
+ if (vi->mergeable_rx_bufs)
+ hdr_len = sizeof hdr->mhdr;
+ else
+ hdr_len = sizeof hdr->hdr;
+
+ can_push = vi->any_header_sg &&
+ !((unsigned long)skb->data & (__alignof__(*hdr) - 1)) &&
+ !skb_header_cloned(skb) && skb_headroom(skb) >= hdr_len;
+ /* Even if we can, don't push here yet as this would skew
+ * csum_start offset below. */
+ if (can_push)
+ hdr = (struct skb_vnet_hdr *)(skb->data - hdr_len);
+ else
+ hdr = skb_vnet_hdr(skb);

if (skb->ip_summed == CHECKSUM_PARTIAL) {
hdr->hdr.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
@@ -703,15 +722,18 @@ static int xmit_skb(struct send_queue *sq, struct sk_buff *skb)
hdr->hdr.gso_size = hdr->hdr.hdr_len = 0;
}

- hdr->mhdr.num_buffers = 0;
-
- /* Encode metadata header at front. */
if (vi->mergeable_rx_bufs)
- sg_set_buf(sq->sg, &hdr->mhdr, sizeof hdr->mhdr);
- else
- sg_set_buf(sq->sg, &hdr->hdr, sizeof hdr->hdr);
+ hdr->mhdr.num_buffers = 0;

- num_sg = skb_to_sgvec(skb, sq->sg + 1, 0, skb->len) + 1;
+ if (can_push) {
+ __skb_push(skb, hdr_len);
+ num_sg = skb_to_sgvec(skb, sq->sg, 0, skb->len);
+ /* Pull header back to avoid skew in tx bytes calculations. */
+ __skb_pull(skb, hdr_len);
+ } else {
+ sg_set_buf(sq->sg, hdr, hdr_len);
+ num_sg = skb_to_sgvec(skb, sq->sg + 1, 0, skb->len) + 1;
+ }
return virtqueue_add_outbuf(sq->vq, sq->sg, num_sg, skb, GFP_ATOMIC);
}

@@ -1552,6 +1574,9 @@ static int virtnet_probe(struct virtio_device *vdev)
if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF))
vi->mergeable_rx_bufs = true;

+ if (virtio_has_feature(vdev, VIRTIO_F_ANY_LAYOUT))
+ vi->any_header_sg = true;
+
if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ))
vi->has_cvq = true;

@@ -1727,6 +1752,7 @@ static unsigned int features[] = {
VIRTIO_NET_F_CTRL_RX, VIRTIO_NET_F_CTRL_VLAN,
VIRTIO_NET_F_GUEST_ANNOUNCE, VIRTIO_NET_F_MQ,
VIRTIO_NET_F_CTRL_MAC_ADDR,
+ VIRTIO_F_ANY_LAYOUT,
};

static struct virtio_driver virtio_net_driver = {
diff --git a/include/uapi/linux/virtio_net.h b/include/uapi/linux/virtio_net.h
index c520203..227d4ce 100644
--- a/include/uapi/linux/virtio_net.h
+++ b/include/uapi/linux/virtio_net.h
@@ -70,7 +70,9 @@ struct virtio_net_config {
__u16 max_virtqueue_pairs;
} __attribute__((packed));

-/* This is the first element of the scatter-gather list. If you don't
+/* This header comes first in the scatter-gather list.
+ * If VIRTIO_F_ANY_LAYOUT is not negotiated, it must
+ * be the first element of the scatter-gather list. If you don't
* specify GSO or CSUM features, you can simply ignore the header. */
struct virtio_net_hdr {
#define VIRTIO_NET_HDR_F_NEEDS_CSUM 1 // Use csum_start, csum_offset

2013-07-15 04:23:39

by Rusty Russell

[permalink] [raw]
Subject: Re: [PATCH] virtio-net: put virtio net header inline with data

"Michael S. Tsirkin" <[email protected]> writes:
> On Tue, Jul 09, 2013 at 05:38:51PM +0930, Rusty Russell wrote:
>> "Michael S. Tsirkin" <[email protected]> writes:
>> > On Tue, Jul 09, 2013 at 11:46:23AM +0930, Rusty Russell wrote:
>> >> "Michael S. Tsirkin" <[email protected]> writes:
>> >> > For small packets we can simplify xmit processing
>> >> > by linearizing buffers with the header:
>> >> > most packets seem to have enough head room
>> >> > we can use for this purpose.
>> >> > Since existing hypervisors require that header
>> >> > is the first s/g element, we need a feature bit
>> >> > for this.
>> >> >
>> >> > Signed-off-by: Michael S. Tsirkin <[email protected]>
>> >> > ---
>> >> >
>> >> > Note: this needs to be applied on top of patch
>> >> > defining VIRTIO_F_ANY_LAYOUT - bit to be
>> >> > selected by Rusty.
>> >> >
>> >> > The following patch should work for any definition of
>> >> > VIRTIO_F_ANY_LAYOUT - I used bit 31 for testing.
>> >> > Rusty, could you please pick a valid bit for VIRTIO_F_ANY_LAYOUT
>> >> > and squeeze this patch into 3.11?
>> >>
>> >> Sorry, it's too late.
>> >>
>> >> First, I've been a bit lax in sending patches via DaveM, and this is
>> >> definitely his territory (ie. more net than virtio).
>> >
>> > Let's do this: I'll send a patch series, you ack and we see
>> > what happens?
>>
>> If you convince DaveM, I won't object :)
>>
>> >> Secondly, it needs baking and testing time.
>> >>
>> >> Cheers,
>> >> Rusty.
>> >
>> > I did some testing on this. But proper testing just isn't happening out
>> > of tree.
>>
>> But it will get into linux-next for the *next* merge window.
>>
>> Cheers,
>> Rusty.
>
> Okay. Can you put it on virtio-next then?
> I don't see it there ...

Here's the general order:
- 1 week before Linus merge window: I stop putting new stuff into xxx-next.
- Linus merge window open: I push stuff to Linus, new stuff stays in -pending.
- Linus merge window close: I ff my -next trees to -rc1, merge stuff
from -pending.

In this case, your patch will go from pending-rebases to DaveM, not
virtio-next.

Which I will do now...

Cheers,
Rusty.

2013-07-16 19:33:29

by David Miller

[permalink] [raw]
Subject: Re: [PATCH] virtio-net: put virtio net header inline with data

From: Rusty Russell <[email protected]>
Date: Mon, 15 Jul 2013 11:13:25 +0930

> From: Michael S. Tsirkin <[email protected]>
>
> For small packets we can simplify xmit processing
> by linearizing buffers with the header:
> most packets seem to have enough head room
> we can use for this purpose.
> Since existing hypervisors require that header
> is the first s/g element, we need a feature bit
> for this.
>
> Signed-off-by: Michael S. Tsirkin <[email protected]>
> Signed-off-by: Rusty Russell <[email protected]>

I really think this has to wait until the next merge window, sorry.

Please resubmit this when I open net-next back up, thanks.

2013-07-17 01:03:47

by Rusty Russell

[permalink] [raw]
Subject: Re: [PATCH] virtio-net: put virtio net header inline with data

David Miller <[email protected]> writes:
> From: Rusty Russell <[email protected]>
> Date: Mon, 15 Jul 2013 11:13:25 +0930
>
>> From: Michael S. Tsirkin <[email protected]>
>>
>> For small packets we can simplify xmit processing
>> by linearizing buffers with the header:
>> most packets seem to have enough head room
>> we can use for this purpose.
>> Since existing hypervisors require that header
>> is the first s/g element, we need a feature bit
>> for this.
>>
>> Signed-off-by: Michael S. Tsirkin <[email protected]>
>> Signed-off-by: Rusty Russell <[email protected]>
>
> I really think this has to wait until the next merge window, sorry.
>
> Please resubmit this when I open net-next back up, thanks.

Oh, assumed it was already open. Will re-submit then.

Cheers,
Rusty.

2013-07-17 04:59:22

by Michael S. Tsirkin

[permalink] [raw]
Subject: Re: [PATCH] virtio-net: put virtio net header inline with data

On Tue, Jul 16, 2013 at 12:33:26PM -0700, David Miller wrote:
> From: Rusty Russell <[email protected]>
> Date: Mon, 15 Jul 2013 11:13:25 +0930
>
> > From: Michael S. Tsirkin <[email protected]>
> >
> > For small packets we can simplify xmit processing
> > by linearizing buffers with the header:
> > most packets seem to have enough head room
> > we can use for this purpose.
> > Since existing hypervisors require that header
> > is the first s/g element, we need a feature bit
> > for this.
> >
> > Signed-off-by: Michael S. Tsirkin <[email protected]>
> > Signed-off-by: Rusty Russell <[email protected]>
>
> I really think this has to wait until the next merge window, sorry.
>
> Please resubmit this when I open net-next back up, thanks.

I assumed since -rc1 is out net-next is already open?

2013-07-17 05:05:31

by David Miller

[permalink] [raw]
Subject: Re: [PATCH] virtio-net: put virtio net header inline with data

From: "Michael S. Tsirkin" <[email protected]>
Date: Wed, 17 Jul 2013 08:00:32 +0300

> On Tue, Jul 16, 2013 at 12:33:26PM -0700, David Miller wrote:
>> From: Rusty Russell <[email protected]>
>> Date: Mon, 15 Jul 2013 11:13:25 +0930
>>
>> > From: Michael S. Tsirkin <[email protected]>
>> >
>> > For small packets we can simplify xmit processing
>> > by linearizing buffers with the header:
>> > most packets seem to have enough head room
>> > we can use for this purpose.
>> > Since existing hypervisors require that header
>> > is the first s/g element, we need a feature bit
>> > for this.
>> >
>> > Signed-off-by: Michael S. Tsirkin <[email protected]>
>> > Signed-off-by: Rusty Russell <[email protected]>
>>
>> I really think this has to wait until the next merge window, sorry.
>>
>> Please resubmit this when I open net-next back up, thanks.
>
> I assumed since -rc1 is out net-next is already open?

-rc1 being released never makes net-next open. Instead, I explicitly
open it up at some point in time after -rc1 when I feel that things
have settled down enough.

And when that happens, I announce so here.

So you have to follow my announcements here on netdev to know
when net-next is actually open.

2013-07-18 01:23:45

by Rusty Russell

[permalink] [raw]
Subject: Re: [PATCH] virtio-net: put virtio net header inline with data

David Miller <[email protected]> writes:
> From: "Michael S. Tsirkin" <[email protected]>
> Date: Wed, 17 Jul 2013 08:00:32 +0300
>
>> On Tue, Jul 16, 2013 at 12:33:26PM -0700, David Miller wrote:
>>> From: Rusty Russell <[email protected]>
>>> Date: Mon, 15 Jul 2013 11:13:25 +0930
>>>
>>> > From: Michael S. Tsirkin <[email protected]>
>>> >
>>> > For small packets we can simplify xmit processing
>>> > by linearizing buffers with the header:
>>> > most packets seem to have enough head room
>>> > we can use for this purpose.
>>> > Since existing hypervisors require that header
>>> > is the first s/g element, we need a feature bit
>>> > for this.
>>> >
>>> > Signed-off-by: Michael S. Tsirkin <[email protected]>
>>> > Signed-off-by: Rusty Russell <[email protected]>
>>>
>>> I really think this has to wait until the next merge window, sorry.
>>>
>>> Please resubmit this when I open net-next back up, thanks.
>>
>> I assumed since -rc1 is out net-next is already open?
>
> -rc1 being released never makes net-next open. Instead, I explicitly
> open it up at some point in time after -rc1 when I feel that things
> have settled down enough.
>
> And when that happens, I announce so here.
>
> So you have to follow my announcements here on netdev to know
> when net-next is actually open.

Thanks for letting me know. I'm sure that works well for others, but I
can't follow the mailing lists of every maintainer I deal with.

Fortunately, you're the paragon for acking applied patches, so if I hit
this failure mode again I will know.

Cheers,
Rusty.

2013-07-24 19:43:32

by Michael S. Tsirkin

[permalink] [raw]
Subject: Re: [PATCH] virtio-net: put virtio net header inline with data

On Wed, Jul 17, 2013 at 03:32:36PM +0930, Rusty Russell wrote:
> David Miller <[email protected]> writes:
> > From: "Michael S. Tsirkin" <[email protected]>
> > Date: Wed, 17 Jul 2013 08:00:32 +0300
> >
> >> On Tue, Jul 16, 2013 at 12:33:26PM -0700, David Miller wrote:
> >>> From: Rusty Russell <[email protected]>
> >>> Date: Mon, 15 Jul 2013 11:13:25 +0930
> >>>
> >>> > From: Michael S. Tsirkin <[email protected]>
> >>> >
> >>> > For small packets we can simplify xmit processing
> >>> > by linearizing buffers with the header:
> >>> > most packets seem to have enough head room
> >>> > we can use for this purpose.
> >>> > Since existing hypervisors require that header
> >>> > is the first s/g element, we need a feature bit
> >>> > for this.
> >>> >
> >>> > Signed-off-by: Michael S. Tsirkin <[email protected]>
> >>> > Signed-off-by: Rusty Russell <[email protected]>
> >>>
> >>> I really think this has to wait until the next merge window, sorry.
> >>>
> >>> Please resubmit this when I open net-next back up, thanks.
> >>
> >> I assumed since -rc1 is out net-next is already open?
> >
> > -rc1 being released never makes net-next open. Instead, I explicitly
> > open it up at some point in time after -rc1 when I feel that things
> > have settled down enough.
> >
> > And when that happens, I announce so here.
> >
> > So you have to follow my announcements here on netdev to know
> > when net-next is actually open.
>
> Thanks for letting me know. I'm sure that works well for others, but I
> can't follow the mailing lists of every maintainer I deal with.
>
> Fortunately, you're the paragon for acking applied patches, so if I hit
> this failure mode again I will know.
>
> Cheers,
> Rusty.

In case you missed this, net-next opened Fri, 19 Jul 2013.

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MST