Re: [PATCH V2 4/6] vhost_net: determine whether or not to use zerocopy at one time
On 08/31/2013 02:35 AM, Sergei Shtylyov wrote:
> Hello.
>
> On 08/30/2013 08:29 AM, Jason Wang wrote:
>
>> Currently, even if the packet length is smaller than
>> VHOST_GOODCOPY_LEN, if
>> upend_idx != done_idx we still set zcopy_used to true and rollback
>> this choice
>> later. This could be avoided by determine zerocopy once by checking all
>> conditions at one time before.
>
>> Signed-off-by: Jason Wang
>> ---
>> drivers/vhost/net.c | 46
>> +++---
>> 1 files changed, 19 insertions(+), 27 deletions(-)
>
>> diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
>> index 8a6dd0d..ff60c2a 100644
>> --- a/drivers/vhost/net.c
>> +++ b/drivers/vhost/net.c
>> @@ -404,43 +404,35 @@ static void handle_tx(struct vhost_net *net)
>> iov_length(nvq->hdr, s), hdr_size);
>> break;
>> }
>> -zcopy_used = zcopy && (len >= VHOST_GOODCOPY_LEN ||
>> - nvq->upend_idx != nvq->done_idx);
>> +
>> +zcopy_used = zcopy && len >= VHOST_GOODCOPY_LEN
>> +&& (nvq->upend_idx + 1) % UIO_MAXIOV != nvq->done_idx
>> +&& vhost_net_tx_select_zcopy(net);
>
>Could you leave && on a first of two lines, matching the previous
> style?
>
ok.
>>
>> /* use msg_control to pass vhost zerocopy ubuf info to skb */
>> if (zcopy_used) {
>> +struct ubuf_info *ubuf;
>> +ubuf = nvq->ubuf_info + nvq->upend_idx;
>> +
>> vq->heads[nvq->upend_idx].id = head;
> [...]
>> +vq->heads[nvq->upend_idx].len = VHOST_DMA_IN_PROGRESS;
>> +ubuf->callback = vhost_zerocopy_callback;
>> +ubuf->ctx = nvq->ubufs;
>> +ubuf->desc = nvq->upend_idx;
>> +msg.msg_control = ubuf;
>> +msg.msg_controllen = sizeof(ubuf);
>
>'sizeof(ubuf)' where 'ubuf' is a pointer? Are you sure it shouldn't
> be 'sizeof(*ubuf)'?
Yes, pointer is sufficiet. Vhost allocate an arrays of ubuf and
tun/macvtap just need a reference of it.
>
> WBR, Sergei
>
> --
> To unsubscribe from this list: send the line "unsubscribe kvm" in
> the body of a message to majord...@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH V2 4/6] vhost_net: determine whether or not to use zerocopy at one time
On 08/31/2013 02:35 AM, Sergei Shtylyov wrote:
Hello.
On 08/30/2013 08:29 AM, Jason Wang wrote:
Currently, even if the packet length is smaller than
VHOST_GOODCOPY_LEN, if
upend_idx != done_idx we still set zcopy_used to true and rollback
this choice
later. This could be avoided by determine zerocopy once by checking all
conditions at one time before.
Signed-off-by: Jason Wang jasow...@redhat.com
---
drivers/vhost/net.c | 46
+++---
1 files changed, 19 insertions(+), 27 deletions(-)
diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index 8a6dd0d..ff60c2a 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -404,43 +404,35 @@ static void handle_tx(struct vhost_net *net)
iov_length(nvq-hdr, s), hdr_size);
break;
}
-zcopy_used = zcopy (len = VHOST_GOODCOPY_LEN ||
- nvq-upend_idx != nvq-done_idx);
+
+zcopy_used = zcopy len = VHOST_GOODCOPY_LEN
+ (nvq-upend_idx + 1) % UIO_MAXIOV != nvq-done_idx
+ vhost_net_tx_select_zcopy(net);
Could you leave on a first of two lines, matching the previous
style?
ok.
/* use msg_control to pass vhost zerocopy ubuf info to skb */
if (zcopy_used) {
+struct ubuf_info *ubuf;
+ubuf = nvq-ubuf_info + nvq-upend_idx;
+
vq-heads[nvq-upend_idx].id = head;
[...]
+vq-heads[nvq-upend_idx].len = VHOST_DMA_IN_PROGRESS;
+ubuf-callback = vhost_zerocopy_callback;
+ubuf-ctx = nvq-ubufs;
+ubuf-desc = nvq-upend_idx;
+msg.msg_control = ubuf;
+msg.msg_controllen = sizeof(ubuf);
'sizeof(ubuf)' where 'ubuf' is a pointer? Are you sure it shouldn't
be 'sizeof(*ubuf)'?
Yes, pointer is sufficiet. Vhost allocate an arrays of ubuf and
tun/macvtap just need a reference of it.
WBR, Sergei
--
To unsubscribe from this list: send the line unsubscribe kvm in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
--
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH V2 4/6] vhost_net: determine whether or not to use zerocopy at one time
Hello.
On 08/30/2013 08:29 AM, Jason Wang wrote:
Currently, even if the packet length is smaller than VHOST_GOODCOPY_LEN, if
upend_idx != done_idx we still set zcopy_used to true and rollback this choice
later. This could be avoided by determine zerocopy once by checking all
conditions at one time before.
Signed-off-by: Jason Wang
---
drivers/vhost/net.c | 46 +++---
1 files changed, 19 insertions(+), 27 deletions(-)
diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index 8a6dd0d..ff60c2a 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -404,43 +404,35 @@ static void handle_tx(struct vhost_net *net)
iov_length(nvq->hdr, s), hdr_size);
break;
}
- zcopy_used = zcopy && (len >= VHOST_GOODCOPY_LEN ||
- nvq->upend_idx != nvq->done_idx);
+
+ zcopy_used = zcopy && len >= VHOST_GOODCOPY_LEN
+ && (nvq->upend_idx + 1) % UIO_MAXIOV != nvq->done_idx
+ && vhost_net_tx_select_zcopy(net);
Could you leave && on a first of two lines, matching the previous style?
/* use msg_control to pass vhost zerocopy ubuf info to skb */
if (zcopy_used) {
+ struct ubuf_info *ubuf;
+ ubuf = nvq->ubuf_info + nvq->upend_idx;
+
vq->heads[nvq->upend_idx].id = head;
[...]
+ vq->heads[nvq->upend_idx].len = VHOST_DMA_IN_PROGRESS;
+ ubuf->callback = vhost_zerocopy_callback;
+ ubuf->ctx = nvq->ubufs;
+ ubuf->desc = nvq->upend_idx;
+ msg.msg_control = ubuf;
+ msg.msg_controllen = sizeof(ubuf);
'sizeof(ubuf)' where 'ubuf' is a pointer? Are you sure it shouldn't be
'sizeof(*ubuf)'?
WBR, Sergei
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH V2 4/6] vhost_net: determine whether or not to use zerocopy at one time
Hello.
On 08/30/2013 08:29 AM, Jason Wang wrote:
Currently, even if the packet length is smaller than VHOST_GOODCOPY_LEN, if
upend_idx != done_idx we still set zcopy_used to true and rollback this choice
later. This could be avoided by determine zerocopy once by checking all
conditions at one time before.
Signed-off-by: Jason Wang jasow...@redhat.com
---
drivers/vhost/net.c | 46 +++---
1 files changed, 19 insertions(+), 27 deletions(-)
diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index 8a6dd0d..ff60c2a 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -404,43 +404,35 @@ static void handle_tx(struct vhost_net *net)
iov_length(nvq-hdr, s), hdr_size);
break;
}
- zcopy_used = zcopy (len = VHOST_GOODCOPY_LEN ||
- nvq-upend_idx != nvq-done_idx);
+
+ zcopy_used = zcopy len = VHOST_GOODCOPY_LEN
+(nvq-upend_idx + 1) % UIO_MAXIOV != nvq-done_idx
+vhost_net_tx_select_zcopy(net);
Could you leave on a first of two lines, matching the previous style?
/* use msg_control to pass vhost zerocopy ubuf info to skb */
if (zcopy_used) {
+ struct ubuf_info *ubuf;
+ ubuf = nvq-ubuf_info + nvq-upend_idx;
+
vq-heads[nvq-upend_idx].id = head;
[...]
+ vq-heads[nvq-upend_idx].len = VHOST_DMA_IN_PROGRESS;
+ ubuf-callback = vhost_zerocopy_callback;
+ ubuf-ctx = nvq-ubufs;
+ ubuf-desc = nvq-upend_idx;
+ msg.msg_control = ubuf;
+ msg.msg_controllen = sizeof(ubuf);
'sizeof(ubuf)' where 'ubuf' is a pointer? Are you sure it shouldn't be
'sizeof(*ubuf)'?
WBR, Sergei
--
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
