| Message ID | 1377836962-49780-5-git-send-email-jasowang@redhat.com |
|---|---|
| State | Superseded, archived |
| Delegated to: | David Miller |
| Headers | show |
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 <jasowang@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 netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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 <jasowang@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 majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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); /* 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; - if (!vhost_net_tx_select_zcopy(net) || - len < VHOST_GOODCOPY_LEN) { - /* copy don't need to wait for DMA done */ - vq->heads[nvq->upend_idx].len = - VHOST_DMA_DONE_LEN; - msg.msg_control = NULL; - msg.msg_controllen = 0; - ubufs = NULL; - } else { - struct ubuf_info *ubuf; - ubuf = nvq->ubuf_info + nvq->upend_idx; - - 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); - ubufs = nvq->ubufs; - kref_get(&ubufs->kref); - } + 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); + ubufs = nvq->ubufs; + kref_get(&ubufs->kref); nvq->upend_idx = (nvq->upend_idx + 1) % UIO_MAXIOV; - } else + } else { msg.msg_control = NULL; + ubufs = NULL; + } /* TODO: Check specific error and bomb out unless ENOBUFS? */ err = sock->ops->sendmsg(NULL, sock, &msg, len); if (unlikely(err < 0)) { if (zcopy_used) { - if (ubufs) - vhost_net_ubuf_put(ubufs); + vhost_net_ubuf_put(ubufs); nvq->upend_idx = ((unsigned)nvq->upend_idx - 1) % UIO_MAXIOV; }
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 <jasowang@redhat.com> --- drivers/vhost/net.c | 46 +++++++++++++++++++--------------------------- 1 files changed, 19 insertions(+), 27 deletions(-)