| Message ID | AS2P194MB21702C53FEFDC2F8283B5A789AC22@AS2P194MB2170.EURP194.PROD.OUTLOOK.COM (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | vsock: avoid queuing on workqueue if possible | expand |
On Fri, Jun 14, 2024 at 03:55:42PM GMT, Luigi Leonardi wrote: >From: Marco Pinna <marco.pinn95@gmail.com> > >This is a preliminary patch to introduce an optimization to >the enqueue system. > >All the code used to enqueue a packet into the virtqueue >is removed from virtio_transport_send_pkt_work() >and moved to the new virtio_transport_send_skb() function. > >Co-developed-by: Luigi Leonardi <luigi.leonardi@outlook.com> >Signed-off-by: Luigi Leonardi <luigi.leonardi@outlook.com> >Signed-off-by: Marco Pinna <marco.pinn95@gmail.com> >--- > net/vmw_vsock/virtio_transport.c | 134 +++++++++++++++++-------------- > 1 file changed, 74 insertions(+), 60 deletions(-) > >diff --git a/net/vmw_vsock/virtio_transport.c b/net/vmw_vsock/virtio_transport.c >index 43d405298857..c930235ecaec 100644 >--- a/net/vmw_vsock/virtio_transport.c >+++ b/net/vmw_vsock/virtio_transport.c >@@ -94,6 +94,78 @@ static u32 virtio_transport_get_local_cid(void) > return ret; > } > >+/* Caller need to hold vsock->tx_lock on vq */ >+static int virtio_transport_send_skb(struct sk_buff *skb, struct virtqueue *vq, >+ struct virtio_vsock *vsock, bool *restart_rx) >+{ >+ int ret, in_sg = 0, out_sg = 0; >+ struct scatterlist **sgs; >+ bool reply; >+ >+ reply = virtio_vsock_skb_reply(skb); >+ sgs = vsock->out_sgs; >+ sg_init_one(sgs[out_sg], virtio_vsock_hdr(skb), >+ sizeof(*virtio_vsock_hdr(skb))); >+ out_sg++; >+ >+ if (!skb_is_nonlinear(skb)) { >+ if (skb->len > 0) { >+ sg_init_one(sgs[out_sg], skb->data, skb->len); >+ out_sg++; >+ } >+ } else { >+ struct skb_shared_info *si; >+ int i; >+ >+ /* If skb is nonlinear, then its buffer must contain >+ * only header and nothing more. Data is stored in >+ * the fragged part. >+ */ >+ WARN_ON_ONCE(skb_headroom(skb) != sizeof(*virtio_vsock_hdr(skb))); >+ >+ si = skb_shinfo(skb); >+ >+ for (i = 0; i < si->nr_frags; i++) { >+ skb_frag_t *skb_frag = &si->frags[i]; >+ void *va; >+ >+ /* We will use 'page_to_virt()' for the userspace page >+ * here, because virtio or dma-mapping layers will call >+ * 'virt_to_phys()' later to fill the buffer descriptor. >+ * We don't touch memory at "virtual" address of >this page. >+ */ >+ va = page_to_virt(skb_frag_page(skb_frag)); >+ sg_init_one(sgs[out_sg], >+ va + skb_frag_off(skb_frag), >+ skb_frag_size(skb_frag)); >+ out_sg++; >+ } >+ } >+ >+ ret = virtqueue_add_sgs(vq, sgs, out_sg, in_sg, skb, GFP_KERNEL); >+ /* Usually this means that there is no more space available in >+ * the vq >+ */ >+ if (ret < 0) >+ goto out; We use the `out` label just here, so what about remove it since we just return ret? I mean: if (ret < 0) return ret; ... >+ >+ virtio_transport_deliver_tap_pkt(skb); >+ >+ if (reply) { >+ struct virtqueue *rx_vq = vsock->vqs[VSOCK_VQ_RX]; >+ int val; >+ >+ val = atomic_dec_return(&vsock->queued_replies); >+ >+ /* Do we now have resources to resume rx processing? */ >+ if (val + 1 == virtqueue_get_vring_size(rx_vq)) >+ *restart_rx = true; >+ } >+ return 0; } >+out: >+ return ret; >+} >+ > static void > virtio_transport_send_pkt_work(struct work_struct *work) > { >@@ -111,77 +183,19 @@ virtio_transport_send_pkt_work(struct work_struct *work) > vq = vsock->vqs[VSOCK_VQ_TX]; > > for (;;) { >- int ret, in_sg = 0, out_sg = 0; >- struct scatterlist **sgs; > struct sk_buff *skb; >- bool reply; >+ int ret; > > skb = virtio_vsock_skb_dequeue(&vsock->send_pkt_queue); > if (!skb) > break; > >- reply = virtio_vsock_skb_reply(skb); >- sgs = vsock->out_sgs; >- sg_init_one(sgs[out_sg], virtio_vsock_hdr(skb), >- sizeof(*virtio_vsock_hdr(skb))); >- out_sg++; >- >- if (!skb_is_nonlinear(skb)) { >- if (skb->len > 0) { >- sg_init_one(sgs[out_sg], skb->data, skb->len); >- out_sg++; >- } >- } else { >- struct skb_shared_info *si; >- int i; >+ ret = virtio_transport_send_skb(skb, vq, vsock, &restart_rx); > nit: I'd remove this new line here. >- /* If skb is nonlinear, then its buffer must contain >- * only header and nothing more. Data is stored in >- * the fragged part. >- */ >- WARN_ON_ONCE(skb_headroom(skb) != sizeof(*virtio_vsock_hdr(skb))); >- >- si = skb_shinfo(skb); >- >- for (i = 0; i < si->nr_frags; i++) { >- skb_frag_t *skb_frag = &si->frags[i]; >- void *va; >- >- /* We will use 'page_to_virt()' for the userspace page >- * here, because virtio or dma-mapping layers will call >- * 'virt_to_phys()' later to fill the buffer descriptor. >- * We don't touch memory at "virtual" address of this page. >- */ >- va = page_to_virt(skb_frag_page(skb_frag)); >- sg_init_one(sgs[out_sg], >- va + skb_frag_off(skb_frag), >- skb_frag_size(skb_frag)); >- out_sg++; >- } >- } >- >- ret = virtqueue_add_sgs(vq, sgs, out_sg, in_sg, skb, >GFP_KERNEL); >- /* Usually this means that there is no more space >available in >- * the vq >- */ > if (ret < 0) { > virtio_vsock_skb_queue_head(&vsock->send_pkt_queue, skb); > break; > } >- >- virtio_transport_deliver_tap_pkt(skb); >- >- if (reply) { >- struct virtqueue *rx_vq = vsock->vqs[VSOCK_VQ_RX]; >- int val; >- >- val = atomic_dec_return(&vsock->queued_replies); >- >- /* Do we now have resources to resume rx processing? */ >- if (val + 1 == virtqueue_get_vring_size(rx_vq)) >- restart_rx = true; >- } >- nit: maybe I'd move the empty line here. Our usual style is: ret = foo(); if (ret < 0) { //error handling } next_stuff... Thanks, Stefano > added = true; > } > >-- >2.45.2 >
diff --git a/net/vmw_vsock/virtio_transport.c b/net/vmw_vsock/virtio_transport.c index 43d405298857..c930235ecaec 100644 --- a/net/vmw_vsock/virtio_transport.c +++ b/net/vmw_vsock/virtio_transport.c @@ -94,6 +94,78 @@ static u32 virtio_transport_get_local_cid(void) return ret; } +/* Caller need to hold vsock->tx_lock on vq */ +static int virtio_transport_send_skb(struct sk_buff *skb, struct virtqueue *vq, + struct virtio_vsock *vsock, bool *restart_rx) +{ + int ret, in_sg = 0, out_sg = 0; + struct scatterlist **sgs; + bool reply; + + reply = virtio_vsock_skb_reply(skb); + sgs = vsock->out_sgs; + sg_init_one(sgs[out_sg], virtio_vsock_hdr(skb), + sizeof(*virtio_vsock_hdr(skb))); + out_sg++; + + if (!skb_is_nonlinear(skb)) { + if (skb->len > 0) { + sg_init_one(sgs[out_sg], skb->data, skb->len); + out_sg++; + } + } else { + struct skb_shared_info *si; + int i; + + /* If skb is nonlinear, then its buffer must contain + * only header and nothing more. Data is stored in + * the fragged part. + */ + WARN_ON_ONCE(skb_headroom(skb) != sizeof(*virtio_vsock_hdr(skb))); + + si = skb_shinfo(skb); + + for (i = 0; i < si->nr_frags; i++) { + skb_frag_t *skb_frag = &si->frags[i]; + void *va; + + /* We will use 'page_to_virt()' for the userspace page + * here, because virtio or dma-mapping layers will call + * 'virt_to_phys()' later to fill the buffer descriptor. + * We don't touch memory at "virtual" address of this page. + */ + va = page_to_virt(skb_frag_page(skb_frag)); + sg_init_one(sgs[out_sg], + va + skb_frag_off(skb_frag), + skb_frag_size(skb_frag)); + out_sg++; + } + } + + ret = virtqueue_add_sgs(vq, sgs, out_sg, in_sg, skb, GFP_KERNEL); + /* Usually this means that there is no more space available in + * the vq + */ + if (ret < 0) + goto out; + + virtio_transport_deliver_tap_pkt(skb); + + if (reply) { + struct virtqueue *rx_vq = vsock->vqs[VSOCK_VQ_RX]; + int val; + + val = atomic_dec_return(&vsock->queued_replies); + + /* Do we now have resources to resume rx processing? */ + if (val + 1 == virtqueue_get_vring_size(rx_vq)) + *restart_rx = true; + } + +out: + return ret; +} + static void virtio_transport_send_pkt_work(struct work_struct *work) { @@ -111,77 +183,19 @@ virtio_transport_send_pkt_work(struct work_struct *work) vq = vsock->vqs[VSOCK_VQ_TX]; for (;;) { - int ret, in_sg = 0, out_sg = 0; - struct scatterlist **sgs; struct sk_buff *skb; - bool reply; + int ret; skb = virtio_vsock_skb_dequeue(&vsock->send_pkt_queue); if (!skb) break; - reply = virtio_vsock_skb_reply(skb); - sgs = vsock->out_sgs; - sg_init_one(sgs[out_sg], virtio_vsock_hdr(skb), - sizeof(*virtio_vsock_hdr(skb))); - out_sg++; - - if (!skb_is_nonlinear(skb)) { - if (skb->len > 0) { - sg_init_one(sgs[out_sg], skb->data, skb->len); - out_sg++; - } - } else { - struct skb_shared_info *si; - int i; + ret = virtio_transport_send_skb(skb, vq, vsock, &restart_rx); - /* If skb is nonlinear, then its buffer must contain - * only header and nothing more. Data is stored in - * the fragged part. - */ - WARN_ON_ONCE(skb_headroom(skb) != sizeof(*virtio_vsock_hdr(skb))); - - si = skb_shinfo(skb); - - for (i = 0; i < si->nr_frags; i++) { - skb_frag_t *skb_frag = &si->frags[i]; - void *va; - - /* We will use 'page_to_virt()' for the userspace page - * here, because virtio or dma-mapping layers will call - * 'virt_to_phys()' later to fill the buffer descriptor. - * We don't touch memory at "virtual" address of this page. - */ - va = page_to_virt(skb_frag_page(skb_frag)); - sg_init_one(sgs[out_sg], - va + skb_frag_off(skb_frag), - skb_frag_size(skb_frag)); - out_sg++; - } - } - - ret = virtqueue_add_sgs(vq, sgs, out_sg, in_sg, skb, GFP_KERNEL); - /* Usually this means that there is no more space available in - * the vq - */ if (ret < 0) { virtio_vsock_skb_queue_head(&vsock->send_pkt_queue, skb); break; } - - virtio_transport_deliver_tap_pkt(skb); - - if (reply) { - struct virtqueue *rx_vq = vsock->vqs[VSOCK_VQ_RX]; - int val; - - val = atomic_dec_return(&vsock->queued_replies); - - /* Do we now have resources to resume rx processing? */ - if (val + 1 == virtqueue_get_vring_size(rx_vq)) - restart_rx = true; - } - added = true; }