| Message ID | 1360944010-15336-8-git-send-email-wei.liu2@citrix.com |
|---|---|
| State | Not Applicable, archived |
| Delegated to: | David Miller |
| Headers | show |
On Fri, Feb 15, 2013 at 04:00:08PM +0000, Wei Liu wrote: > Netback and netfront only use one event channel to do tx / rx notification. > This may cause unnecessary wake-up of process routines. This patch adds a new > feature called feautre-split-event-channel to netback, enabling it to handle 'feature', not 'feautre'. In the code it looks to also be plural: feature-split-event-channels and there is also event-channel-tx and event-channel-rx attribute. You need to also send an patch to Xen hypervisor tree for this new XenBus attributes and provide the appropiate syntax. > Tx and Rx event separately. > > Netback will use tx_irq to notify guest for tx completion, rx_irq for rx > notification. > > If frontend doesn't support this feature, tx_irq = rx_irq. > > Signed-off-by: Wei Liu <wei.liu2@citrix.com> > --- > drivers/net/xen-netback/common.h | 10 +++-- > drivers/net/xen-netback/interface.c | 78 ++++++++++++++++++++++++++++------- > drivers/net/xen-netback/netback.c | 7 ++-- > drivers/net/xen-netback/xenbus.c | 44 ++++++++++++++++---- > 4 files changed, 109 insertions(+), 30 deletions(-) > > diff --git a/drivers/net/xen-netback/common.h b/drivers/net/xen-netback/common.h > index f541ba9..cc2a9f0 100644 > --- a/drivers/net/xen-netback/common.h > +++ b/drivers/net/xen-netback/common.h > @@ -63,8 +63,11 @@ struct xenvif { > > u8 fe_dev_addr[6]; > > - /* Physical parameters of the comms window. */ > - unsigned int irq; > + /* Physical parameters of the comms window. > + * When feature-split-event-channels = 0, tx_irq = rx_irq. > + */ > + unsigned int tx_irq; > + unsigned int rx_irq; > > /* List of frontends to notify after a batch of frames sent. */ > struct list_head notify_list; > @@ -122,10 +125,11 @@ struct xenvif *xenvif_alloc(struct device *parent, > domid_t domid, > unsigned int handle); > > +/* When feature-split-event-channels == 0, tx_evtchn == rx_evtchn */ > int xenvif_connect(struct xenvif *vif, > unsigned long *tx_ring_ref, unsigned int tx_ring_order, > unsigned long *rx_ring_ref, unsigned int rx_ring_order, > - unsigned int evtchn); > + unsigned int tx_evtchn, unsigned int rx_evtchn); > void xenvif_disconnect(struct xenvif *vif); > > void xenvif_get(struct xenvif *vif); > diff --git a/drivers/net/xen-netback/interface.c b/drivers/net/xen-netback/interface.c > index fa4d46d..c9ebe21 100644 > --- a/drivers/net/xen-netback/interface.c > +++ b/drivers/net/xen-netback/interface.c > @@ -60,7 +60,8 @@ static int xenvif_rx_schedulable(struct xenvif *vif) > return xenvif_schedulable(vif) && !xen_netbk_rx_ring_full(vif); > } > > -static irqreturn_t xenvif_interrupt(int irq, void *dev_id) > +/* Tx interrupt handler used when feature-split-event-channels == 1 */ > +static irqreturn_t xenvif_tx_interrupt(int tx_irq, void *dev_id) > { > struct xenvif *vif = dev_id; > > @@ -69,12 +70,31 @@ static irqreturn_t xenvif_interrupt(int irq, void *dev_id) > > xen_netbk_schedule_xenvif(vif); > > + return IRQ_HANDLED; > +} > + > +/* Rx interrupt handler used when feature-split-event-channels == 1 */ > +static irqreturn_t xenvif_rx_interrupt(int rx_irq, void *dev_id) > +{ > + struct xenvif *vif = dev_id; > + > + if (vif->netbk == NULL) > + return IRQ_NONE; > + > if (xenvif_rx_schedulable(vif)) > netif_wake_queue(vif->dev); > > return IRQ_HANDLED; > } > > +/* Used when feature-split-event-channels == 0 */ > +static irqreturn_t xenvif_interrupt(int irq, void *dev_id) > +{ > + xenvif_tx_interrupt(irq, dev_id); > + xenvif_rx_interrupt(irq, dev_id); > + return IRQ_HANDLED; > +} > + > static int xenvif_start_xmit(struct sk_buff *skb, struct net_device *dev) > { > struct xenvif *vif = netdev_priv(dev); > @@ -125,13 +145,15 @@ static struct net_device_stats *xenvif_get_stats(struct net_device *dev) > static void xenvif_up(struct xenvif *vif) > { > xen_netbk_add_xenvif(vif); > - enable_irq(vif->irq); > + enable_irq(vif->tx_irq); > + enable_irq(vif->rx_irq); > xen_netbk_check_rx_xenvif(vif); > } > > static void xenvif_down(struct xenvif *vif) > { > - disable_irq(vif->irq); > + disable_irq(vif->tx_irq); > + disable_irq(vif->rx_irq); > del_timer_sync(&vif->credit_timeout); > xen_netbk_deschedule_xenvif(vif); > xen_netbk_remove_xenvif(vif); > @@ -308,7 +330,7 @@ struct xenvif *xenvif_alloc(struct device *parent, domid_t domid, > int xenvif_connect(struct xenvif *vif, > unsigned long *tx_ring_ref, unsigned int tx_ring_ref_count, > unsigned long *rx_ring_ref, unsigned int rx_ring_ref_count, > - unsigned int evtchn) > + unsigned int tx_evtchn, unsigned int rx_evtchn) > { > int err = -ENOMEM; > void *addr; > @@ -317,7 +339,7 @@ int xenvif_connect(struct xenvif *vif, > int tmp[NETBK_MAX_RING_PAGES], i; > > /* Already connected through? */ > - if (vif->irq) > + if (vif->tx_irq) > return 0; > > __module_get(THIS_MODULE); > @@ -347,13 +369,32 @@ int xenvif_connect(struct xenvif *vif, > BACK_RING_INIT(&vif->rx, rxs, PAGE_SIZE * rx_ring_ref_count); > vif->nr_rx_handles = rx_ring_ref_count; > > - err = bind_interdomain_evtchn_to_irqhandler( > - vif->domid, evtchn, xenvif_interrupt, 0, > - vif->dev->name, vif); > - if (err < 0) > - goto err_rx_unmap; > - vif->irq = err; > - disable_irq(vif->irq); > + if (tx_evtchn == rx_evtchn) { /* feature-split-event-channels == 0 */ > + err = bind_interdomain_evtchn_to_irqhandler( > + vif->domid, tx_evtchn, xenvif_interrupt, 0, > + vif->dev->name, vif); > + if (err < 0) > + goto err_rx_unmap; > + vif->tx_irq = vif->rx_irq = err; > + disable_irq(vif->tx_irq); > + disable_irq(vif->rx_irq); > + } else { /* feature-split-event-channels == 1 */ > + err = bind_interdomain_evtchn_to_irqhandler( > + vif->domid, tx_evtchn, xenvif_tx_interrupt, 0, > + vif->dev->name, vif); > + if (err < 0) > + goto err_rx_unmap; > + vif->tx_irq = err; > + disable_irq(vif->tx_irq); > + > + err = bind_interdomain_evtchn_to_irqhandler( > + vif->domid, rx_evtchn, xenvif_rx_interrupt, 0, > + vif->dev->name, vif); > + if (err < 0) > + goto err_tx_unbind; > + vif->rx_irq = err; > + disable_irq(vif->rx_irq); > + } > > xenvif_get(vif); > > @@ -367,6 +408,10 @@ int xenvif_connect(struct xenvif *vif, > rtnl_unlock(); > > return 0; > + > +err_tx_unbind: > + unbind_from_irqhandler(vif->tx_irq, vif); > + vif->tx_irq = 0; > err_rx_unmap: > xen_netbk_unmap_frontend_rings(vif, (void *)vif->rx.sring); > vif->nr_rx_handles = 0; > @@ -406,8 +451,13 @@ void xenvif_disconnect(struct xenvif *vif) > atomic_dec(&vif->refcnt); > wait_event(vif->waiting_to_free, atomic_read(&vif->refcnt) == 0); > > - if (vif->irq) { > - unbind_from_irqhandler(vif->irq, vif); > + if (vif->tx_irq) { > + if (vif->tx_irq == vif->rx_irq) > + unbind_from_irqhandler(vif->tx_irq, vif); > + else { > + unbind_from_irqhandler(vif->tx_irq, vif); > + unbind_from_irqhandler(vif->rx_irq, vif); > + } > need_module_put = 1; > } > > diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c > index 644c760..5ac8c35 100644 > --- a/drivers/net/xen-netback/netback.c > +++ b/drivers/net/xen-netback/netback.c > @@ -639,7 +639,7 @@ static void xen_netbk_rx_action(struct xen_netbk *netbk) > { > struct xenvif *vif = NULL, *tmp; > s8 status; > - u16 irq, flags; > + u16 flags; > struct xen_netif_rx_response *resp; > struct sk_buff_head rxq; > struct sk_buff *skb; > @@ -750,7 +750,6 @@ static void xen_netbk_rx_action(struct xen_netbk *netbk) > sco->meta_slots_used); > > RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&vif->rx, ret); > - irq = vif->irq; > if (ret && list_empty(&vif->notify_list)) > list_add_tail(&vif->notify_list, ¬ify); > > @@ -762,7 +761,7 @@ static void xen_netbk_rx_action(struct xen_netbk *netbk) > } > > list_for_each_entry_safe(vif, tmp, ¬ify, notify_list) { > - notify_remote_via_irq(vif->irq); > + notify_remote_via_irq(vif->rx_irq); > list_del_init(&vif->notify_list); > } > > @@ -1595,7 +1594,7 @@ static void make_tx_response(struct xenvif *vif, > vif->tx.rsp_prod_pvt = ++i; > RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&vif->tx, notify); > if (notify) > - notify_remote_via_irq(vif->irq); > + notify_remote_via_irq(vif->tx_irq); > } > > static struct xen_netif_rx_response *make_rx_response(struct xenvif *vif, > diff --git a/drivers/net/xen-netback/xenbus.c b/drivers/net/xen-netback/xenbus.c > index 1791807..6822d89 100644 > --- a/drivers/net/xen-netback/xenbus.c > +++ b/drivers/net/xen-netback/xenbus.c > @@ -141,6 +141,15 @@ static int netback_probe(struct xenbus_device *dev, > goto abort_transaction; > } > > + /* Split event channels support */ > + err = xenbus_printf(xbt, dev->nodename, > + "feature-split-event-channels", > + "%u", 1); > + if (err) { > + message = "writing feature-split-event-channels"; > + goto abort_transaction; > + } I wouldn't abort b/c of it. Just continue on without using this. > + > err = xenbus_transaction_end(xbt, 0); > } while (err == -EAGAIN); > > @@ -419,7 +428,7 @@ static int connect_rings(struct backend_info *be) > { > struct xenvif *vif = be->vif; > struct xenbus_device *dev = be->dev; > - unsigned int evtchn, rx_copy; > + unsigned int tx_evtchn, rx_evtchn, rx_copy; > int err; > int val; > unsigned long tx_ring_ref[NETBK_MAX_RING_PAGES]; > @@ -428,12 +437,22 @@ static int connect_rings(struct backend_info *be) > unsigned int rx_ring_order; > > err = xenbus_gather(XBT_NIL, dev->otherend, > - "event-channel", "%u", &evtchn, NULL); > + "event-channel", "%u", &tx_evtchn, NULL); > if (err) { > - xenbus_dev_fatal(dev, err, > - "reading %s/event-channel", > - dev->otherend); > - return err; > + /* try split event channels */ > + err = xenbus_gather(XBT_NIL, dev->otherend, > + "event-channel-tx", "%u", &tx_evtchn, > + "event-channel-rx", "%u", &rx_evtchn, > + NULL); > + if (err) { > + xenbus_dev_fatal(dev, err, > + "reading %s/event-channel(-tx/rx)", > + dev->otherend); > + return err; > + } > + } else { /* frontend doesn't support split event channels */ > + rx_evtchn = tx_evtchn; > + dev_info(&dev->dev, "single event channel\n"); > } > > err = xenbus_scanf(XBT_NIL, dev->otherend, "tx-ring-order", "%u", > @@ -568,12 +587,19 @@ static int connect_rings(struct backend_info *be) > /* Map the shared frame, irq etc. */ > err = xenvif_connect(vif, tx_ring_ref, (1U << tx_ring_order), > rx_ring_ref, (1U << rx_ring_order), > - evtchn); > + tx_evtchn, rx_evtchn); > if (err) { > /* construct 1 2 3 / 4 5 6 */ > int i; > char txs[3 * (1U << MODPARM_netback_max_tx_ring_page_order)]; > char rxs[3 * (1U << MODPARM_netback_max_rx_ring_page_order)]; > + char evtchns[20]; > + > + if (tx_evtchn == rx_evtchn) > + snprintf(evtchns, sizeof(evtchns)-1, "%u", tx_evtchn); > + else > + snprintf(evtchns, sizeof(evtchns)-1, "%u/%u", > + tx_evtchn, rx_evtchn); > > txs[0] = rxs[0] = 0; > > @@ -586,8 +612,8 @@ static int connect_rings(struct backend_info *be) > " %lu", rx_ring_ref[i]); > > xenbus_dev_fatal(dev, err, > - "mapping shared-frames%s /%s port %u", > - txs, rxs, evtchn); > + "mapping shared-frames%s /%s port %s", > + txs, rxs, evtchns); > return err; > } > return 0; > -- > 1.7.10.4 > -- 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/net/xen-netback/common.h b/drivers/net/xen-netback/common.h index f541ba9..cc2a9f0 100644 --- a/drivers/net/xen-netback/common.h +++ b/drivers/net/xen-netback/common.h @@ -63,8 +63,11 @@ struct xenvif { u8 fe_dev_addr[6]; - /* Physical parameters of the comms window. */ - unsigned int irq; + /* Physical parameters of the comms window. + * When feature-split-event-channels = 0, tx_irq = rx_irq. + */ + unsigned int tx_irq; + unsigned int rx_irq; /* List of frontends to notify after a batch of frames sent. */ struct list_head notify_list; @@ -122,10 +125,11 @@ struct xenvif *xenvif_alloc(struct device *parent, domid_t domid, unsigned int handle); +/* When feature-split-event-channels == 0, tx_evtchn == rx_evtchn */ int xenvif_connect(struct xenvif *vif, unsigned long *tx_ring_ref, unsigned int tx_ring_order, unsigned long *rx_ring_ref, unsigned int rx_ring_order, - unsigned int evtchn); + unsigned int tx_evtchn, unsigned int rx_evtchn); void xenvif_disconnect(struct xenvif *vif); void xenvif_get(struct xenvif *vif); diff --git a/drivers/net/xen-netback/interface.c b/drivers/net/xen-netback/interface.c index fa4d46d..c9ebe21 100644 --- a/drivers/net/xen-netback/interface.c +++ b/drivers/net/xen-netback/interface.c @@ -60,7 +60,8 @@ static int xenvif_rx_schedulable(struct xenvif *vif) return xenvif_schedulable(vif) && !xen_netbk_rx_ring_full(vif); } -static irqreturn_t xenvif_interrupt(int irq, void *dev_id) +/* Tx interrupt handler used when feature-split-event-channels == 1 */ +static irqreturn_t xenvif_tx_interrupt(int tx_irq, void *dev_id) { struct xenvif *vif = dev_id; @@ -69,12 +70,31 @@ static irqreturn_t xenvif_interrupt(int irq, void *dev_id) xen_netbk_schedule_xenvif(vif); + return IRQ_HANDLED; +} + +/* Rx interrupt handler used when feature-split-event-channels == 1 */ +static irqreturn_t xenvif_rx_interrupt(int rx_irq, void *dev_id) +{ + struct xenvif *vif = dev_id; + + if (vif->netbk == NULL) + return IRQ_NONE; + if (xenvif_rx_schedulable(vif)) netif_wake_queue(vif->dev); return IRQ_HANDLED; } +/* Used when feature-split-event-channels == 0 */ +static irqreturn_t xenvif_interrupt(int irq, void *dev_id) +{ + xenvif_tx_interrupt(irq, dev_id); + xenvif_rx_interrupt(irq, dev_id); + return IRQ_HANDLED; +} + static int xenvif_start_xmit(struct sk_buff *skb, struct net_device *dev) { struct xenvif *vif = netdev_priv(dev); @@ -125,13 +145,15 @@ static struct net_device_stats *xenvif_get_stats(struct net_device *dev) static void xenvif_up(struct xenvif *vif) { xen_netbk_add_xenvif(vif); - enable_irq(vif->irq); + enable_irq(vif->tx_irq); + enable_irq(vif->rx_irq); xen_netbk_check_rx_xenvif(vif); } static void xenvif_down(struct xenvif *vif) { - disable_irq(vif->irq); + disable_irq(vif->tx_irq); + disable_irq(vif->rx_irq); del_timer_sync(&vif->credit_timeout); xen_netbk_deschedule_xenvif(vif); xen_netbk_remove_xenvif(vif); @@ -308,7 +330,7 @@ struct xenvif *xenvif_alloc(struct device *parent, domid_t domid, int xenvif_connect(struct xenvif *vif, unsigned long *tx_ring_ref, unsigned int tx_ring_ref_count, unsigned long *rx_ring_ref, unsigned int rx_ring_ref_count, - unsigned int evtchn) + unsigned int tx_evtchn, unsigned int rx_evtchn) { int err = -ENOMEM; void *addr; @@ -317,7 +339,7 @@ int xenvif_connect(struct xenvif *vif, int tmp[NETBK_MAX_RING_PAGES], i; /* Already connected through? */ - if (vif->irq) + if (vif->tx_irq) return 0; __module_get(THIS_MODULE); @@ -347,13 +369,32 @@ int xenvif_connect(struct xenvif *vif, BACK_RING_INIT(&vif->rx, rxs, PAGE_SIZE * rx_ring_ref_count); vif->nr_rx_handles = rx_ring_ref_count; - err = bind_interdomain_evtchn_to_irqhandler( - vif->domid, evtchn, xenvif_interrupt, 0, - vif->dev->name, vif); - if (err < 0) - goto err_rx_unmap; - vif->irq = err; - disable_irq(vif->irq); + if (tx_evtchn == rx_evtchn) { /* feature-split-event-channels == 0 */ + err = bind_interdomain_evtchn_to_irqhandler( + vif->domid, tx_evtchn, xenvif_interrupt, 0, + vif->dev->name, vif); + if (err < 0) + goto err_rx_unmap; + vif->tx_irq = vif->rx_irq = err; + disable_irq(vif->tx_irq); + disable_irq(vif->rx_irq); + } else { /* feature-split-event-channels == 1 */ + err = bind_interdomain_evtchn_to_irqhandler( + vif->domid, tx_evtchn, xenvif_tx_interrupt, 0, + vif->dev->name, vif); + if (err < 0) + goto err_rx_unmap; + vif->tx_irq = err; + disable_irq(vif->tx_irq); + + err = bind_interdomain_evtchn_to_irqhandler( + vif->domid, rx_evtchn, xenvif_rx_interrupt, 0, + vif->dev->name, vif); + if (err < 0) + goto err_tx_unbind; + vif->rx_irq = err; + disable_irq(vif->rx_irq); + } xenvif_get(vif); @@ -367,6 +408,10 @@ int xenvif_connect(struct xenvif *vif, rtnl_unlock(); return 0; + +err_tx_unbind: + unbind_from_irqhandler(vif->tx_irq, vif); + vif->tx_irq = 0; err_rx_unmap: xen_netbk_unmap_frontend_rings(vif, (void *)vif->rx.sring); vif->nr_rx_handles = 0; @@ -406,8 +451,13 @@ void xenvif_disconnect(struct xenvif *vif) atomic_dec(&vif->refcnt); wait_event(vif->waiting_to_free, atomic_read(&vif->refcnt) == 0); - if (vif->irq) { - unbind_from_irqhandler(vif->irq, vif); + if (vif->tx_irq) { + if (vif->tx_irq == vif->rx_irq) + unbind_from_irqhandler(vif->tx_irq, vif); + else { + unbind_from_irqhandler(vif->tx_irq, vif); + unbind_from_irqhandler(vif->rx_irq, vif); + } need_module_put = 1; } diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c index 644c760..5ac8c35 100644 --- a/drivers/net/xen-netback/netback.c +++ b/drivers/net/xen-netback/netback.c @@ -639,7 +639,7 @@ static void xen_netbk_rx_action(struct xen_netbk *netbk) { struct xenvif *vif = NULL, *tmp; s8 status; - u16 irq, flags; + u16 flags; struct xen_netif_rx_response *resp; struct sk_buff_head rxq; struct sk_buff *skb; @@ -750,7 +750,6 @@ static void xen_netbk_rx_action(struct xen_netbk *netbk) sco->meta_slots_used); RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&vif->rx, ret); - irq = vif->irq; if (ret && list_empty(&vif->notify_list)) list_add_tail(&vif->notify_list, ¬ify); @@ -762,7 +761,7 @@ static void xen_netbk_rx_action(struct xen_netbk *netbk) } list_for_each_entry_safe(vif, tmp, ¬ify, notify_list) { - notify_remote_via_irq(vif->irq); + notify_remote_via_irq(vif->rx_irq); list_del_init(&vif->notify_list); } @@ -1595,7 +1594,7 @@ static void make_tx_response(struct xenvif *vif, vif->tx.rsp_prod_pvt = ++i; RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&vif->tx, notify); if (notify) - notify_remote_via_irq(vif->irq); + notify_remote_via_irq(vif->tx_irq); } static struct xen_netif_rx_response *make_rx_response(struct xenvif *vif, diff --git a/drivers/net/xen-netback/xenbus.c b/drivers/net/xen-netback/xenbus.c index 1791807..6822d89 100644 --- a/drivers/net/xen-netback/xenbus.c +++ b/drivers/net/xen-netback/xenbus.c @@ -141,6 +141,15 @@ static int netback_probe(struct xenbus_device *dev, goto abort_transaction; } + /* Split event channels support */ + err = xenbus_printf(xbt, dev->nodename, + "feature-split-event-channels", + "%u", 1); + if (err) { + message = "writing feature-split-event-channels"; + goto abort_transaction; + } + err = xenbus_transaction_end(xbt, 0); } while (err == -EAGAIN); @@ -419,7 +428,7 @@ static int connect_rings(struct backend_info *be) { struct xenvif *vif = be->vif; struct xenbus_device *dev = be->dev; - unsigned int evtchn, rx_copy; + unsigned int tx_evtchn, rx_evtchn, rx_copy; int err; int val; unsigned long tx_ring_ref[NETBK_MAX_RING_PAGES]; @@ -428,12 +437,22 @@ static int connect_rings(struct backend_info *be) unsigned int rx_ring_order; err = xenbus_gather(XBT_NIL, dev->otherend, - "event-channel", "%u", &evtchn, NULL); + "event-channel", "%u", &tx_evtchn, NULL); if (err) { - xenbus_dev_fatal(dev, err, - "reading %s/event-channel", - dev->otherend); - return err; + /* try split event channels */ + err = xenbus_gather(XBT_NIL, dev->otherend, + "event-channel-tx", "%u", &tx_evtchn, + "event-channel-rx", "%u", &rx_evtchn, + NULL); + if (err) { + xenbus_dev_fatal(dev, err, + "reading %s/event-channel(-tx/rx)", + dev->otherend); + return err; + } + } else { /* frontend doesn't support split event channels */ + rx_evtchn = tx_evtchn; + dev_info(&dev->dev, "single event channel\n"); } err = xenbus_scanf(XBT_NIL, dev->otherend, "tx-ring-order", "%u", @@ -568,12 +587,19 @@ static int connect_rings(struct backend_info *be) /* Map the shared frame, irq etc. */ err = xenvif_connect(vif, tx_ring_ref, (1U << tx_ring_order), rx_ring_ref, (1U << rx_ring_order), - evtchn); + tx_evtchn, rx_evtchn); if (err) { /* construct 1 2 3 / 4 5 6 */ int i; char txs[3 * (1U << MODPARM_netback_max_tx_ring_page_order)]; char rxs[3 * (1U << MODPARM_netback_max_rx_ring_page_order)]; + char evtchns[20]; + + if (tx_evtchn == rx_evtchn) + snprintf(evtchns, sizeof(evtchns)-1, "%u", tx_evtchn); + else + snprintf(evtchns, sizeof(evtchns)-1, "%u/%u", + tx_evtchn, rx_evtchn); txs[0] = rxs[0] = 0; @@ -586,8 +612,8 @@ static int connect_rings(struct backend_info *be) " %lu", rx_ring_ref[i]); xenbus_dev_fatal(dev, err, - "mapping shared-frames%s /%s port %u", - txs, rxs, evtchn); + "mapping shared-frames%s /%s port %s", + txs, rxs, evtchns); return err; } return 0;
Netback and netfront only use one event channel to do tx / rx notification. This may cause unnecessary wake-up of process routines. This patch adds a new feature called feautre-split-event-channel to netback, enabling it to handle Tx and Rx event separately. Netback will use tx_irq to notify guest for tx completion, rx_irq for rx notification. If frontend doesn't support this feature, tx_irq = rx_irq. Signed-off-by: Wei Liu <wei.liu2@citrix.com> --- drivers/net/xen-netback/common.h | 10 +++-- drivers/net/xen-netback/interface.c | 78 ++++++++++++++++++++++++++++------- drivers/net/xen-netback/netback.c | 7 ++-- drivers/net/xen-netback/xenbus.c | 44 ++++++++++++++++---- 4 files changed, 109 insertions(+), 30 deletions(-)