From e1f00a69ec26e3eb9847c61c665b8fb3f0c6b477 Mon Sep 17 00:00:00 2001 From: Wei Liu Date: Wed, 22 May 2013 06:34:45 +0000 Subject: xen-netback: split event channels support for Xen backend driver Netback and netfront only use one event channel to do TX / RX notification, which may cause unnecessary wake-up of processing routines. This patch adds a new feature called feature-split-event-channels to netback, enabling it to handle TX and RX events 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 equals to rx_irq. Signed-off-by: Wei Liu Signed-off-by: David S. Miller --- drivers/net/xen-netback/netback.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) (limited to 'drivers/net/xen-netback/netback.c') diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c index 2d9477fd900f..82576fffb452 100644 --- a/drivers/net/xen-netback/netback.c +++ b/drivers/net/xen-netback/netback.c @@ -47,6 +47,13 @@ #include #include +/* Provide an option to disable split event channels at load time as + * event channels are limited resource. Split event channels are + * enabled by default. + */ +bool separate_tx_rx_irq = 1; +module_param(separate_tx_rx_irq, bool, 0644); + /* * This is the maximum slots a skb can have. If a guest sends a skb * which exceeds this limit it is considered malicious. @@ -662,7 +669,7 @@ 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; @@ -771,7 +778,6 @@ 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); @@ -783,7 +789,7 @@ 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); } @@ -1762,7 +1768,7 @@ 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, -- cgit v1.2.3-55-g7522