From 0d08fceb2e21c30ca3e1e462e678723f806acf18 Mon Sep 17 00:00:00 2001 From: David Vrabel Date: Fri, 16 May 2014 12:26:04 +0100 Subject: xen-netback: fix race between napi_complete() and interrupt handler When the NAPI budget was not all used, xenvif_poll() would call napi_complete() /after/ enabling the interrupt. This resulted in a race between the napi_complete() and the napi_schedule() in the interrupt handler. The use of local_irq_save/restore() avoided by race iff the handler is running on the same CPU but not if it was running on a different CPU. Fix this properly by calling napi_complete() before reenabling interrupts (in the xenvif_napi_schedule_or_enable_irq() call). Signed-off-by: David Vrabel Acked-by: Wei Liu Acked-by: Ian Campbell Signed-off-by: David S. Miller --- drivers/net/xen-netback/netback.c | 4 ++-- 1 file changed, 2 insertions(+), 2 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 64ab1d141f1c..7367208ee8cd 100644 --- a/drivers/net/xen-netback/netback.c +++ b/drivers/net/xen-netback/netback.c @@ -716,7 +716,7 @@ done: notify_remote_via_irq(vif->rx_irq); } -void xenvif_check_rx_xenvif(struct xenvif *vif) +void xenvif_napi_schedule_or_enable_events(struct xenvif *vif) { int more_to_do; @@ -750,7 +750,7 @@ static void tx_credit_callback(unsigned long data) { struct xenvif *vif = (struct xenvif *)data; tx_add_credit(vif); - xenvif_check_rx_xenvif(vif); + xenvif_napi_schedule_or_enable_events(vif); } static void xenvif_tx_err(struct xenvif *vif, -- cgit v1.2.3-59-g8ed1b