From 0db1d6fc1ea051af49ebe03c503d23996a7c5bbb Mon Sep 17 00:00:00 2001 From: Matt Mackall Date: Thu, 11 Aug 2005 19:25:54 -0700 Subject: [PATCH] [NETPOLL]: add retry timeout Add limited retry logic to netpoll_send_skb Each time we attempt to send, decrement our per-device retry counter. On every successful send, we reset the counter. We delay 50us between attempts with up to 20000 retries for a total of 1 second. After we've exhausted our retries, subsequent failed attempts will try only once until reset by success. Signed-off-by: Matt Mackall Signed-off-by: David S. Miller --- include/linux/netpoll.h | 1 + net/core/netpoll.c | 13 ++++++++++--- 2 files changed, 11 insertions(+), 3 deletions(-) diff --git a/include/linux/netpoll.h b/include/linux/netpoll.h index bcd0ac33f592..be68d94b03d5 100644 --- a/include/linux/netpoll.h +++ b/include/linux/netpoll.h @@ -26,6 +26,7 @@ struct netpoll { struct netpoll_info { spinlock_t poll_lock; int poll_owner; + int tries; int rx_flags; spinlock_t rx_lock; struct netpoll *rx_np; /* netpoll that registered an rx_hook */ diff --git a/net/core/netpoll.c b/net/core/netpoll.c index 59ed186e4f46..d09affdbad3c 100644 --- a/net/core/netpoll.c +++ b/net/core/netpoll.c @@ -33,6 +33,7 @@ #define MAX_UDP_CHUNK 1460 #define MAX_SKBS 32 #define MAX_QUEUE_DEPTH (MAX_SKBS / 2) +#define MAX_RETRIES 20000 static DEFINE_SPINLOCK(skb_list_lock); static int nr_skbs; @@ -265,7 +266,8 @@ static void netpoll_send_skb(struct netpoll *np, struct sk_buff *skb) return; } - while (1) { + do { + npinfo->tries--; spin_lock(&np->dev->xmit_lock); np->dev->xmit_lock_owner = smp_processor_id(); @@ -277,6 +279,7 @@ static void netpoll_send_skb(struct netpoll *np, struct sk_buff *skb) np->dev->xmit_lock_owner = -1; spin_unlock(&np->dev->xmit_lock); netpoll_poll(np); + udelay(50); continue; } @@ -285,12 +288,15 @@ static void netpoll_send_skb(struct netpoll *np, struct sk_buff *skb) spin_unlock(&np->dev->xmit_lock); /* success */ - if(!status) + if(!status) { + npinfo->tries = MAX_RETRIES; /* reset */ return; + } /* transmit busy */ netpoll_poll(np); - } + udelay(50); + } while (npinfo->tries > 0); } void netpoll_send_udp(struct netpoll *np, const char *msg, int len) @@ -642,6 +648,7 @@ int netpoll_setup(struct netpoll *np) npinfo->rx_np = NULL; npinfo->poll_lock = SPIN_LOCK_UNLOCKED; npinfo->poll_owner = -1; + npinfo->tries = MAX_RETRIES; npinfo->rx_lock = SPIN_LOCK_UNLOCKED; } else npinfo = ndev->npinfo;