From: Herbert Xu Date: Tue, 9 May 2006 22:27:54 +0000 (-0700) Subject: [NET] linkwatch: Handle jiffies wrap-around X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=8c1056839e808aad728db86d739ffec71d2d1db8;p=linux-beck.git [NET] linkwatch: Handle jiffies wrap-around The test used in the linkwatch does not handle wrap-arounds correctly. Since the intention of the code is to eliminate bursts of messages we can afford to delay things up to a second. Using that fact we can easily handle wrap-arounds by making sure that we don't delay things by more than one second. This is based on diagnosis and a patch by Stefan Rompf. Signed-off-by: Herbert Xu Acked-by: Stefan Rompf Signed-off-by: David S. Miller --- diff --git a/net/core/link_watch.c b/net/core/link_watch.c index 341de44c7ed1..646937cc2d84 100644 --- a/net/core/link_watch.c +++ b/net/core/link_watch.c @@ -170,13 +170,13 @@ void linkwatch_fire_event(struct net_device *dev) spin_unlock_irqrestore(&lweventlist_lock, flags); if (!test_and_set_bit(LW_RUNNING, &linkwatch_flags)) { - unsigned long thisevent = jiffies; + unsigned long delay = linkwatch_nextevent - jiffies; - if (thisevent >= linkwatch_nextevent) { + /* If we wrap around we'll delay it by at most HZ. */ + if (!delay || delay > HZ) schedule_work(&linkwatch_work); - } else { - schedule_delayed_work(&linkwatch_work, linkwatch_nextevent - thisevent); - } + else + schedule_delayed_work(&linkwatch_work, delay); } } }