From: Ben Pfaff Date: Thu, 20 Mar 2014 17:45:21 +0000 (-0700) Subject: openvswitch: Correctly report flow used times for first 5 minutes after boot. X-Git-Url: http://pileus.org/git/?p=~andy%2Flinux;a=commitdiff_plain;h=f9b8c4c8baded129535d82d74df8e87a7a369f54 openvswitch: Correctly report flow used times for first 5 minutes after boot. The kernel starts out its "jiffies" timer as 5 minutes below zero, as shown in include/linux/jiffies.h: /* * Have the 32 bit jiffies value wrap 5 minutes after boot * so jiffies wrap bugs show up earlier. */ #define INITIAL_JIFFIES ((unsigned long)(unsigned int) (-300*HZ)) The loop in ovs_flow_stats_get() starts out with 'used' set to 0, then takes any "later" time. This means that for the first five minutes after boot, flows will always be reported as never used, since 0 is greater than any time already seen. Signed-off-by: Ben Pfaff Acked-by: Pravin B Shelar Signed-off-by: Jesse Gross --- diff --git a/net/openvswitch/flow.c b/net/openvswitch/flow.c index d71e60fa28c..dda451f4429 100644 --- a/net/openvswitch/flow.c +++ b/net/openvswitch/flow.c @@ -92,7 +92,7 @@ static void stats_read(struct flow_stats *stats, unsigned long *used, __be16 *tcp_flags) { spin_lock(&stats->lock); - if (time_after(stats->used, *used)) + if (!*used || time_after(stats->used, *used)) *used = stats->used; *tcp_flags |= stats->tcp_flags; ovs_stats->n_packets += stats->packet_count;