| Message ID | 20110314175439.377973202@vyatta.com |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
--- a/net/ipv4/tcp_cubic.c 2011-03-11 09:00:06.856664687 -0800 +++ b/net/ipv4/tcp_cubic.c 2011-03-11 09:02:11.685796371 -0800 @@ -342,9 +342,11 @@ static void hystart_update(struct sock * u32 curr_jiffies = jiffies; /* first detection parameter - ack-train detection */ - if (curr_jiffies - ca->last_jiffies <= msecs_to_jiffies(2)) { + if ((s32)(curr_jiffies - ca->last_jiffies) <= + msecs_to_jiffies(2)) { ca->last_jiffies = curr_jiffies; - if (curr_jiffies - ca->round_start >= ca->delay_min>>4) + if ((s32) (curr_jiffies - ca->round_start) > + ca->delay_min >> 4) ca->found |= HYSTART_ACK_TRAIN; }
Jiffies wraps around therefore the correct way to compare is to use cast to signed value. Note: cubic is not using full jiffies value on 64 bit arch because using full unsigned long makes struct bictcp grow too large for the available ca_priv area. Includes correction from Sangtae Ha to improve ack train detection. Signed-off-by: Stephen Hemminger <shemminger@vyatta.com> -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html