Re: [PATCH][2.5] hangcheck-timer

From: Joel Becker (
Date: Tue Jan 21 2003 - 12:40:02 EST

On Tue, Jan 21, 2003 at 12:50:39PM +0000, Dave Jones wrote:
> I'm puzzled. What does this do that softdog.c doesn't ?

        First, softdog.c requires userspace interaction. Second, softdog.c
relies on jiffies. If the system goes out to lunch via udelay() or
another hardware call that freezes the CPUs for a bit, jiffies does not
increment. The system could be frozen for two minutes (qla2x00 used to
do this for 90 seconds) and softdog.c never notices, because jiffies
hasn't counted a single second during this time.



"You cannot bring about prosperity by discouraging thrift. You cannot strengthen the weak by weakening the strong. You cannot help the wage earner by pulling down the wage payer. You cannot further the brotherhood of man by encouraging class hatred. You cannot help the poor by destroying the rich. You cannot build character and courage by taking away a man's initiative and independence. You cannot help men permanently by doing for them what they could and should do for themselves." - Abraham Lincoln

Joel Becker Senior Member of Technical Staff Oracle Corporation E-mail: Phone: (650) 506-8127 - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to More majordomo info at Please read the FAQ at

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