From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Mosberger Date: Thu, 20 Nov 2003 06:01:18 +0000 Subject: Re: [PATCH] - sched_clock() broken for ia64 SN platform Message-Id: List-Id: References: In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-ia64@vger.kernel.org >>>>> On Wed, 19 Nov 2003 20:09:15 -0800, "John Hawkes" said: John> I'd like to hear an argument about why sched_clock() needs John> sub-microsecond accuracy, instead of just using jiffies, when John> one use of sched_clock() is to compare a delta time against John> cache_decay_ticks, which is a "jiffies"-granularity value, and John> the other use is to determine the relative John> computebound-vs-interactive characteristics of the process. It's probably best to discuss this on lkml. I didn't follow all the recent scheduler developments but AFAIK, this is largely driven by trying to fix some scheduling corners. I think the "persistent starvation" bug that Stephane found gets fixed by it, for example. Also, supposedly it helps interactivity. --david