Re: [PATCH] - sched_clock() broken for ia64 SN platform

From: Robin Holt <>
Date: 2003-11-21 06:23:18
On Thu, Nov 20, 2003 at 10:32:29AM -0800, David Mosberger wrote:
> >>>>> On Thu, 20 Nov 2003 09:23:35 -0600, Jack Steiner <> said:
>   Jack> This is slightly off-topic, but the shared platform counter on
>   Jack> the SGI platform isnt a single counter. The counter is
>   Jack> replicated in each chipset It is synchronized thruout the
>   Jack> system so that all cpus will see the same value - ie., no
>   Jack> drift. Reading the counter does not required any off-node
>   Jack> references. There shouldnt be any scaling issues.
> Ah, that's good.  Just for future reference, what's the approximate
> latency of reading this counter?

I haven't tested it recently, but it was approx 55nSec on a 900Mhz

To unsubscribe from this list: send the line "unsubscribe linux-ia64" in
the body of a message to
More majordomo info at
Received on Thu Nov 20 14:26:13 2003

This archive was generated by hypermail 2.1.8 : 2005-08-02 09:20:20 EST