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From: Chris Friesen <cfriesen@nortelnetworks.com>
To: root@chaos.analogic.com
Cc: Chuck Lever <cel@citi.umich.edu>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: timer question
Date: Thu, 01 Apr 2004 01:10:00 -0500	[thread overview]
Message-ID: <406BB238.2050207@nortelnetworks.com> (raw)
In-Reply-To: Pine.LNX.4.53.0403311628120.12948@chaos

Richard B. Johnson wrote:
> On Wed, 31 Mar 2004, Chuck Lever wrote:
> 
> 
>>hi all-
>>
>>i'm looking for a way to do microsecond resolution timing in the RPC
>>client.  i need a timer or timestamp function that is fairly cheap, that i
>>can call on any hardware platform, and that i can invoke from inside a
>>bottom half.
>>
>>any suggestions?

As Dick Johnson said, x86 has rdtsc.  PowerPC has the mftbr, which is 
equivalent.  MIPS has something similar.

Many architectures have something, but currently it has to be coded for 
each.

One thing that might be nice would be a common API to get a high-res 
timestamp, something like a 64-bit nano_uptime, which would be good for 
uptimes of up to 524 years at nanosecond precision.  Or else you could 
just use timespec, although its not as nice on actual 64-bit machines.

Chris


  reply	other threads:[~2004-04-01  6:10 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2004-03-31 21:11 timer question Chuck Lever
2004-03-31 21:31 ` Richard B. Johnson
2004-04-01  6:10   ` Chris Friesen [this message]
  -- strict thread matches above, loose matches on Subject: below --
2002-03-05 13:57 Emmanuel Chaput

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