Subject: Re: Please Revert newlock2
To: None <tech-kern@netbsd.org>
From: Eric Haszlakiewicz <erh@swapsimple.com>
List: tech-kern
Date: 02/18/2007 12:54:40
On Sun, Feb 18, 2007 at 06:50:38PM +0000, David Laight wrote:
> On Sun, Feb 18, 2007 at 10:29:42AM -0800, Bucky Katz wrote:
> > 
> > It has to be the later. The context switch overhead of 1:1 on ARM will
> > cause a severe performance degradation.
> 
> That shouldn't matter.
> Siince the threads share the VM space, the cache flushing needn't be done.
> So there isn't any expensive context switch to do when one LWP wakes
> another in the ame process.

This sounds like something begging for a before-and-after benchmark.
Does anyone have time (and hardware) to do such a benchmark?

eric