[PATCH] [RFC] Emulate "lwsync" to run standard user land on e500 cores

Scott Wood scottwood at freescale.com
Tue Oct 29 04:52:07 EST 2013


On Fri, 2013-10-25 at 10:25 -0500, James Yang wrote:
> On Fri, 25 Oct 2013, Scott Wood wrote:
> 
> > Has anyone measured how much this slows things down with a typical
> > userspace?
> 
> Not a measurement of the patch in question but an older similar patch 
> on 3.0.51 (8572 running Debian 5.0.3):
> 
> $ ./test-lwsync 
> cycles per emulated lwsync = 371
> cycles per sync = 36

My point was more to find out how often a typical userspace executes
these instructions.  From Wolfgang's e-mail it seems the answer is not
very often.

-Scott





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