Subject: Re: Please Revert newlock2
To: Bucky Katz <>
From: Perry E. Metzger <>
List: tech-kern
Date: 02/18/2007 14:22:05
Bucky Katz <> writes:
>> 2) Either cause them to perform acceptably for your application, or else
>>    endeavor to get M:N back in a supported state for uniprocessors.
> It has to be the later. The context switch overhead of 1:1 on ARM will
> cause a severe performance degradation.

I'm not sure about that. The experience of Solaris and other unices
has been that a tuned 1:1 isn't that bad, whereas M:N is very hard to
make work correctly. It might be easier to tune 1:1 for ARM than to
make M:N work correctly again. A little effort spent on speeding up
the system call path and the scheduler could pay off quite handsomely.

Perry E. Metzger