Re: 405 TLB miss reduction

On 12/10/2003 06:08 PM Dan Malek wrote:

Wolfgang Grandegger wrote:

quoted

....We
can regain a few percent by using the kernel option CONFIG_PIN_TLB
but we are thinking about further kernel modifications to reduce
TLB misses. What comes into my mind is:

If you have a large application I doubt any kernel modification
will gain much.  It's the application causing the huge amounts
of tlb misses, you probably need to evaluate changes that will
reduce that.

It's always easy to pick on the kernel and make some changes
becaue it is a very static and well behaved application.  It
seems your biggest performance increase would come from the
analysis of the application and some redesign to improve its
use of system resources.

We have been surprised, that CONFIG_PIN_TLB was able to reduce the page
miss rate already by approx. 40%. We are also working on the
optimization/tuning of our application and likely there we can gain more
than by further squeezing the TBL management of the Linux kernel, I agree.

Thanks.

Wolfgang.


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