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Re: performance improvements

To: Kanoj Sarcar <kanoj@xxxxxxxxxxxxxxxxxxx>
Subject: Re: performance improvements
From: Ralf Baechle <ralf@xxxxxxxxxxx>
Date: Sun, 30 Jul 2000 13:39:42 +0200
Cc: linux-origin@xxxxxxxxxxx
In-reply-to: <200007300123.SAA92252@google.engr.sgi.com>; from kanoj@google.engr.sgi.com on Sat, Jul 29, 2000 at 06:23:48PM -0700
References: <200007300123.SAA92252@google.engr.sgi.com>
Sender: owner-linux-origin@xxxxxxxxxxx
On Sat, Jul 29, 2000 at 06:23:48PM -0700, Kanoj Sarcar wrote:

> And after the recent tlbflush optimizations:
> 
> SMP
> ---
> 771.97user 55.22system 4:24.73elapsed 312%CPU (0avgtext+0avgdata 
> 0maxresident)k
> 0inputs+0outputs (508064major+1831879minor)pagefaults 0swaps
> 
> I am still trying to figure out the DISCONTIGMEM problem, but at least
> it seems that on specific memory configurations, not ignoring the 128Mb
> memory on the 7th bank seems to create problems. Go figure.

I'm rewriting some important routines like memcpy, memmove and ip checksums.
As a result of the first crude test implementation the results of
microbenchmarks like lmbench have increased significantly, sometimes beyond
factor of two.

A analysis of lmbench also shows that some of our number degrade much worse
than IRIX's for large datasets; the graphs seem to indicate that the lack
of cache colouring is the cause.

  Ralf

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