2003-03-18 20:08:51

by Pascal Schmidt

[permalink] [raw]
Subject: Re: [Bug 350] New: i386 context switch very slow compared to 2.4 due to wrmsr (performance)

On Tue, 18 Mar 2003 19:40:10 +0100, you wrote in linux.kernel:

> vendor_id : AuthenticAMD
> cpu family : 6
> model : 6
> model name : AMD Athlon(tm) Processor
> stepping : 2
> cpu MHz : 1409.946
> empty overhead=11 cycles
> load overhead=5 cycles
> I$ load overhead=5 cycles
> I$ load overhead=5 cycles
> I$ store overhead=826 cycles
>
> The Athlon XP shows really bad behavior when you store to the text area.

There seems to be a (surprising?) difference between AthlonXP model 6 and
model 8:

processor : 0
vendor_id : AuthenticAMD
cpu family : 6
model : 8
model name : AMD Athlon(tm) XP 1700+
stepping : 0

empty overhead=16 cycles
load overhead=1 cycles
I$ load overhead=2 cycles
I$ load overhead=1 cycles
I$ store overhead=81 cycles

--
Ciao,
Pascal