Patch for optimize context switch
Gabriel Paubert
paubert at iram.es
Tue Feb 22 22:50:19 EST 2000
On Tue, 22 Feb 2000, FASSINO Jean-Philippe wrote:
> FASSINO Jean-Philippe wrote:
>
> > FASSINO Jean-Philippe wrote:
> >
> > ------------------------------------------------------------------------
> > Context switching - times in microseconds - smaller is better
> > -------------------------------------------------------------
> > Host OS 2p/0K 2p/16K 2p/64K 8p/16K 8p/64K 16p/16K 16p/64K
> > ctxsw ctxsw ctxsw ctxsw ctxsw ctxsw ctxsw
> > --------- ------------- ----- ------ ------ ------ ------ ------- -------
> > ppc-linux Linux 2.2.15p 1 7 90 26 107 31 222
> > ppc-linux Linux 2.2.15p 1 7 91 26 110 29 257
> > ppc-linux Linux 2.2.15p 1 7 90 25 112 26 233
> > ppc-linux Linux 2.2.15p 1 7 92 25 126 27 243
> > ppc-linux Linux 2.2.15p 1 7 147 26 150 27 245
>
> > ppc-linux Linux 2.2.15p 0 7 92 25 136 28 270
> > ppc-linux Linux 2.2.15p 1 8 90 27 103 27 211
> > ppc-linux Linux 2.2.15p 0 9 90 30 112 32 228
> > ppc-linux Linux 2.2.15p 1 7 91 25 130 29 277
> > ppc-linux Linux 2.2.15p 1 7 90 25 105 26 211
>
> Sorry i forgot to say :
> - 5 first run is without patch
> - 5 last run is with path
That's largely in the noise: results with processes which do not pollute
cache are slightly better wit the patch. But I don't consider this a real
life situation. Processes which actually do some work don't see any
practical difference. The 147 microseconds in the 3rd column is very
probably a bogus point due to collision on L2 cache which is only 2 way
set associative.
Gabriel.
** Sent via the linuxppc-dev mail list. See http://lists.linuxppc.org/
More information about the Linuxppc-dev
mailing list