On Sun, Sep 09, 2001 at 01:58:44PM -0700, Davide Libenzi wrote:
> >> Do You see it as a plus ?
> >> The new allocated slab will be very likely written ( w/o regard
> >> about the old content ) and an L2 mapping will generate
> >> invalidate traffic.
> >
> > If your invalidates are slower than your RAM, you should
> > consider getting another computer.
>
> You mean a Sun, that uses a separate bus for snooping ? :)
> Besides to not under estimate the cache coherency traffic ( that on many CPUs
> uses the main memory bus ) there's the fact that the old data eventually
> present in L2 won't be used by the new slab user.
That's actually what having a slab cache of pre-initialized elements tries
to achieve.
On anything that uses a MESI-like cache coherence protocol a cached dirty
cache line that is written to will not cause any coherency traffic and
thus be faster.
Ralf
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This archive was generated by hypermail 2b29 : Sun Sep 23 2001 - 21:00:48 EST