lkml.org 
[lkml]   [2001]   [Sep]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: Purpose of the mm/slab.c changes
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

--
"Embrace, Enhance, Eliminate" - it worked for the pope, it'll work for Bill.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 13:03    [W:0.069 / U:0.700 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site