Re: 7.52 second kernel compile

From: Linus Torvalds (torvalds@transmeta.com)
Date: Mon Mar 18 2002 - 21:08:17 EST


On Mon, 18 Mar 2002, David S. Miller wrote:
>
> Or maybe the program is just flawed, and the interesting 1/8 pattern comes
> from something else altogether.
>
> I think the weird Athlon behavior has to do with the fact that
> you've made your little test program as much of a cache tester
> as a TLB tester :-)

Oh, I was assuming that malloc(BIG) would do a mmap() of MAP_ANONYMOUS,
which should make all the pages 100% shared, and thus basically zero cache
overhead on a physically indexed machine like an x86.

So it was designed to reall yonly stress the TLB, not the regular caches.

Although I have to admit that I didn't actually _test_ that hypothesis.

                Linus

-
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/



This archive was generated by hypermail 2b29 : Sat Mar 23 2002 - 22:00:17 EST