Messages in this thread | | | Subject | Re: Linux 2.4.2 fails to merge mmap areas, 700% slowdown. | From | (Kevin Buhr) | Date | 20 Mar 2001 19:20:28 -0600 |
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Linus Torvalds <torvalds@transmeta.com> writes: > > Cool. Somebody actually found a real case. > > I'll fix the mmap case asap. Its' not hard, I just waited to see if it > ever actually triggers. Something like g++ certainly counts as major.
I frequently build Mozilla from scratch on my (aging) dual Celeron machine. That's about 65 megs of actual C++ source, and it takes about an hour of real time to compile. I see times for the whole build like this:
real 60m4.574s user 101m18.260s sys 3m23.520s
with gcc 2.95.2 20000220 (Debian GNU/Linux) under Linux 2.4.2.
The sys-to-user ratio seems much closer to Serge's 2.2.13 numbers than his 2.4.2 numbers, and I'm wondering why.
If I recall correctly, RedHat's 2.96 was a modified development snapshot of GCC 3.0, not an official GCC release. If this is just a quirk in 2.96 that can be fixed before the official release of 3.0 by a trivial patch to libiberty, maybe your original hunch was right and the kernel should be left as-is.
> Are you willing to test out patches?
I'm willing to help test out the patch; I'd be curious to see what effect it has on the performance of 2.95.2.
Kevin <buhr@stat.wisc.edu> - 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/
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