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Re: strange top statistics for 3.1 cc1
- To: chowell2 at pacbell dot net (Colin Douglas Howell)
- Subject: Re: strange top statistics for 3.1 cc1
- From: Brad Lucier <lucier at math dot purdue dot edu>
- Date: Sun, 26 Aug 2001 22:57:04 -0500 (EST)
- Cc: lucier at math dot purdue dot edu (Brad Lucier), gcc at gcc dot gnu dot org
> Brad Lucier wrote:
> > > Could you give a source file and a cc1 command line to help track
> > > this down?
> > [lucier@curie lib]$ gcc -fpic -fomit-frame-pointer -O1 -fno-math-errno -fschedule-insns2 -fno-strict-aliasing -Wall -W -Wno-unused -c -I. -D___PRIMAL -D___LIBRARY -D___SHARED -D___SINGLE_HOST _num.c -save-temps
> > and
> > http://www.math.purdue.edu/~lucier/_num.i.gz
> Some remarks. I am using the trunk checked out today, configured
> identically to yours
> (except for --prefix). I am also running Red Hat 7.1, with the updated
> 2.4.3-12 kernel,
> on a 533 MHz Celeron box.
> This case is weird. When I first started running the testcase, it
> looked as though I
> wasn't seeing your problem. I let it run for some 14 CPU minutes and
> never saw any
> sign of excessive system CPU usage.
> Then I tried running it again under /usr/bin/time, so that I could get a
> total cpu usage
> report, and went to do other things.
> Well, it's still running, having consumed more than 160 CPU minutes!
> And now I see the
> system CPU usage effect you describe. I tried attaching to the process
> under GDB, and
> I saw it was bogged down in split_all_insns() at line 3486 of toplev.c,
> doing lots of
> sbitmap operations. Doing strace -p on the process showed that it was
> performing lots of
> mmap2() and munmap() calls, each mapping and unmapping a large sbitmap
> (about 11 MB).
> I think this is where some of your excessive system CPU usage is coming
> Just how long did it take you to compile this testcase, anyway?
I don't know, I went to bed and it was done in the morning.
> (This reply probably won't show up on the list. It looks like the Pac
> Bell SMTP server
> I use has been ORBL'd due to some <bleep> who attached an open relay to
So I kept the whole message in my reply.