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Re: Using -MMD instead of -MD for depndency generation
From: |
Paul Smith |
Subject: |
Re: Using -MMD instead of -MD for depndency generation |
Date: |
Sun, 31 Oct 2010 13:24:31 -0400 |
On Thu, 2010-10-28 at 12:18 -0400, Paul Smith wrote:
> > Is there anything I can help with? bisect GNU make 3.81 -> 3.82 to see when
> > it
> > got slower? Or anything on our GNU make/automake usage? E.g. we use a non
> > recursive makefile
>
> I'll try to look into this more this afternoon/tonight. Until then I
> wouldn't bother doing too much work on it. Let me try to reproduce your
> results then we can see where we are.
I was able to install the proper packages and get a complete build of
WebKit.
After this I see that GNU make 3.82 is twice as slow as 3.81, but even
3.82 only takes about 30 seconds to run (a do-nothing build) on my
system. Taking 5+ minutes is crazy. There must be something odd about
your system or setup causing this.
As for why 3.82 is slower, unfortunately I'm having problems figuring it
out. I compiled with gprof but the cumulative profiled code in GNU make
only took 6 seconds or so, so I suppose the other 24 seconds must be in
libc or someplace... but trying to install a profile-enabled version of
libc on my system did not succeed (or rather the package install worked
but linking with the profiled libc did not work).
All I can assume is there's some difference in heap management in 3.82
which is causing this, because that's the only difference I can think of
that would not show up in the GNU make code itself. I'll try using
valgrind and see what I get. If anyone has other suggestions for
profiling tools let me know.
Cheers!
--
-------------------------------------------------------------------------------
Paul D. Smith <address@hidden> Find some GNU make tips at:
http://www.gnu.org http://make.mad-scientist.net
"Please remain calm...I may be mad, but I am a professional." --Mad Scientist
- Using -MMD instead of -MD for depndency generation, Holger Freyther, 2010/10/23
- Re: Using -MMD instead of -MD for depndency generation, Ralf Wildenhues, 2010/10/25
- Re: Using -MMD instead of -MD for depndency generation, Holger Freyther, 2010/10/26
- Re: Using -MMD instead of -MD for depndency generation, Ralf Wildenhues, 2010/10/27
- Re: Using -MMD instead of -MD for depndency generation, Paul Smith, 2010/10/27
- Re: Using -MMD instead of -MD for depndency generation, Ralf Wildenhues, 2010/10/27
- Re: Using -MMD instead of -MD for depndency generation, Holger Freyther, 2010/10/27
- Re: Using -MMD instead of -MD for depndency generation, Paul Smith, 2010/10/28
- Re: Using -MMD instead of -MD for depndency generation,
Paul Smith <=
- Re: Using -MMD instead of -MD for depndency generation, Holger Freyther, 2010/10/31
- Re: Using -MMD instead of -MD for depndency generation, Miles Bader, 2010/10/31