On Mon, 2015-02-09 at 10:45 +0800, Robert Yang wrote: > On 02/06/2015 10:46 PM, Bob Friesenhahn wrote: > > On Fri, 6 Feb 2015, Robert Yang wrote: > > > >> > >> > >> On 02/06/2015 12:12 PM, Bob Friesenhahn wrote: > >>> I am not seeing quite the difference between libtool releases that you are > >>> although I see a big slowdown starting with 2.4.3. These timings are for > >>> optimized builds of GraphicsMagick on a 12-core GNU/Linux system using -j > >>> 12: > >> > >> I think that we can't see obviously slowdown by "make -jN", > >> but "make -j1" will. And bash is much slower than dash, I'm trying to > >> figure out why. > > > > It seems like this issue is already corrected in the source tree but you are > > Yes, I think that the git repo has fixed the problem: > > commit 408cfb9c5fa8a666917167ffb806cb19deded429 > Author: Gary V. Vaughan <g...@gnu.org> > Date: Fri Feb 6 12:58:34 2015 +0000 > > libtool: don't execute automake and autoconf on every invocation.
In an effort to get to the bottom of this I made a git bisection, timing the performance of building xz with make -j1 using each different libtool. The issues come down to this commit: http://git.savannah.gnu.org/cgit/libtool.git/commit/?id=0a42997c6032b9550a009a271552e811bfbcc430 libtool: rewritten over funclib.sh instead of general.m4sh. Before that, I get a time of about 20s, after it, 39s. If I cherry-pick in the fix in master mentioned above, I get 27s. So whilst things are better (thanks!), the above change is still causing a regression in the performance somewhere else. Any ideas what else in that rather large change may be causing this? Cheers, Richard _______________________________________________ https://lists.gnu.org/mailman/listinfo/libtool