[systemd-devel] [PATCH] use dolt.m4 to speedup compilation

[Lucas De Marchi]

On Thu, Mar 5, 2015 at 9:58 PM,  <josh at joshtriplett.org> wrote:
> On Fri, Mar 06, 2015 at 12:55:38AM +0100, Michael Biebl wrote:
>> 2015-03-05 11:58 GMT+01:00  <harald at redhat.com>:
>> > From: Harald Hoyer <harald at redhat.com>
>> >
>> > The speedup is significant
>> >
>> > Original libtool
>> > $ ccache -C && make clean && time make -j4
>> > […]
>> > real    6m4.104s
>> > user    13m49.234s
>> > sys    7m37.864s
>> >
>> > Original libtool + dolt
>> > $ ccache -C && make clean && time make -j4
>> > […]
>> > real    2m24.869s
>> > user    7m30.198s
>> > sys    1m17.813s
>>
>> Hm, the speedup is nowhere near as significant here:
>> without dolt (make):
>> real 4m2.749s
>> user 3m9.304s
>> sys 0m19.032s
>>
>> with dolt (make):
>> real 3m33.756s
>> user 2m59.476s
>> sys 0m17.632s
>>
>> without dolt (make -j6):
>> real 1m42.001s
>> user 5m3.680s
>> sys 0m26.608s
>>
>> with dolt (make -j6)
>> real 1m35.267s
>> user 4m50.956s
>> sys 0m24.724s
>>
>>
>> libtool version is 2.4.2.
>
> That's more what I'd expect with current versions of libtool, which has
> supposedly fixed many of the issues that motivated the creation of dolt
> in the first place.

Maybe it was a regression in libtool from 2.4.2 <-> 2.4.5?  I have 2.4.5 here:

make -j6, libtool
real    4m53.924s
user    11m4.323s
sys     0m54.880s

make -j6, dolt
real    1m58.653s
user    6m20.523s
sys     0m28.920s


-- 
Lucas De Marchi