On Fri, Nov 3, 2017 at 2:32 AM, Kaartic Sivaraam
<kaartic.sivaraam@xxxxxxxxx> wrote:
> On Monday 23 October 2017 11:07 PM, Stefan Beller wrote:
>>
>> Exactly. By memory I mean volatile RAM (as opposed to
>> memory on a spinning disk).
>>
>> Using GIT_TEST_OPTS has had some issues (I remember vaguely
>> there was an inconsistency between the output of `make test` and prove),
>> so I put my entire working tree on a tmpfs, I run roughly this script
>> after booting my computer:
>>
>> sudo mount -t tmpfs -o size=16g tmpfs /u
>> mkdir /u/git
>> echo "gitdir:
>> /usr/local/google/home/sbeller/OSS/git/.git/worktrees/git"
>>>
>>> /u/git/.git
>>
>> git -C /u/git checkout -f HEAD
>>
>> cat <<EOF >/u/config.mak
>> DEVELOPER=1
>> DEVELOPERS=1
>> CFLAGS += -g -O2
>> CFLAGS += -DFLEX_ARRAY=2048
>> #CFLAGS += -Wno-unused-value
>> EOF
>
>
> Did I thank you for a good explanation? If not, thanks that was interesting
> and enlightening.
>
>> The test suite (excluding t9*) runs in less than 50 seconds on the ram
>> disk.
>>
Just tested again, I meant to say 70s instead of 50s.
> BTW, this is what I call _way way_ faster. Unfortunately due to the limited
> configuration of my system, the test suite has following timing
>
> real 3m14.482s
> user 2m10.556s
> sys 1m12.328s
This sounds to me as if it is running with just one thread
(because sys+user = real); I usually run with
cd t
prove --jobs 25 t[0-8][0-9]*.sh
The multithreading can be seen in the timing as well
real 1m9.913s
user 1m50.796s
sys 0m54.092s
as user > real already.
If you run tests via 'make test' or 'cd t && make', you can also give
a --jobs <n>
to make it faster. I have no good answer for how many, but I have the impression
overloading the system is no big deal. (I only have a few cores in this machine,
4 or 6, but still run with --jobs 25; 'git grep sleep' returns a
couple of lines,
and such threads sleeping definitely don't need a CPU)
Thanks,
Stefan
