Re: [kvm-unit-tests PATCH 2/2] run_tests: allow run tests in parallel

["Radim Krčmář" <rkrcmar@redhat.com>]

2017-01-03 10:45+0800, Peter Xu:
> On Mon, Jan 02, 2017 at 09:18:24PM +0100, Radim Krčmář wrote:
>> 2017-01-01 18:34+0800, Peter Xu:
>> > diff --git a/scripts/functions.bash b/scripts/functions.bash
>> Couldn't the queue be much simpler ...
>> 
>> > +	else
>> > +		RUNTIME_log_file=$ut_default_log_file
>> > +		"$@"
>> > +	fi
>> >  }
>> >  
>> >  function for_each_unittest()
>> > @@ -51,5 +62,10 @@ function for_each_unittest()
>> >  		fi
>> >  	done
>> 
>> ... like this:
>> 
>>   while [ "`jobs | wc -l`" -gt $ut_run_queues ]; do

(Uh, should be -ge, and `wc -l` always has reasonable output, so quotes
 are not necessary.  Quotes would make more sense around the variable.)

>>     wait
> 
> I suppose you mean "wait -n" here?

Yes, sorry.

>                                    And also a "if" should suffice
> here, though a "while" won't hurt as well.

I agree.

(I was lazy to read the manual to confirm, hence the first mistake as
 well.  I just remembered that bash wait has this weird behavior and
 assumed that the wait in task_enqueue is already doing that ...)

>>   done
>>   run_task "$cmd" "$testname" "$groups" "$smp" "$kernel" "$opts" "$arch" "$check" "$accel" "$timeout" &
> 
> I think this might work, however it has assumption that these $cmd
> tasks are the only jobs that is running in the background.

Yes, but run_task is already in a sub shell, so its jobs don't matter
and we can easily guarantee that for_each_unit_test won't spawn more.

> I didn't notice the "-n" parameter for "wait", otherwise I won't
> bother using SIGUSR1 at all. :)

(Btw. why couldn't you use SIGCHLD?)