Re: [Qemu-devel] Help needed: test-qht-par hangs on Travis

[Eduardo Habkost <ehabkost@redhat.com>]

On Sun, Dec 09, 2018 at 05:27:38PM -0500, Emilio G. Cota wrote:
> On Fri, Dec 07, 2018 at 18:41:07 -0200, Eduardo Habkost wrote:
> > I've noticed QEMU Travis builds are failing recently, and they
> > seem to happen only on the --enable-gprof jobs.  I have enabled
> > V=1 and noticed that the jobs are hanging inside test-qht-par.
> > 
> > Example here (look for "/qht/parallel/2threads-0%updates-1s"):
> > 
> > https://travis-ci.org/ehabkost/qemu-hacks/jobs/465081311
> > 
> > Does anybody have any idea why?
> 
> So if I read that output correctly, it seems that the second
> test in qht-par never completes.
> 
> Enabling gprof and gcov (as in that build) should just lower
> the throughput of the benchmark (test-qht-par invokes qht-bench),
> but the duration should be the same (1 second per test, so no need
> to wait for 10 minutes).
> 
> Can you try re-running the test, after applying the appended patch?
> (It disables the "resize" thread.)

It is running right now, here:
https://travis-ci.org/ehabkost/qemu-hacks/jobs/466074591

> 
> Also, does it reliably hang on Travis, or are these hangs
> intermittent?

It can be reproduced reliably.  qemu.git builds are failing since
Thursday:
https://travis-ci.org/qemu/qemu/builds

> 
> Thanks,
> 
> 		Emilio
> ---
> diff --git a/tests/test-qht-par.c b/tests/test-qht-par.c
> index d8a83caf5c..83ac92e430 100644
> --- a/tests/test-qht-par.c
> +++ b/tests/test-qht-par.c
> @@ -6,7 +6,7 @@
>   */
>  #include "qemu/osdep.h"
> 
> -#define TEST_QHT_STRING "tests/qht-bench 1>/dev/null 2>&1 -R -S0.1 -D10000 -N1 "
> +#define TEST_QHT_STRING "tests/qht-bench 1>/dev/null 2>&1 -R "
> 
>  static void test_qht(int n_threads, int update_rate, int duration)
>  {
> 

-- 
Eduardo