Re: [DTrace-devel] [PATCH v2] test: Wait for output to flush out in enable_pid

Kris Van Hees
2025-07-31T00:17:28Z

On Wed, Jul 30, 2025 at 06:39:48PM -0400, Kris Van Hees wrote:
> On Wed, Jul 30, 2025 at 06:03:39PM -0400, Eugene Loh wrote:
> > On 7/30/25 10:26, Kris Van Hees wrote:
> >
> > > On Wed, Jul 30, 2025 at 10:18:17AM -0400, Kris Van Hees via DTrace-devel wrote:
> > > > I still see intermittent FAILs. I wonder whether there is a potentially unsafe
> > > > contruct at work (see below).
> > > Hm, no that does not fix it either.
> > >
> > > Eugene - can you have a closer look at this and see what might be going on?
> >
> > I ran 40x on each of my 11 test VMs and am unable to get a FAIL with this
> > patch.  I took a look at the test some more, but without a failure it's hard
> > to fix.
> >
> > Are you saying there is missing output (the motivating problem) or that
> > there is a timeout (I thought you may have said this, but I cannot find
> > where)?  Those would seem to be two separate problems, the latter being that
> > a trigger does not see 4 signals.
>
> Here is the issue:
>
> Diff against expected:
> --- test/unittest/usdt/tst.enable_pid.r 2025-06-08 00:17:54.789469056 -0400
> +++ /tmp/runtest.18085/test.out 2025-07-30 10:23:48.697293799 -0400
> @@ -22,8 +22,6 @@
> === epoch ===
> is not enabled
> is enabled
> -is not enabled
> -=== epoch ===
> ========== out 2
> is not enabled
> === epoch ===

I ran it 100 times, and got 26 failures.

OL9 - 5.15.0-304.171.4.1.el9uek.x86_64