Re: [PATCH ndctl 3/3] test/cxl-security.sh: avoid intermittent failures due to sasync probe

["Verma, Vishal L" <vishal.l.verma@intel.com>]

On Tue, 2023-02-21 at 09:22 -0800, Alison Schofield wrote:
> On Fri, Feb 17, 2023 at 05:40:24PM -0700, Vishal Verma wrote:
> > This test failed intermittently because the ndctl-list operation right
> > after a 'modprobe cxl_test' could race the actual nmem devices getting
> > loaded.
> > 
> > Since CXL device probes are asynchronous, and cxl_acpi might've kicked
> > off a cxl_bus_rescan(), a cxl_flush() (via cxl_wait_probe()) can ensure
> > everything is loaded.
> > 
> > Add a plain cxl-list right after the modprobe to allow for a flush/wait
> > cycle.
> 
> Is this the preferred method to 'settle', instead of udevadm settle?

Generally, no. Usually cxl tests would use cxl-cli commands, which now
have the necessary waits via cxl_wait_probe(), so even a 'udevadm
settle' shouldn't be needed.

In this case, the first thing we run is ndctl list, which waits for
nvdimm things to 'settle', but we were racing with cxl_test coming up,
which it (ndctl) knows nothing about.

> 
> > 
> > Cc: Dave Jiang <dave.jiang@intel.com>
> > Suggested-by: Dan Williams <dan.j.williams@intel.com>
> > Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
> > ---
> >  test/security.sh | 1 +
> >  1 file changed, 1 insertion(+)
> > 
> > diff --git a/test/security.sh b/test/security.sh
> > index 04f630e..fb04aa6 100755
> > --- a/test/security.sh
> > +++ b/test/security.sh
> > @@ -225,6 +225,7 @@ if [ "$uid" -ne 0 ]; then
> >  fi
> >  
> >  modprobe "$KMOD_TEST"
> > +cxl list
> >  setup
> >  check_prereq "keyctl"
> >  rc=1
> > 
> > -- 
> > 2.39.1
> > 
> >