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

[Alison Schofield <alison.schofield@intel.com>]

On Tue, Feb 21, 2023 at 10:13:16AM -0800, Vishal Verma wrote:
> 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.

OK - I'll stop doing the udevadm settle, since what I'm doing is pure
'cxl' and modprobe is always followed by cxl-cli commands. 

> 
> >
> > >
> > > 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
> > >
> > >
>