Re: [ndctl PATCH] test/cxl-sanitize: avoid sanitize submit/wait race

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

On Thu, Apr 30, 2026 at 09:31:42AM -0700, Dave Jiang wrote:
> 
> 
> On 4/29/26 7:18 PM, Alison Schofield wrote:
> > This test verifies that wait-sanitize blocks for the programmed
> > timeout after issuing sanitize on an inactive memdev.
> > 
> > The sanitize request is issued in the background and wait-sanitize
> > is called immediately after. In cxl_test, sanitize completes
> > asynchronously via delayed work, and the sysfs write does not block.
> > This creates a race where wait-sanitize may run before sanitize is
> > observed and return immediately.
> > 
> > This test has been reliable since its introduction, but recently
> > started failing consistently in one environment, suggesting a
> > timing sensitivity. It fails here:
> > 
> >   ((SECONDS > start + 2)) || err $LINENO
> > 
> > Add a short delay after backgrounding the sanitize write to make
> > sure that wait-sanitize can observe the in-progress operation.
> > 
> > A sysfs-based synchronization was considered, but no in-progress
> > state is exposed to user space.
> > 
> > Signed-off-by: Alison Schofield <alison.schofield@intel.com>
> 
> Looks reasonable
> 
> Reviewed-by: Dave Jiang <dave.jiang@intel.com>

Thanks!
Applied to: https://github.com/pmem/ndctl/tree/pending