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

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

[Alison Schofield]

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>
---
 test/cxl-sanitize.sh | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/test/cxl-sanitize.sh b/test/cxl-sanitize.sh
index 9c161014ccb7..d1ed598f3663 100644
--- a/test/cxl-sanitize.sh
+++ b/test/cxl-sanitize.sh
@@ -68,6 +68,9 @@ done
 set_timeout $inactive 3000
 start=$SECONDS
 echo 1 > /sys/bus/cxl/devices/${inactive}/security/sanitize &
+
+# Allow background sanitize to start before wait-sanitize can observe it
+sleep 1
 "$CXL" wait-sanitize $inactive || err $LINENO
 ((SECONDS > start + 2)) || err $LINENO
 
-- 
2.37.3

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

[Dave Jiang]

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>

> ---
>  test/cxl-sanitize.sh | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/test/cxl-sanitize.sh b/test/cxl-sanitize.sh
> index 9c161014ccb7..d1ed598f3663 100644
> --- a/test/cxl-sanitize.sh
> +++ b/test/cxl-sanitize.sh
> @@ -68,6 +68,9 @@ done
>  set_timeout $inactive 3000
>  start=$SECONDS
>  echo 1 > /sys/bus/cxl/devices/${inactive}/security/sanitize &
> +
> +# Allow background sanitize to start before wait-sanitize can observe it
> +sleep 1
>  "$CXL" wait-sanitize $inactive || err $LINENO
>  ((SECONDS > start + 2)) || err $LINENO
>  

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

[Alison Schofield]

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