Re: [PATCH] test/cxl-xor-region.sh: remove redundant waitting

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

On Wed, May 14, 2025 at 07:20:03PM +0800, ruansy.fnst wrote:
> From: Ruan Shiyang <ruansy.fnst@fujitsu.com>
> 
> Now that cxl_wait_probe() has been added[1] to wait for udev queue
> empty, the `udevadm settle` here is no longer necessary.
> 
> [1] b231603 cxl/lib: Add cxl_wait_probe()
> 
> Signed-off-by: Ruan Shiyang <ruansy.fnst@fujitsu.com>

Reviewed-by: Alison Schofield <alison.schofield@intel.com>

Hi Ruan, It looks like I snuck this one in right before Dan introduced
udevadm settle and cleaned up all the usages. I'll take this patch as
is. The next time you patch ndctl, do these:

[PATCH] --> [ndctl PATCH]
Send to nvdimm@lists.linux.dev and 'cc linux-cxl@vger.kernel.org
if it's CXL related like this one.

I suggest you resend this udev question in a new email to linux-cxl
list to draw attention. 

Thanks for the patch!

> 
> ===
> Question to Dan:
> 
> I understand how cxl_wait_probe() work, but I have some questions about
> the motivation of adding this function:  Firstly, is it function added
> for simply waiting for new added CXL device been ready before cxl
> command does the actual work?  Just for replacing `udevadm settle`'s
> work?
> 
> Now I am facing a problem that cxl command takes a long time to complete
> when I run it in a udev rule(do some configuration when CXL memdev is
> added).  I found it is caused by this function: waitting for udev
> queue's endding but itself is in the queue.  The cxl_wait_probe()
> function does not seem to allow me to do that.  So, the 2nd question is:
> is it against the spec to run cxl command in a udev rule?
> ====
> ---
>  test/cxl-xor-region.sh | 1 -
>  1 file changed, 1 deletion(-)
> 
> diff --git a/test/cxl-xor-region.sh b/test/cxl-xor-region.sh
> index b9e1d79..fb4f9a0 100644
> --- a/test/cxl-xor-region.sh
> +++ b/test/cxl-xor-region.sh
> @@ -14,7 +14,6 @@ check_prereq "jq"
>  
>  modprobe -r cxl_test
>  modprobe cxl_test interleave_arithmetic=1
> -udevadm settle
>  rc=1
>  
>  # THEORY OF OPERATION: Create x1,2,3,4 regions to exercise the XOR math
> -- 
> 2.43.0
> 
>