Re: [PATCH] driver core: Fix test_async_driver_probe if NUMA is disabled

From: Alexander Duyck
Date: Wed Nov 27 2019 - 16:24:07 EST


On Wed, 2019-11-27 at 12:24 -0800, Guenter Roeck wrote:
> Since commit 57ea974fb871 ("driver core: Rewrite test_async_driver_probe
> to cover serialization and NUMA affinity"), running the test with NUMA
> disabled results in warning messages similar to the following.
>
> test_async_driver test_async_driver.12: NUMA node mismatch -1 != 0
>
> If CONFIG_NUMA=n, dev_to_node(dev) returns -1, and numa_node_id()
> returns 0. Both are widely used, so it appears risky to change return
> values. Augment the check with IS_ENABLED(CONFIG_NUMA) instead
> to fix the problem.
>
> Cc: Alexander Duyck <alexander.h.duyck@xxxxxxxxxxxxxxx>
> Fixes: 57ea974fb871 ("driver core: Rewrite test_async_driver_probe to cover serialization and NUMA affinity")
> Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx>
> ---
> drivers/base/test/test_async_driver_probe.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/base/test/test_async_driver_probe.c b/drivers/base/test/test_async_driver_probe.c
> index f4b1d8e54daf..3bb7beb127a9 100644
> --- a/drivers/base/test/test_async_driver_probe.c
> +++ b/drivers/base/test/test_async_driver_probe.c
> @@ -44,7 +44,8 @@ static int test_probe(struct platform_device *pdev)
> * performing an async init on that node.
> */
> if (dev->driver->probe_type == PROBE_PREFER_ASYNCHRONOUS) {
> - if (dev_to_node(dev) != numa_node_id()) {
> + if (IS_ENABLED(CONFIG_NUMA) &&
> + dev_to_node(dev) != numa_node_id()) {
> dev_warn(dev, "NUMA node mismatch %d != %d\n",
> dev_to_node(dev), numa_node_id());
> atomic_inc(&warnings);

I'm not sure that is really the correct fix. It might be better to test it
against NUMA_NO_NODE and then if it is not that make sure that it matches
the node ID. Adding the check against NUMA_NO_NODE would resolve the issue
for cases where the device might be assigned to multiple NUMA nodes.