Re: [PATCH] resource, kunit: stop selecting GET_FREE_REGION

[Bradley Morgan]

On 26 September 2026 01:26:51 BST, Karl Mehltretter
<kmehltretter@xxxxxxxxx> wrote:
>RESOURCE_KUNIT_TEST selects GET_FREE_REGION even when no other option
>needs it. Remove the selection to follow the dependency rule in
>Documentation/dev-tools/kunit/style.rst.
>
>Skip resource_test_region_intersects() when GET_FREE_REGION is disabled.
>GET_FREE_REGION has no prompt, so configurations without a production
>consumer cannot enable it. Most configurations will therefore skip this
>case; this is intentional. The union and intersection tests remain
>available.
>
>Since kunit_skip() does not return, the compiler drops the reference to
>the unavailable alloc_free_mem_region(), as in the CONFIG_OF_ADDRESS
>check in drivers/of/of_test.c.
>
>Fixes: 99185c10d5d9 ("resource, kunit: add test case for region_intersects()")
>Assisted-by: LLM
>Signed-off-by: Karl Mehltretter <kmehltretter@xxxxxxxxx>
>---
>Validation:
>- Clang 22 and GCC 13 ARM builds pass with RESOURCE_KUNIT_TEST=y and =m
>  while GET_FREE_REGION=n. The built-in vmlinux images have no
>  alloc_free_mem_region symbol, and the modules have no undefined
>  reference to it.
>- Clang 22 x86_64 builds and QEMU 11.0.2 runs pass. GET_FREE_REGION=n
>  reports two passes and resource_test_region_intersects as SKIP;
>  DEVICE_PRIVATE=y enables GET_FREE_REGION and reports three passes.
>
> kernel/resource_kunit.c | 3 +++
> lib/Kconfig.debug       | 1 -
> 2 files changed, 3 insertions(+), 1 deletion(-)
>
>diff --git a/kernel/resource_kunit.c b/kernel/resource_kunit.c
>index 42785796f1db..9eeb2b1a85c0 100644
>--- a/kernel/resource_kunit.c
>+++ b/kernel/resource_kunit.c
>@@ -225,6 +225,9 @@ static void resource_test_region_intersects(struct kunit *test)
> 	struct resource *parent;
> 	resource_size_t start;
> 
>+	if (!IS_ENABLED(CONFIG_GET_FREE_REGION))
>+		kunit_skip(test, "CONFIG_GET_FREE_REGION is disabled");

Interesting.

Reviewed-by: Bradley Morgan <brads@xxxxxxxxxxxxxx>

Tested on Power10 (PowerPC), in courtesy of osuosl:

Tested-by: Bradley Morgan <brads@xxxxxxxxxxxxxx> # Power10


>+
> 	/* Find an iomem_resource hole to hold test resources */
> 	parent = alloc_free_mem_region(&iomem_resource, RES_TEST_TOTAL_SIZE, SZ_1M,
> 				       "test resources");
>diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
>index 134b15a44625..e7c5d5b5870f 100644
>--- a/lib/Kconfig.debug
>+++ b/lib/Kconfig.debug
>@@ -2776,7 +2776,6 @@ config RESOURCE_KUNIT_TEST
> 	tristate "KUnit test for resource API" if !KUNIT_ALL_TESTS
> 	depends on KUNIT
> 	default KUNIT_ALL_TESTS
>-	select GET_FREE_REGION
> 	help
> 	  This builds the resource API unit test.
> 	  Tests the logic of API provided by resource.c and ioport.h.
>
>base-commit: aa98230e410f0ed212b6788c46b1e4d49e0ff7ca
>

--- Thanks!
"I'm not a very positive person" - Linus torvalds