selftests/mm: remove flaky header check

Commit 96ed62ea0298 ("mm: page_frag: fix a compile error when kernel is
not compiled") introduced a check to avoid attempting to build the
page_frag module if <linux/page_frag_cache.h> is missing.

Unfortunately this check only works if KDIR points to /lib/modules/...  or
an in-tree kernel build.  It always fails if KDIR points to an out-of-tree
build (i.e.  when the kernel was built with O=...  make) because only
generated headers are present under $KDIR/include/ in that case.

A recent commit switched KDIR to default to the kernel's build directory,
so that check is no longer justified.

Link: https://lkml.kernel.org/r/20260122170224.4056513-3-kevin.brodsky@arm.com
Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Yunsheng Lin <linyunsheng@huawei.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: SeongJae Park <sj@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Usama Anjum <Usama.Anjum@arm.com>
Cc: wang lian <lianux.mm@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/tools/testing/selftests/mm/Makefile b/tools/testing/selftests/mm/Makefile
index bb93101e339e8932d5cf4956c82cce1d8805001e..4e5c8a330a0cc60e0f09096ccc4147738226efe6 100644 (file)
--- a/tools/testing/selftests/mm/Makefile
+++ b/tools/testing/selftests/mm/Makefile
@@ -46,12 +46,8 @@ CFLAGS += -U_FORTIFY_SOURCE
 
 KDIR ?= $(if $(O),$(O),$(realpath ../../../..))
 ifneq (,$(wildcard $(KDIR)/Module.symvers))
-ifneq (,$(wildcard $(KDIR)/include/linux/page_frag_cache.h))
 TEST_GEN_MODS_DIR := page_frag
 else
-PAGE_FRAG_WARNING = "missing page_frag_cache.h, please use a newer kernel"
-endif
-else
 PAGE_FRAG_WARNING = "missing Module.symvers, please have the kernel built first"
 endif