mm/gup_test: GUP_TEST depends on DEBUG_FS

Without DEBUG_FS, all the code in gup_benchmark becomes meaningless.
For sure kernel provides debugfs stub while DEBUG_FS is disabled, but
the point here is that GUP_TEST can do nothing without DEBUG_FS.

[song.bao.hua@hisilicon.com: add comment as a prompt to users as commented by John and Randy]
Link: https://lkml.kernel.org/r/20201108083732.15336-1-song.bao.hua@hisilicon.com
Link: https://lkml.kernel.org/r/20201104100552.20156-1-song.bao.hua@hisilicon.com
Signed-off-by: Barry Song <song.bao.hua@hisilicon.com>
Suggested-by: John Garry <john.garry@huawei.com>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/Kconfig b/mm/Kconfig
index 350f2e23a94ae3fbb3ad26a89c95e24509ccb079..5829d31649b99cb01c60503e40ff5db3616c0fe3 100644 (file)
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -823,6 +823,7 @@ config PERCPU_STATS
 
 config GUP_TEST
        bool "Enable infrastructure for get_user_pages()-related unit tests"
+       depends on DEBUG_FS
        help
          Provides /sys/kernel/debug/gup_test, which in turn provides a way
          to make ioctl calls that can launch kernel-based unit tests for
@@ -840,6 +841,9 @@ config GUP_TEST
 
          See tools/testing/selftests/vm/gup_test.c
 
+comment "GUP_TEST needs to have DEBUG_FS enabled"
+       depends on !GUP_TEST && !DEBUG_FS
+
 config GUP_GET_PTE_LOW_HIGH
        bool