[RESEND PATCH 2/2] arm64: make WANT_HUGE_PMD_SHARE depends on HUGETLB_PAGE

On 2016/12/16 20:35, Will Deacon wrote:

On Fri, Dec 16, 2016 at 05:10:05PM +0800, zhong jiang wrote:

quoted

On 2016/12/14 22:19, zhongjiang wrote:

quoted

From: zhong jiang <redacted>

when HUGETLB_PAGE is disable, WANT_HUGE_PMD_SHARE contains the
fuctions should not be use. therefore, we add the dependency.

Signed-off-by: zhong jiang <redacted>
---
 arch/arm64/Kconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 969ef88..694ca73 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig

@@ -640,6 +640,7 @@ config SYS_SUPPORTS_HUGETLBFS
 
 config ARCH_WANT_HUGE_PMD_SHARE
 	def_bool y if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36)
+	depends on HUGETLB_PAGE
 
 config ARCH_HAS_CACHE_LINE_SIZE
 	def_bool y

Hi,
      I still think it is a issue. Perhaps above changelog is unclear.  Further explain is as follows.
 when hugetlb_pages is disable and arch_want_huge_pmd_share is enable,   we maybe call
 huge_pmd_sahre in hugetlbpage.c, but the function actually is not definition as it is not
 exported.  is it right ??

The only users of ARCH_WANT_HUGE_PMD_SHARE on arm64 are:

arch/arm64/mm/hugetlbpage.c:            if (IS_ENABLED(CONFIG_ARCH_WANT_HUGE_PMD_SHARE) &&

  yes

mm/hugetlb.c:#ifdef CONFIG_ARCH_WANT_HUGE_PMD_SHARE
mm/hugetlb.c:#else /* !CONFIG_ARCH_WANT_HUGE_PMD_SHARE */
mm/hugetlb.c:#endif /* CONFIG_ARCH_WANT_HUGE_PMD_SHARE */

and neither of those files are compiled if !HUGETLB_PAGE.

  Indeed, but  The only users maybe use it  if !HUGETLB_PAGE. 
  because  include/linux/hugetlb.h  can not export the reference if !HUGETLB_PAGE.
  IOW,  the function is not definition.  

  is it right ? or I miss the key point.

Are you actually seeing a problem here?

  I review the code and find the issue.

 Thanks
 zhongjiang

Will

.