diff mbox series

[v2,hmm,5/9] mm/hmm: remove the CONFIG_TRANSPARENT_HUGEPAGE #ifdef

Message ID 20200324011457.2817-6-jgg@ziepe.ca (mailing list archive)
State New, archived
Headers show
Series [v2,hmm,1/9] mm/hmm: remove pgmap checking for devmap pages | expand

Commit Message

Jason Gunthorpe March 24, 2020, 1:14 a.m. UTC 
From: Jason Gunthorpe <jgg@mellanox.com>

This code can be compiled when CONFIG_TRANSPARENT_HUGEPAGE is off, so
remove the ifdef.

The function is only ever called under

   if (pmd_devmap(pmd) || pmd_trans_huge(pmd))

Which is statically false if !CONFIG_TRANSPARENT_HUGEPAGE, so the compiler
reliably eliminates all of this code.

Reviewed-by: Ralph Campbell <rcampbell@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
---
 mm/hmm.c | 6 ------
 1 file changed, 6 deletions(-)

Comments

Christoph Hellwig March 24, 2020, 7:33 a.m. UTC | #1 
On Mon, Mar 23, 2020 at 10:14:53PM -0300, Jason Gunthorpe wrote:
> From: Jason Gunthorpe <jgg@mellanox.com>
> 
> This code can be compiled when CONFIG_TRANSPARENT_HUGEPAGE is off, so
> remove the ifdef.
> 
> The function is only ever called under
> 
>    if (pmd_devmap(pmd) || pmd_trans_huge(pmd))
> 
> Which is statically false if !CONFIG_TRANSPARENT_HUGEPAGE, so the compiler
> reliably eliminates all of this code.
> 
> Reviewed-by: Ralph Campbell <rcampbell@nvidia.com>
> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

Looks good,

Reviewed-by: Christoph Hellwig <hch@lst.de>
diff mbox series

Patch

diff --git a/mm/hmm.c b/mm/hmm.c
index 43d107a4d9dec6..f59e59fb303e95 100644
--- a/mm/hmm.c
+++ b/mm/hmm.c
@@ -198,7 +198,6 @@  static inline uint64_t pmd_to_hmm_pfn_flags(struct hmm_range *range, pmd_t pmd)
 				range->flags[HMM_PFN_VALID];
 }
 
-#ifdef CONFIG_TRANSPARENT_HUGEPAGE
 static int hmm_vma_handle_pmd(struct mm_walk *walk, unsigned long addr,
 		unsigned long end, uint64_t *pfns, pmd_t pmd)
 {
@@ -221,11 +220,6 @@  static int hmm_vma_handle_pmd(struct mm_walk *walk, unsigned long addr,
 	hmm_vma_walk->last = end;
 	return 0;
 }
-#else /* CONFIG_TRANSPARENT_HUGEPAGE */
-/* stub to allow the code below to compile */
-int hmm_vma_handle_pmd(struct mm_walk *walk, unsigned long addr,
-		unsigned long end, uint64_t *pfns, pmd_t pmd);
-#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 
 static inline bool hmm_is_device_private_entry(struct hmm_range *range,
 		swp_entry_t entry)