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authorPeter Xu <peterx@redhat.com>2022-08-11 12:13:26 -0400
committerAndrew Morton <akpm@linux-foundation.org>2022-09-26 19:46:04 -0700
commiteba4d770efc86a3710e36b828190858abfa3bb74 (patch)
tree25c46a8bc2a4c350affe839bdd6f5809aa794217 /include/linux/swapops.h
parentmm/x86: use SWP_TYPE_BITS in 3-level swap macros (diff)
downloadlinux-dev-eba4d770efc86a3710e36b828190858abfa3bb74.tar.xz
linux-dev-eba4d770efc86a3710e36b828190858abfa3bb74.zip
mm/swap: comment all the ifdef in swapops.h
swapops.h contains quite a few layers of ifdef, some of the "else" and "endif" doesn't get proper comment on the macro so it's hard to follow on what are they referring to. Add the comments. Link: https://lkml.kernel.org/r/20220811161331.37055-3-peterx@redhat.com Signed-off-by: Peter Xu <peterx@redhat.com> Suggested-by: Nadav Amit <nadav.amit@gmail.com> Reviewed-by: Huang Ying <ying.huang@intel.com> Reviewed-by: Alistair Popple <apopple@nvidia.com> Cc: Andi Kleen <andi.kleen@intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: David Hildenbrand <david@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: "Kirill A . Shutemov" <kirill@shutemov.name> Cc: Minchan Kim <minchan@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Dave Hansen <dave.hansen@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'include/linux/swapops.h')
-rw-r--r--include/linux/swapops.h16
1 files changed, 8 insertions, 8 deletions
diff --git a/include/linux/swapops.h b/include/linux/swapops.h
index 88825d1785d2..7d1b74046520 100644
--- a/include/linux/swapops.h
+++ b/include/linux/swapops.h
@@ -247,8 +247,8 @@ extern void migration_entry_wait(struct mm_struct *mm, pmd_t *pmd,
#ifdef CONFIG_HUGETLB_PAGE
extern void __migration_entry_wait_huge(pte_t *ptep, spinlock_t *ptl);
extern void migration_entry_wait_huge(struct vm_area_struct *vma, pte_t *pte);
-#endif
-#else
+#endif /* CONFIG_HUGETLB_PAGE */
+#else /* CONFIG_MIGRATION */
static inline swp_entry_t make_readable_migration_entry(pgoff_t offset)
{
return swp_entry(0, 0);
@@ -276,7 +276,7 @@ static inline void migration_entry_wait(struct mm_struct *mm, pmd_t *pmd,
#ifdef CONFIG_HUGETLB_PAGE
static inline void __migration_entry_wait_huge(pte_t *ptep, spinlock_t *ptl) { }
static inline void migration_entry_wait_huge(struct vm_area_struct *vma, pte_t *pte) { }
-#endif
+#endif /* CONFIG_HUGETLB_PAGE */
static inline int is_writable_migration_entry(swp_entry_t entry)
{
return 0;
@@ -286,7 +286,7 @@ static inline int is_readable_migration_entry(swp_entry_t entry)
return 0;
}
-#endif
+#endif /* CONFIG_MIGRATION */
typedef unsigned long pte_marker;
@@ -426,7 +426,7 @@ static inline int is_pmd_migration_entry(pmd_t pmd)
{
return is_swap_pmd(pmd) && is_migration_entry(pmd_to_swp_entry(pmd));
}
-#else
+#else /* CONFIG_ARCH_ENABLE_THP_MIGRATION */
static inline int set_pmd_migration_entry(struct page_vma_mapped_walk *pvmw,
struct page *page)
{
@@ -455,7 +455,7 @@ static inline int is_pmd_migration_entry(pmd_t pmd)
{
return 0;
}
-#endif
+#endif /* CONFIG_ARCH_ENABLE_THP_MIGRATION */
#ifdef CONFIG_MEMORY_FAILURE
@@ -490,7 +490,7 @@ static inline void num_poisoned_pages_sub(long i)
atomic_long_sub(i, &num_poisoned_pages);
}
-#else
+#else /* CONFIG_MEMORY_FAILURE */
static inline swp_entry_t make_hwpoison_entry(struct page *page)
{
@@ -509,7 +509,7 @@ static inline void num_poisoned_pages_inc(void)
static inline void num_poisoned_pages_sub(long i)
{
}
-#endif
+#endif /* CONFIG_MEMORY_FAILURE */
static inline int non_swap_entry(swp_entry_t entry)
{