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mm: make rmap_walk() return void
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There is no user of the return value from rmap_walk() and friends so
this patch makes them void-returning functions.

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Minchan Kim <[email protected]>
Cc: Anshuman Khandual <[email protected]>
Cc: Hillf Danton <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Kirill A. Shutemov <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Naoya Horiguchi <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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@minchank @torvalds
minchank authored and torvalds committed May 3, 2017
1 parent 666e5a4 commit 1df631a
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Showing 4 changed files with 23 additions and 34 deletions.
5 changes: 2 additions & 3 deletions include/linux/ksm.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -61,7 +61,7 @@ static inline void set_page_stable_node(struct page *page,
struct page *ksm_might_need_to_copy(struct page *page,
struct vm_area_struct *vma, unsigned long address);

int rmap_walk_ksm(struct page *page, struct rmap_walk_control *rwc);
void rmap_walk_ksm(struct page *page, struct rmap_walk_control *rwc);
void ksm_migrate_page(struct page *newpage, struct page *oldpage);

#else /* !CONFIG_KSM */
Expand Down Expand Up @@ -94,10 +94,9 @@ static inline int page_referenced_ksm(struct page *page,
return 0;
}

static inline int rmap_walk_ksm(struct page *page,
static inline void rmap_walk_ksm(struct page *page,
struct rmap_walk_control *rwc)
{
return 0;
}

static inline void ksm_migrate_page(struct page *newpage, struct page *oldpage)
Expand Down
4 changes: 2 additions & 2 deletions include/linux/rmap.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -264,8 +264,8 @@ struct rmap_walk_control {
bool (*invalid_vma)(struct vm_area_struct *vma, void *arg);
};

int rmap_walk(struct page *page, struct rmap_walk_control *rwc);
int rmap_walk_locked(struct page *page, struct rmap_walk_control *rwc);
void rmap_walk(struct page *page, struct rmap_walk_control *rwc);
void rmap_walk_locked(struct page *page, struct rmap_walk_control *rwc);

#else /* !CONFIG_MMU */

Expand Down
16 changes: 6 additions & 10 deletions mm/ksm.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1933,11 +1933,10 @@ struct page *ksm_might_need_to_copy(struct page *page,
return new_page;
}

int rmap_walk_ksm(struct page *page, struct rmap_walk_control *rwc)
void rmap_walk_ksm(struct page *page, struct rmap_walk_control *rwc)
{
struct stable_node *stable_node;
struct rmap_item *rmap_item;
int ret = SWAP_AGAIN;
int search_new_forks = 0;

VM_BUG_ON_PAGE(!PageKsm(page), page);
Expand All @@ -1950,7 +1949,7 @@ int rmap_walk_ksm(struct page *page, struct rmap_walk_control *rwc)

stable_node = page_stable_node(page);
if (!stable_node)
return ret;
return;
again:
hlist_for_each_entry(rmap_item, &stable_node->hlist, hlist) {
struct anon_vma *anon_vma = rmap_item->anon_vma;
Expand Down Expand Up @@ -1978,23 +1977,20 @@ int rmap_walk_ksm(struct page *page, struct rmap_walk_control *rwc)
if (rwc->invalid_vma && rwc->invalid_vma(vma, rwc->arg))
continue;

ret = rwc->rmap_one(page, vma,
rmap_item->address, rwc->arg);
if (ret != SWAP_AGAIN) {
if (SWAP_AGAIN != rwc->rmap_one(page, vma,
rmap_item->address, rwc->arg)) {
anon_vma_unlock_read(anon_vma);
goto out;
return;
}
if (rwc->done && rwc->done(page)) {
anon_vma_unlock_read(anon_vma);
goto out;
return;
}
}
anon_vma_unlock_read(anon_vma);
}
if (!search_new_forks++)
goto again;
out:
return ret;
}

#ifdef CONFIG_MIGRATION
Expand Down
32 changes: 13 additions & 19 deletions mm/rmap.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1607,13 +1607,12 @@ static struct anon_vma *rmap_walk_anon_lock(struct page *page,
* vm_flags for that VMA. That should be OK, because that vma shouldn't be
* LOCKED.
*/
static int rmap_walk_anon(struct page *page, struct rmap_walk_control *rwc,
static void rmap_walk_anon(struct page *page, struct rmap_walk_control *rwc,
bool locked)
{
struct anon_vma *anon_vma;
pgoff_t pgoff_start, pgoff_end;
struct anon_vma_chain *avc;
int ret = SWAP_AGAIN;

if (locked) {
anon_vma = page_anon_vma(page);
Expand All @@ -1623,7 +1622,7 @@ static int rmap_walk_anon(struct page *page, struct rmap_walk_control *rwc,
anon_vma = rmap_walk_anon_lock(page, rwc);
}
if (!anon_vma)
return ret;
return;

pgoff_start = page_to_pgoff(page);
pgoff_end = pgoff_start + hpage_nr_pages(page) - 1;
Expand All @@ -1637,16 +1636,14 @@ static int rmap_walk_anon(struct page *page, struct rmap_walk_control *rwc,
if (rwc->invalid_vma && rwc->invalid_vma(vma, rwc->arg))
continue;

ret = rwc->rmap_one(page, vma, address, rwc->arg);
if (ret != SWAP_AGAIN)
if (SWAP_AGAIN != rwc->rmap_one(page, vma, address, rwc->arg))
break;
if (rwc->done && rwc->done(page))
break;
}

if (!locked)
anon_vma_unlock_read(anon_vma);
return ret;
}

/*
Expand All @@ -1662,13 +1659,12 @@ static int rmap_walk_anon(struct page *page, struct rmap_walk_control *rwc,
* vm_flags for that VMA. That should be OK, because that vma shouldn't be
* LOCKED.
*/
static int rmap_walk_file(struct page *page, struct rmap_walk_control *rwc,
static void rmap_walk_file(struct page *page, struct rmap_walk_control *rwc,
bool locked)
{
struct address_space *mapping = page_mapping(page);
pgoff_t pgoff_start, pgoff_end;
struct vm_area_struct *vma;
int ret = SWAP_AGAIN;

/*
* The page lock not only makes sure that page->mapping cannot
Expand All @@ -1679,7 +1675,7 @@ static int rmap_walk_file(struct page *page, struct rmap_walk_control *rwc,
VM_BUG_ON_PAGE(!PageLocked(page), page);

if (!mapping)
return ret;
return;

pgoff_start = page_to_pgoff(page);
pgoff_end = pgoff_start + hpage_nr_pages(page) - 1;
Expand All @@ -1694,8 +1690,7 @@ static int rmap_walk_file(struct page *page, struct rmap_walk_control *rwc,
if (rwc->invalid_vma && rwc->invalid_vma(vma, rwc->arg))
continue;

ret = rwc->rmap_one(page, vma, address, rwc->arg);
if (ret != SWAP_AGAIN)
if (SWAP_AGAIN != rwc->rmap_one(page, vma, address, rwc->arg))
goto done;
if (rwc->done && rwc->done(page))
goto done;
Expand All @@ -1704,28 +1699,27 @@ static int rmap_walk_file(struct page *page, struct rmap_walk_control *rwc,
done:
if (!locked)
i_mmap_unlock_read(mapping);
return ret;
}

int rmap_walk(struct page *page, struct rmap_walk_control *rwc)
void rmap_walk(struct page *page, struct rmap_walk_control *rwc)
{
if (unlikely(PageKsm(page)))
return rmap_walk_ksm(page, rwc);
rmap_walk_ksm(page, rwc);
else if (PageAnon(page))
return rmap_walk_anon(page, rwc, false);
rmap_walk_anon(page, rwc, false);
else
return rmap_walk_file(page, rwc, false);
rmap_walk_file(page, rwc, false);
}

/* Like rmap_walk, but caller holds relevant rmap lock */
int rmap_walk_locked(struct page *page, struct rmap_walk_control *rwc)
void rmap_walk_locked(struct page *page, struct rmap_walk_control *rwc)
{
/* no ksm support for now */
VM_BUG_ON_PAGE(PageKsm(page), page);
if (PageAnon(page))
return rmap_walk_anon(page, rwc, true);
rmap_walk_anon(page, rwc, true);
else
return rmap_walk_file(page, rwc, true);
rmap_walk_file(page, rwc, true);
}

#ifdef CONFIG_HUGETLB_PAGE
Expand Down

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