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authorMinchan Kim <minchan@kernel.org>2017-05-03 14:54:10 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2017-05-03 15:52:10 -0700
commit192d7232569ab61ded40c8be691b12832bc6bcd1 (patch)
treeed7fbaa077751989b488be430dbf58cf5af30b15
parent22ffb33f4620b502799877d4186502bfe20621ea (diff)
mm: make try_to_munlock() return void
try_to_munlock returns SWAP_MLOCK if the one of VMAs mapped the page has VM_LOCKED flag. In that time, VM set PG_mlocked to the page if the page is not pte-mapped THP which cannot be mlocked, either. With that, __munlock_isolated_page can use PageMlocked to check whether try_to_munlock is successful or not without relying on try_to_munlock's retval. It helps to make try_to_unmap/try_to_unmap_one simple with upcoming patches. [minchan@kernel.org: remove PG_Mlocked VM_BUG_ON check] Link: http://lkml.kernel.org/r/20170411025615.GA6545@bbox Link: http://lkml.kernel.org/r/1489555493-14659-5-git-send-email-minchan@kernel.org Signed-off-by: Minchan Kim <minchan@kernel.org> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--include/linux/rmap.h2
-rw-r--r--mm/mlock.c6
-rw-r--r--mm/rmap.c16
3 files changed, 7 insertions, 17 deletions
diff --git a/include/linux/rmap.h b/include/linux/rmap.h
index b556eefa62bc..1b0cd4cf68e3 100644
--- a/include/linux/rmap.h
+++ b/include/linux/rmap.h
@@ -235,7 +235,7 @@ int page_mkclean(struct page *);
* called in munlock()/munmap() path to check for other vmas holding
* the page mlocked.
*/
-int try_to_munlock(struct page *);
+void try_to_munlock(struct page *);
void remove_migration_ptes(struct page *old, struct page *new, bool locked);
diff --git a/mm/mlock.c b/mm/mlock.c
index 0dd9ca18e19e..c483c5c20b4b 100644
--- a/mm/mlock.c
+++ b/mm/mlock.c
@@ -123,17 +123,15 @@ static bool __munlock_isolate_lru_page(struct page *page, bool getpage)
*/
static void __munlock_isolated_page(struct page *page)
{
- int ret = SWAP_AGAIN;
-
/*
* Optimization: if the page was mapped just once, that's our mapping
* and we don't need to check all the other vmas.
*/
if (page_mapcount(page) > 1)
- ret = try_to_munlock(page);
+ try_to_munlock(page);
/* Did try_to_unlock() succeed or punt? */
- if (ret != SWAP_MLOCK)
+ if (!PageMlocked(page))
count_vm_event(UNEVICTABLE_PGMUNLOCKED);
putback_lru_page(page);
diff --git a/mm/rmap.c b/mm/rmap.c
index dfe40557ea29..171db511aa8c 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -1552,18 +1552,10 @@ static int page_not_mapped(struct page *page)
* Called from munlock code. Checks all of the VMAs mapping the page
* to make sure nobody else has this page mlocked. The page will be
* returned with PG_mlocked cleared if no other vmas have it mlocked.
- *
- * Return values are:
- *
- * SWAP_AGAIN - no vma is holding page mlocked, or,
- * SWAP_AGAIN - page mapped in mlocked vma -- couldn't acquire mmap sem
- * SWAP_FAIL - page cannot be located at present
- * SWAP_MLOCK - page is now mlocked.
*/
-int try_to_munlock(struct page *page)
-{
- int ret;
+void try_to_munlock(struct page *page)
+{
struct rmap_walk_control rwc = {
.rmap_one = try_to_unmap_one,
.arg = (void *)TTU_MUNLOCK,
@@ -1573,9 +1565,9 @@ int try_to_munlock(struct page *page)
};
VM_BUG_ON_PAGE(!PageLocked(page) || PageLRU(page), page);
+ VM_BUG_ON_PAGE(PageCompound(page) && PageDoubleMap(page), page);
- ret = rmap_walk(page, &rwc);
- return ret;
+ rmap_walk(page, &rwc);
}
void __put_anon_vma(struct anon_vma *anon_vma)