Commit 2948be5a authored May 03, 2017 by Minchan Kim Committed by Linus Torvalds May 03, 2017

mm: do not use double negation for testing page flags

With the discussion[1], I found it seems there are every PageFlags
functions return bool at this moment so we don't need double negation
any more.  Although it's not a problem to keep it, it makes future users
confused to use double negation for them, too.

Remove such possibility.

[1] https://marc.info/?l=linux-kernel&m=148881578820434

Frankly sepaking, I like every PageFlags to return bool instead of int.
It will make it clear.  AFAIR, Chen Gang had tried it but don't know why
it was not merged at that time.

http://lkml.kernel.org/r/1469336184-1904-1-git-send-email-chengang@emindsoft.com.cn

Link: http://lkml.kernel.org/r/1488868597-32222-1-git-send-email-minchan@kernel.org


Signed-off-by: Minchan Kim <minchan@kernel.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Chen Gang <gang.chen.5i5j@gmail.com>
Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 056b9d8a

mm/khugepaged.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -548,7 +548,7 @@ static int __collapse_huge_page_isolate(struct vm_area_struct *vma,
		* The page must only be referenced by the scanned process
		* and page swap cache.
		*/
		if (page_count(page) != 1 + !!PageSwapCache(page)) {
		if (page_count(page) != 1 + PageSwapCache(page)) {
		unlock_page(page);
		result = SCAN_PAGE_COUNT;
		goto out;
		@@ -1181,7 +1181,7 @@ static int khugepaged_scan_pmd(struct mm_struct *mm,
		* The page must only be referenced by the scanned process
		* and page swap cache.
		*/
		if (page_count(page) != 1 + !!PageSwapCache(page)) {
		if (page_count(page) != 1 + PageSwapCache(page)) {
		result = SCAN_PAGE_COUNT;
		goto out_unmap;
		}

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