From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f72.google.com (mail-pa0-f72.google.com [209.85.220.72]) by kanga.kvack.org (Postfix) with ESMTP id 8BEC86B0005 for ; Sun, 10 Jul 2016 20:24:59 -0400 (EDT) Received: by mail-pa0-f72.google.com with SMTP id ib6so196079711pad.0 for ; Sun, 10 Jul 2016 17:24:59 -0700 (PDT) Received: from lgeamrelo12.lge.com (LGEAMRELO12.lge.com. [156.147.23.52]) by mx.google.com with ESMTP id c69si152036pfj.224.2016.07.10.17.24.58 for ; Sun, 10 Jul 2016 17:24:58 -0700 (PDT) Date: Mon, 11 Jul 2016 09:26:05 +0900 From: Minchan Kim Subject: Re: [PATCH] mm: migrate: Use bool instead of int for the return value of PageMovable Message-ID: <20160711002605.GD31817@bbox> References: <1468079704-5477-1-git-send-email-chengang@emindsoft.com.cn> MIME-Version: 1.0 In-Reply-To: <1468079704-5477-1-git-send-email-chengang@emindsoft.com.cn> Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline Sender: owner-linux-mm@kvack.org List-ID: To: chengang@emindsoft.com.cn Cc: akpm@linux-foundation.org, vbabka@suse.cz, mgorman@techsingularity.net, mhocko@suse.com, gi-oh.kim@profitbricks.com, iamjoonsoo.kim@lge.com, hillf.zj@alibaba-inc.com, rientjes@google.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Chen Gang On Sat, Jul 09, 2016 at 11:55:04PM +0800, chengang@emindsoft.com.cn wrote: > From: Chen Gang > > For pure bool function's return value, bool is a little better more or > less than int. > > And return boolean result directly, since 'if' statement is also for > boolean checking, and return boolean result, too. I just wanted to consistent with other PageXXX flags functions, PageAnon, PageMappingFlags which returns int rather than bool. Although I agree bool is natural, I want to be consistent with others rather than breaking at the moment. Maybe if you feel it's really helpful, you might be able to handle all of places I mentioned for better readability and keeping consistency. But I doubt it's worth. Thanks. > > Signed-off-by: Chen Gang > --- > include/linux/migrate.h | 4 ++-- > mm/compaction.c | 9 +++------ > 2 files changed, 5 insertions(+), 8 deletions(-) > > diff --git a/include/linux/migrate.h b/include/linux/migrate.h > index ae8d475..0e366f8 100644 > --- a/include/linux/migrate.h > +++ b/include/linux/migrate.h > @@ -72,11 +72,11 @@ static inline int migrate_huge_page_move_mapping(struct address_space *mapping, > #endif /* CONFIG_MIGRATION */ > > #ifdef CONFIG_COMPACTION > -extern int PageMovable(struct page *page); > +extern bool PageMovable(struct page *page); > extern void __SetPageMovable(struct page *page, struct address_space *mapping); > extern void __ClearPageMovable(struct page *page); > #else > -static inline int PageMovable(struct page *page) { return 0; }; > +static inline bool PageMovable(struct page *page) { return false; }; > static inline void __SetPageMovable(struct page *page, > struct address_space *mapping) > { > diff --git a/mm/compaction.c b/mm/compaction.c > index 0bd53fb..cfcfe88 100644 > --- a/mm/compaction.c > +++ b/mm/compaction.c > @@ -95,19 +95,16 @@ static inline bool migrate_async_suitable(int migratetype) > > #ifdef CONFIG_COMPACTION > > -int PageMovable(struct page *page) > +bool PageMovable(struct page *page) > { > struct address_space *mapping; > > VM_BUG_ON_PAGE(!PageLocked(page), page); > if (!__PageMovable(page)) > - return 0; > + return false; > > mapping = page_mapping(page); > - if (mapping && mapping->a_ops && mapping->a_ops->isolate_page) > - return 1; > - > - return 0; > + return mapping && mapping->a_ops && mapping->a_ops->isolate_page; > } > EXPORT_SYMBOL(PageMovable); > > -- > 1.9.3 > > -- > To unsubscribe, send a message with 'unsubscribe linux-mm' in > the body to majordomo@kvack.org. For more info on Linux MM, > see: http://www.linux-mm.org/ . > Don't email: email@kvack.org -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org