From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx155.postini.com [74.125.245.155]) by kanga.kvack.org (Postfix) with SMTP id 758546B006C for ; Thu, 20 Dec 2012 19:49:38 -0500 (EST) Date: Fri, 21 Dec 2012 09:49:35 +0900 From: Minchan Kim Subject: Re: [PATCH] compaction: fix build error in CMA && !COMPACTION Message-ID: <20121221004935.GC2686@blaptop> References: <1355981130-2382-1-git-send-email-minchan@kernel.org> <20121220104707.GB10819@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20121220104707.GB10819@suse.de> Sender: owner-linux-mm@kvack.org List-ID: To: Mel Gorman Cc: Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Marek Szyprowski On Thu, Dec 20, 2012 at 10:47:07AM +0000, Mel Gorman wrote: > On Thu, Dec 20, 2012 at 02:25:30PM +0900, Minchan Kim wrote: > > isolate_freepages_block and isolate_migratepages_range is used for CMA > > as well as compaction so it breaks build for CONFIG_CMA && > > !CONFIG_COMPACTION. > > > > This patch fixes it. > > > > Cc: Mel Gorman > > Cc: Marek Szyprowski > > Signed-off-by: Minchan Kim > > --- > > mm/compaction.c | 26 ++++++++++++++++++++------ > > 1 file changed, 20 insertions(+), 6 deletions(-) > > > > diff --git a/mm/compaction.c b/mm/compaction.c > > index 5ad7f4f..70f4443 100644 > > --- a/mm/compaction.c > > +++ b/mm/compaction.c > > @@ -17,6 +17,21 @@ > > #include > > #include "internal.h" > > > > +#ifdef CONFIG_COMPACTION > > +static inline void count_compact_event(enum vm_event_item item) > > +{ > > + count_vm_event(item); > > +} > > + > > +static inline void count_compact_events(enum vm_event_item item, long delta) > > +{ > > + count_vm_events(item, delta); > > +} > > +#else > > +#define count_compact_event(item) > > +#define count_compact_events(item, delta) > > +#endif > > + > > That should be > > do {} while (0) > > otherwise a block like this > > if (foo) > count_compact_event(COMPACTFREE_SCANNED) > bar; > > will get parsed as > > if (foo) > bar; > > which is wrong. Indeed. > > Now that I look at the do {} while (0) thing it is also strictly speaking > wrong for count_vm_numa_events() too because it would do the wrong thing for If I noticed it, I should named it as count_vm_compact_events for the consistency. > > count_compact_events(COMPACTFREE_SCANNED, foo++); > > There happens to be no examples where we depend on such side-effects but Agreed. > I've taken a TODO item to fix it up in the New Year. Andrew picked up the patch with your fix. Please correct it for New Year's present. :) Thanks, Mel. > > -- > Mel Gorman > SUSE Labs > > -- > 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 -- Kind regards, Minchan Kim -- 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