From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx126.postini.com [74.125.245.126]) by kanga.kvack.org (Postfix) with SMTP id 043ED6B0069 for ; Thu, 20 Dec 2012 05:47:12 -0500 (EST) Date: Thu, 20 Dec 2012 10:47:07 +0000 From: Mel Gorman Subject: Re: [PATCH] compaction: fix build error in CMA && !COMPACTION Message-ID: <20121220104707.GB10819@suse.de> References: <1355981130-2382-1-git-send-email-minchan@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <1355981130-2382-1-git-send-email-minchan@kernel.org> Sender: owner-linux-mm@kvack.org List-ID: To: Minchan Kim Cc: Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Marek Szyprowski 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. 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 count_compact_events(COMPACTFREE_SCANNED, foo++); There happens to be no examples where we depend on such side-effects but I've taken a TODO item to fix it up in the New Year. -- 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