From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chao Yu Subject: Re: [PATCH 08/11] f2fs: fix wrong condition for unlikely Date: Wed, 30 Jul 2014 20:58:37 +0800 Message-ID: <00f401cfabf6$14f52b70$3edf8250$@samsung.com> References: <1406328445-63707-1-git-send-email-jaegeuk@kernel.org> <1406328445-63707-8-git-send-email-jaegeuk@kernel.org> <009901cfab97$f2981be0$d7c853a0$@samsung.com> <20140730031820.GC99885@jaegeuk-mac02> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from sog-mx-1.v43.ch3.sourceforge.com ([172.29.43.191] helo=mx.sourceforge.net) by sfs-ml-4.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1XCTTe-0007Kt-7n for linux-f2fs-devel@lists.sourceforge.net; Wed, 30 Jul 2014 12:59:30 +0000 Received: from mailout2.samsung.com ([203.254.224.25]) by sog-mx-1.v43.ch3.sourceforge.com with esmtps (TLSv1:RC4-MD5:128) (Exim 4.76) id 1XCTTb-00034B-Ra for linux-f2fs-devel@lists.sourceforge.net; Wed, 30 Jul 2014 12:59:30 +0000 Received: from epcpsbgm2.samsung.com (epcpsbgm2 [203.254.230.27]) by mailout2.samsung.com (Oracle Communications Messaging Server 7u4-24.01(7.0.4.24.0) 64bit (built Nov 17 2011)) with ESMTP id <0N9J00JFX02WWXC0@mailout2.samsung.com> for linux-f2fs-devel@lists.sourceforge.net; Wed, 30 Jul 2014 21:59:20 +0900 (KST) In-reply-to: <20140730031820.GC99885@jaegeuk-mac02> Content-language: zh-cn List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linux-f2fs-devel-bounces@lists.sourceforge.net To: 'Jaegeuk Kim' Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net Hi, > -----Original Message----- > From: Jaegeuk Kim [mailto:jaegeuk@kernel.org] > Sent: Wednesday, July 30, 2014 11:18 AM > To: Chao Yu > Cc: linux-kernel@vger.kernel.org; linux-fsdevel@vger.kernel.org; > linux-f2fs-devel@lists.sourceforge.net > Subject: Re: [f2fs-dev] [PATCH 08/11] f2fs: fix wrong condition for unlikely > > On Wed, Jul 30, 2014 at 09:44:43AM +0800, Chao Yu wrote: > > Hi Jaegeuk, > > > > > -----Original Message----- > > > From: Jaegeuk Kim [mailto:jaegeuk@kernel.org] > > > Sent: Saturday, July 26, 2014 6:47 AM > > > To: linux-kernel@vger.kernel.org; linux-fsdevel@vger.kernel.org; > > > linux-f2fs-devel@lists.sourceforge.net > > > Cc: Jaegeuk Kim > > > Subject: [f2fs-dev] [PATCH 08/11] f2fs: fix wrong condition for unlikely > > > > > > This patch fixes the wrongly used unlikely condition. > > > > > > Signed-off-by: Jaegeuk Kim Reviewed-by: Chao Yu > > > --- > > > fs/f2fs/checkpoint.c | 2 +- > > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > > > diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c > > > index 42a16c1..36b0d47 100644 > > > --- a/fs/f2fs/checkpoint.c > > > +++ b/fs/f2fs/checkpoint.c > > > @@ -932,7 +932,7 @@ static void do_checkpoint(struct f2fs_sb_info *sbi, bool is_umount) > > > /* Here, we only have one bio having CP pack */ > > > sync_meta_pages(sbi, META_FLUSH, LONG_MAX); > > > > > > - if (unlikely(!is_set_ckpt_flags(ckpt, CP_ERROR_FLAG))) { > > > + if (!is_set_ckpt_flags(ckpt, CP_ERROR_FLAG)) { > > > > Maybe use likely(!is_set_ckpt_flags(ckpt, CP_ERROR_FLAG)) or > > > > if (unlikely(is_set_ckpt_flags(ckpt, CP_ERROR_FLAG))) > > return; > > > > is more appropriate. How do you think? > > Currently I'd like to put this without any likely or unlikely. > Best thing is to measure some performance how this would make effect on. I think we could get little improvement of performance if we use likely or unlikely here. So if you'd like leave it without pre-judgment, it will be ok. Let's just leave it as it was. :) Thanks, > Until then, it'd be better to do without it, since apparently this should > not be unlikely. > > How about you? > Can we compare both of them explicitly? > > Thanks, > > > > > > clear_prefree_segments(sbi); > > > release_dirty_inode(sbi); > > > F2FS_RESET_SB_DIRT(sbi); > > > -- > > > 1.8.5.2 (Apple Git-48) > > > > > > > > > ------------------------------------------------------------------------------ > > > Want fast and easy access to all the code in your enterprise? Index and > > > search up to 200,000 lines of code with a free copy of Black Duck > > > Code Sight - the same software that powers the world's largest code > > > search on Ohloh, the Black Duck Open Hub! Try it now. > > > http://p.sf.net/sfu/bds > > > _______________________________________________ > > > Linux-f2fs-devel mailing list > > > Linux-f2fs-devel@lists.sourceforge.net > > > https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel ------------------------------------------------------------------------------ Infragistics Professional Build stunning WinForms apps today! Reboot your WinForms applications with our WinForms controls. Build a bridge from your legacy apps to the future. http://pubads.g.doubleclick.net/gampad/clk?id=153845071&iu=/4140/ostg.clktrk