From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752727AbdKIRve (ORCPT ); Thu, 9 Nov 2017 12:51:34 -0500 Received: from mail.kernel.org ([198.145.29.99]:49428 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750984AbdKIRvc (ORCPT ); Thu, 9 Nov 2017 12:51:32 -0500 DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1FA60218EB Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=jaegeuk@kernel.org Date: Thu, 9 Nov 2017 09:51:29 -0800 From: Jaegeuk Kim To: Chao Yu Cc: linux-f2fs-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org, chao@kernel.org, mhocko@kernel.org Subject: Re: [PATCH v2 1/3] f2fs: avoid opened loop codes in __add_ino_entry Message-ID: <20171109175129.GA55844@jaegeuk-macbookpro.roam.corp.google.com> References: <20171107054142.6242-1-yuchao0@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20171107054142.6242-1-yuchao0@huawei.com> User-Agent: Mutt/1.8.2 (2017-04-18) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Chao, On 11/07, Chao Yu wrote: > We will keep __add_ino_entry success all the time, for ENOMEM failure > case, we have already handled it by using __GFP_NOFAIL flag, so we > don't have to use additional opened loop codes here, remove them. > > Signed-off-by: Chao Yu > --- > v2: > As Michal Hocko suggested, with __GFP_NOFAIL, MM will do all it can for > memory allocation including access memory reserves, so it's better to > use it rather than opened loop code, update this patch for it. > fs/f2fs/checkpoint.c | 19 +++++++++++-------- > 1 file changed, 11 insertions(+), 8 deletions(-) > > diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c > index 98777c1ae70c..80b90146cff2 100644 > --- a/fs/f2fs/checkpoint.c > +++ b/fs/f2fs/checkpoint.c > @@ -405,20 +405,21 @@ static void __add_ino_entry(struct f2fs_sb_info *sbi, nid_t ino, > { > struct inode_management *im = &sbi->im[type]; > struct ino_entry *e, *tmp; > + bool preloaded; > + int err; > > tmp = f2fs_kmem_cache_alloc(ino_entry_slab, GFP_NOFS); > -retry: > - radix_tree_preload(GFP_NOFS | __GFP_NOFAIL); > + > + preloaded = !radix_tree_preload(GFP_NOFS | __GFP_NOFAIL); > + f2fs_bug_on(sbi, !preloaded); I don't think we need this by adding new useless variable. > > spin_lock(&im->ino_lock); > e = radix_tree_lookup(&im->ino_root, ino); > if (!e) { > e = tmp; > - if (radix_tree_insert(&im->ino_root, ino, e)) { How about just adding this? if (unlikely(radix_tree_insert(&im->ino_root, ino, e))) f2fs_bug_on(sbi, 1); > - spin_unlock(&im->ino_lock); > - radix_tree_preload_end(); > - goto retry; > - } > + err = radix_tree_insert(&im->ino_root, ino, e); > + f2fs_bug_on(sbi, err); > + > memset(e, 0, sizeof(struct ino_entry)); > e->ino = ino; > > @@ -431,7 +432,9 @@ static void __add_ino_entry(struct f2fs_sb_info *sbi, nid_t ino, > f2fs_set_bit(devidx, (char *)&e->dirty_device); > > spin_unlock(&im->ino_lock); > - radix_tree_preload_end(); > + > + if (preloaded) > + radix_tree_preload_end(); > > if (e != tmp) > kmem_cache_free(ino_entry_slab, tmp); > -- > 2.15.0.55.gc2ece9dc4de6