From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755475AbdKJBHy (ORCPT ); Thu, 9 Nov 2017 20:07:54 -0500 Received: from szxga04-in.huawei.com ([45.249.212.190]:10429 "EHLO szxga04-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755255AbdKJBHx (ORCPT ); Thu, 9 Nov 2017 20:07:53 -0500 Subject: Re: [PATCH v2 1/3] f2fs: avoid opened loop codes in __add_ino_entry To: Jaegeuk Kim CC: , , , References: <20171107054142.6242-1-yuchao0@huawei.com> <20171109175129.GA55844@jaegeuk-macbookpro.roam.corp.google.com> From: Chao Yu Message-ID: <3ef4ee57-f88c-633b-dcdc-b2664df81bfa@huawei.com> Date: Fri, 10 Nov 2017 09:07:11 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.3.0 MIME-Version: 1.0 In-Reply-To: <20171109175129.GA55844@jaegeuk-macbookpro.roam.corp.google.com> Content-Type: text/plain; charset="windows-1252" Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.134.22.195] X-CFilter-Loop: Reflected X-Mirapoint-Virus-RAPID-Raw: score=unknown(0), refid=str=0001.0A020202.5A04FBD7.0104,ss=1,re=0.000,recu=0.000,reip=0.000,cl=1,cld=1,fgs=0, ip=0.0.0.0, so=2014-11-16 11:51:01, dmn=2013-03-21 17:37:32 X-Mirapoint-Loop-Id: e53e82ecde895cb2b141abdde1d8658b Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2017/11/10 1:51, Jaegeuk Kim wrote: > 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. Yup, let me update it. > >> >> 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); Okay. Thanks, > >> - 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 > > . >