From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 90458C4740A for ; Mon, 9 Sep 2019 11:32:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6419C218AF for ; Mon, 9 Sep 2019 11:32:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404111AbfIILch (ORCPT ); Mon, 9 Sep 2019 07:32:37 -0400 Received: from szxga04-in.huawei.com ([45.249.212.190]:2178 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S2391070AbfIILch (ORCPT ); Mon, 9 Sep 2019 07:32:37 -0400 Received: from DGGEMS407-HUB.china.huawei.com (unknown [172.30.72.59]) by Forcepoint Email with ESMTP id 7A50E883CF089CC4CB43; Mon, 9 Sep 2019 19:32:35 +0800 (CST) Received: from [10.134.22.195] (10.134.22.195) by smtp.huawei.com (10.3.19.207) with Microsoft SMTP Server (TLS) id 14.3.439.0; Mon, 9 Sep 2019 19:32:34 +0800 Subject: Re: [f2fs-dev] [PATCH 1/2] f2fs: do not select same victim right again To: Jaegeuk Kim CC: , References: <20190909012532.20454-1-jaegeuk@kernel.org> <69933b7f-48cc-47f9-ba6f-b5ca8f733cba@huawei.com> <20190909080654.GD21625@jaegeuk-macbookpro.roam.corp.google.com> From: Chao Yu Message-ID: <97237da2-897a-8420-94de-812e94aa751f@huawei.com> Date: Mon, 9 Sep 2019 19:32:07 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <20190909080654.GD21625@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 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2019/9/9 16:06, Jaegeuk Kim wrote: > On 09/09, Chao Yu wrote: >> On 2019/9/9 9:25, Jaegeuk Kim wrote: >>> GC must avoid select the same victim again. >> >> Blocks in previous victim will occupy addition free segment, I doubt after this >> change, FGGC may encounter out-of-free space issue more frequently. > > Hmm, actually this change seems wrong by sec_usage_check(). > We may be able to avoid this only in the suspicious loop? > > --- > fs/f2fs/gc.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c > index e88f98ddf396..5877bd729689 100644 > --- a/fs/f2fs/gc.c > +++ b/fs/f2fs/gc.c > @@ -1326,7 +1326,7 @@ int f2fs_gc(struct f2fs_sb_info *sbi, bool sync, > round++; > } > > - if (gc_type == FG_GC) > + if (gc_type == FG_GC && seg_freed) That's original solution Sahitya provided to avoid infinite loop of GC, but I suggest to find the root cause first, then we added .invalid_segmap for that purpose. Thanks, > sbi->cur_victim_sec = NULL_SEGNO; > > if (sync) >