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=-2.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_PASS,T_DKIMWL_WL_HIGH,USER_AGENT_MUTT 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 06EE0C46460 for ; Fri, 10 Aug 2018 01:46:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A0D44223B8 for ; Fri, 10 Aug 2018 01:46:17 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="Rz0Irsot" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A0D44223B8 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727102AbeHJENu (ORCPT ); Fri, 10 Aug 2018 00:13:50 -0400 Received: from mail.kernel.org ([198.145.29.99]:57560 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725724AbeHJENu (ORCPT ); Fri, 10 Aug 2018 00:13:50 -0400 Received: from localhost (unknown [104.132.1.88]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 15346223B7; Fri, 10 Aug 2018 01:46:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1533865575; bh=kU7wd235Scz+aeV7FoBSwpuBjvwQgvRLEp3RECV+Bek=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Rz0IrsotO9QOSnKj9AHeDN1u7KVbpdTO0s/3Oz36/MJvgdCgdvj4NuBWA8T+MGJAO dvgZIrDmjRQOhgb232QGDu75lpkdRmRuOXXt0CYJscOvF3UPYlW1EHsQM4SkmaebyS 7CfxguKgqY6GRxL2CWHUsQYN4BUBJsOk7a/F/szU= Date: Thu, 9 Aug 2018 18:46:14 -0700 From: Jaegeuk Kim To: Chao Yu Cc: linux-kernel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net Subject: Re: [f2fs-dev] [PATCH v3] f2fs: avoid fi->i_gc_rwsem[WRITE] lock in f2fs_gc Message-ID: <20180810014614.GA44979@jaegeuk-macbookpro.roam.corp.google.com> References: <20180730013242.15647-1-jaegeuk@kernel.org> <20180804222954.GB35077@jaegeuk-macbookpro.roam.corp.google.com> <20180805163450.GB55836@jaegeuk-macbookpro.roam.corp.google.com> <16d7f719-268f-99f4-c5b2-fc893b557f11@huawei.com> <20180809195917.GA27087@jaegeuk-macbookpro.roam.corp.google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.8.2 (2017-04-18) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 08/10, Chao Yu wrote: > On 2018/8/10 3:59, Jaegeuk Kim wrote: > > Yup, how about this? > > > > diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c > > index d816c328f02b..cb510fb36523 100644 > > --- a/fs/f2fs/gc.c > > +++ b/fs/f2fs/gc.c > > @@ -1052,6 +1052,7 @@ int f2fs_gc(struct f2fs_sb_info *sbi, bool sync, > > .iroot = RADIX_TREE_INIT(gc_list.iroot, GFP_NOFS), > > }; > > unsigned long long last_skipped = sbi->skipped_atomic_files[FG_GC]; > > + unsigned long long first_skipped; > > unsigned int skipped_round = 0, round = 0; > > > > trace_f2fs_gc_begin(sbi->sb, sync, background, > > @@ -1064,8 +1065,10 @@ int f2fs_gc(struct f2fs_sb_info *sbi, bool sync, > > prefree_segments(sbi)); > > > > cpc.reason = __get_cp_reason(sbi); > > - sbi->skipped_gc_rwsem = 0; > > gc_more: > > + sbi->skipped_gc_rwsem = 0; > > + first_skipped = last_skipped; > > + > > if (unlikely(!(sbi->sb->s_flags & SB_ACTIVE))) { > > ret = -EINVAL; > > goto stop; > > @@ -1126,8 +1129,8 @@ int f2fs_gc(struct f2fs_sb_info *sbi, bool sync, > > goto gc_more; > > } > > > > - if (sbi->skipped_atomic_files[FG_GC] == last_skipped && > > - sbi->skipped_atomic_files[FG_GC] > > > + if (first_skipped < last_skipped && > > + (last_skipped - first_skipped) > > > IMO, it would be better to judge the condition with skipped number in all round > of FGGC instead of last round, since number in last round may not very accurate. Yup, moved before gc_more. > > Thoughts? > > Thanks, > > > sbi->skipped_gc_rwsem) { > > f2fs_drop_inmem_pages_all(sbi, true); > > segno = NULL_SEGNO; > > > > . > >