Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753224AbdIDCtC (ORCPT ); Sun, 3 Sep 2017 22:49:02 -0400 Received: from szxga04-in.huawei.com ([45.249.212.190]:5512 "EHLO szxga04-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753124AbdIDCtA (ORCPT ); Sun, 3 Sep 2017 22:49:00 -0400 Subject: Re: [PATCH] f2fs: clear get_ssr_cost To: Yunlong Song , , , CC: , , , , References: <1504268075-81858-1-git-send-email-yunlong.song@huawei.com> <2503831f-3868-4037-307d-1e5fb4833a29@huawei.com> From: Chao Yu Message-ID: Date: Mon, 4 Sep 2017 10:48:43 +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: 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=0001.0A0B0205.59ACBF10.0068,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: b4088d526ea95be72007d4d00d570429 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1860 Lines: 62 On 2017/9/4 9:54, Yunlong Song wrote: > The update_sit_entry provides this: > ... > 1658 if (!f2fs_test_bit(offset, se->ckpt_valid_map)) > 1659 se->ckpt_valid_blocks += del; > ... > As a result, the ckpt_valid_blocks is always larger than valid_blocks. > If not correct, can you provide > the case valid_blocks larger than ckpt_valid_blocks? Oh, I just nit-pick, :), how about using 'se->ckpt_valid_blocks will never be smaller than se->valid_blocks' instead? And could you just revert Yunlei's patch and add above commit log? Thanks, > > On 2017/9/4 9:17, Chao Yu wrote: >> On 2017/9/1 20:14, Yunlong Song wrote: >>> se->ckpt_valid_blocks is always larger than se->valid_blocks, so >>> get_ssr_cost can be cleared. >> I think this is not correct. >> >> Thanks, >> >>> Signed-off-by: Yunlong Song >>> --- >>> fs/f2fs/gc.c | 11 +---------- >>> 1 file changed, 1 insertion(+), 10 deletions(-) >>> >>> diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c >>> index cd147e7..b226760 100644 >>> --- a/fs/f2fs/gc.c >>> +++ b/fs/f2fs/gc.c >>> @@ -277,20 +277,11 @@ static unsigned int get_greedy_cost(struct f2fs_sb_info *sbi, >>> valid_blocks * 2 : valid_blocks; >>> } >>> >>> -static unsigned int get_ssr_cost(struct f2fs_sb_info *sbi, >>> - unsigned int segno) >>> -{ >>> - struct seg_entry *se = get_seg_entry(sbi, segno); >>> - >>> - return se->ckpt_valid_blocks > se->valid_blocks ? >>> - se->ckpt_valid_blocks : se->valid_blocks; >>> -} >>> - >>> static inline unsigned int get_gc_cost(struct f2fs_sb_info *sbi, >>> unsigned int segno, struct victim_sel_policy *p) >>> { >>> if (p->alloc_mode == SSR) >>> - return get_ssr_cost(sbi, segno); >>> + return get_seg_entry(sbi, segno)->ckpt_valid_blocks; >>> >>> /* alloc_mode == LFS */ >>> if (p->gc_mode == GC_GREEDY) >>> >> >> . >> >