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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7ECC8C77B70 for ; Mon, 17 Apr 2023 06:54:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230245AbjDQGyV (ORCPT ); Mon, 17 Apr 2023 02:54:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48046 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230117AbjDQGyT (ORCPT ); Mon, 17 Apr 2023 02:54:19 -0400 Received: from out30-113.freemail.mail.aliyun.com (out30-113.freemail.mail.aliyun.com [115.124.30.113]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3C753DF for ; Sun, 16 Apr 2023 23:53:36 -0700 (PDT) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R201e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018046059;MF=hsiangkao@linux.alibaba.com;NM=1;PH=DS;RN=8;SR=0;TI=SMTPD_---0VgELZVh_1681714379; Received: from 30.97.49.3(mailfrom:hsiangkao@linux.alibaba.com fp:SMTPD_---0VgELZVh_1681714379) by smtp.aliyun-inc.com; Mon, 17 Apr 2023 14:53:00 +0800 Message-ID: <26cdf7b0-5d7d-68ba-da76-1ad800708946@linux.alibaba.com> Date: Mon, 17 Apr 2023 14:52:59 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:102.0) Gecko/20100101 Thunderbird/102.9.1 Subject: Re: [PATCH] erofs: remove unneeded icur field from struct z_erofs_decompress_frontend To: Yue Hu , xiang@kernel.org, chao@kernel.org, linux-erofs@lists.ozlabs.org Cc: jefflexu@linux.alibaba.com, linux-kernel@vger.kernel.org, huyue2@coolpad.com, zhangwen@coolpad.com References: <20230417064136.5890-1-zbestahu@gmail.com> From: Gao Xiang In-Reply-To: <20230417064136.5890-1-zbestahu@gmail.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2023/4/17 14:41, Yue Hu wrote: > From: Yue Hu > > The icur field is only used in z_erofs_try_inplace_io(). Let's just use > a local variable instead. And no need to check if the pcluster is inline > when setting icur since inline page cannot be used for inplace I/O. > > Signed-off-by: Yue Hu Nope, it's a behavior change. Other users could feed more inplace I/O pages before I/O submission to reduce memory consumption, it's common when applying stress model in low memory scenarios. Thanks, Gao Xiang > --- > fs/erofs/zdata.c | 13 +++++-------- > 1 file changed, 5 insertions(+), 8 deletions(-) > > diff --git a/fs/erofs/zdata.c b/fs/erofs/zdata.c > index f759152feffa..f8bf2b227942 100644 > --- a/fs/erofs/zdata.c > +++ b/fs/erofs/zdata.c > @@ -554,9 +554,6 @@ struct z_erofs_decompress_frontend { > /* used for applying cache strategy on the fly */ > bool backmost; > erofs_off_t headoffset; > - > - /* a pointer used to pick up inplace I/O pages */ > - unsigned int icur; > }; > > #define DECOMPRESS_FRONTEND_INIT(__i) { \ > @@ -707,11 +704,13 @@ static bool z_erofs_try_inplace_io(struct z_erofs_decompress_frontend *fe, > struct z_erofs_bvec *bvec) > { > struct z_erofs_pcluster *const pcl = fe->pcl; > + /* file-backed online pages are traversed in reverse order */ > + unsigned int icur = pcl->pclusterpages; > > - while (fe->icur > 0) { > - if (!cmpxchg(&pcl->compressed_bvecs[--fe->icur].page, > + while (icur > 0) { > + if (!cmpxchg(&pcl->compressed_bvecs[--icur].page, > NULL, bvec->page)) { > - pcl->compressed_bvecs[fe->icur] = *bvec; > + pcl->compressed_bvecs[icur] = *bvec; > return true; > } > } > @@ -877,8 +876,6 @@ static int z_erofs_collector_begin(struct z_erofs_decompress_frontend *fe) > } > z_erofs_bvec_iter_begin(&fe->biter, &fe->pcl->bvset, > Z_EROFS_INLINE_BVECS, fe->pcl->vcnt); > - /* since file-backed online pages are traversed in reverse order */ > - fe->icur = z_erofs_pclusterpages(fe->pcl); > return 0; > } >