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=-6.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED 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 DBF64C433F4 for ; Wed, 19 Sep 2018 15:40:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 833F32150B for ; Wed, 19 Sep 2018 15:40:24 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=aol.com header.i=@aol.com header.b="nyNpIlPR" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 833F32150B Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=aol.com 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 S1732527AbeISVSv (ORCPT ); Wed, 19 Sep 2018 17:18:51 -0400 Received: from sonic302-21.consmr.mail.gq1.yahoo.com ([98.137.68.147]:40177 "EHLO sonic302-21.consmr.mail.gq1.yahoo.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732164AbeISVSv (ORCPT ); Wed, 19 Sep 2018 17:18:51 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=aol.com; s=a2048; t=1537371621; bh=KXiHp3D9aUD5+TAcD63qLbF10gk3auQa1PodmqpCqUs=; h=Subject:To:Cc:References:From:Date:In-Reply-To:From:Subject; b=nyNpIlPRotz5fpaft+HLakPac2sm2xq6i6z9nkFvh4DNG65rEMkq4l6MVFZs3pUpggrxifI7YiWpIzau2Ap132ZxQxp7F7qYqTLqb6FXCpSnlN+F4Uxlwaiiay7YlCUob+bCH1kXO15kxxFnK93S39XwqVcCNGQZQbh262gMKC9yZtiZidQFPMP9aA2WwMZQ446Q1SsNbSFxVjx87PV8QtdGHGMzqTAvwlH/fjGyqH+eGm1DGnEQVC/U2b0Nf+KVaDF3CsamCYfAf8QJi7v+iWV64lAPJtN+sRGNJo2J/svb0FG9o+7QfuMgHvAPb8cKBTA1TTbGE0D/nXvFlKtHNg== X-YMail-OSG: 7gJoFw4VM1mY8W2dEomn0uRHXPlOiu02_8y1AIKDzBizI504LsVSDthKUiuTkIO AywXfwSwGde4ijvDEIU2uEHEodorplwOq5GH4_f4..JNoWcnk_OD4.KGELEKh_y5cQ9At5gNgOEC pOufh9DUYXaiJ5T5ecTFDx9sG1upTYOj9vfQ9x.eNYmNdUPzHAP352uGccyIwQ.P654cnQSVVlgj OyHEHbFbjsmspsmk1fczQsZzf0gKLDQs1cqhc5cTqFwTXwhsO1KhmqEojPbGn5UXNx6Gd1bzPgAS z266oJXnF4b6O5subQYvzJvwqDH84V2k5H9RWVwQqWp6I79ikPimFxJKbPIYsEXgRAACOBDnDirw UvcbxHJPzuntJltr.YWFgORTkRJNL7es2ZDrKCAnyGAEKQ1D8.l8mcWm110o6Wo9C5uLW2edHYqc pq6NL.FM5OnB49ohe4SqL_c_DwUBUq0rmIrm9pfCdYT1yxP1K8xeyFcPpCCYpR9n49MB5lmCiB1i SoGSxbiRC93Ip7ONLfxVlxzzhSenEioOfg4qeJbl6UpxRwFtSunpdxJKHYhNV0v806pNBuH8vnvH KytKzclSjvBejvk.sq6jUvF2yp2x8MNz72lGOO6.hOyEcy62DAAk3ZpILqvXZKKJP5I5In.Tcxtd SZtbBcgh7e.HIhalOxgBAyAwn2LmNFQdxpe18pQaX8Z_Y7aGxDJWoLdDd9mX_V59YMo5GKbjQ84A UicGTVik7DIOcSwjKOm7AHLNdWRfY1zsyEsOnAO_nDGl_HkMeM8gH4.NHayawgL5FxV80D3z0kHV le3xZu5lY8ariHxfrcQFngS3uMlv05WGv5ylgUAOKSF0YFh5E1NWO1ooK.IdmuuvjUylNHdoSm7g TVeWi1rARHn3r0iLsPjqj8NOEXFomJrPXh9qioyXbgnRaKOkHa7eZaKkdA16TcWZgKhGJTFPPAE5 qW6gH7ct_EI9IiUA7ZgA7AttuMyF0TM9wgDpoSmBKjFs.kaMhhLXd2aLjY98swuq_P6Zqu_Z7UDb xZfU- Received: from sonic.gate.mail.ne1.yahoo.com by sonic302.consmr.mail.gq1.yahoo.com with HTTP; Wed, 19 Sep 2018 15:40:21 +0000 Received: from 180.173.110.117 (EHLO [192.168.1.3]) ([180.173.110.117]) by smtp413.mail.gq1.yahoo.com (Oath Hermes SMTP Server) with ESMTPA ID 28bd4440c9616d1e959253b8a45d5185; Wed, 19 Sep 2018 15:40:20 +0000 (UTC) Subject: Re: [PATCH 4/6] staging: erofs: cleanup `z_erofs_vle_normalaccess_readpages' To: Chao Yu , Chao Yu Cc: devel@driverdev.osuosl.org, Greg Kroah-Hartman , Miao Xie , LKML , Du Wei , linux-erofs@lists.ozlabs.org References: <1537336150-90604-1-git-send-email-gaoxiang25@huawei.com> <1537336150-90604-4-git-send-email-gaoxiang25@huawei.com> <1b38cbfe-70e0-1e6d-fa50-89b1fddeeb43@kernel.org> From: Gao Xiang Message-ID: <84d5403d-2849-0ba9-d027-9a1c770c271c@aol.com> Date: Wed, 19 Sep 2018 23:40:15 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Chao, On 2018/9/19 23:32, Gao Xiang via Linux-erofs wrote: > Hi Chao, > > On 2018/9/19 23:26, Chao Yu wrote: >> Hi Xiang, >> >> On 2018/9/19 13:49, Gao Xiang wrote: >>> This patch introduces `__should_decompress_synchronously' to >>> cleanup `z_erofs_vle_normalaccess_readpages'. >>> >>> Signed-off-by: Gao Xiang >>> --- >>> drivers/staging/erofs/internal.h | 11 +++++++++++ >>> drivers/staging/erofs/super.c | 5 +++++ >>> drivers/staging/erofs/unzip_vle.c | 20 ++++++-------------- >>> 3 files changed, 22 insertions(+), 14 deletions(-) >>> >>> diff --git a/drivers/staging/erofs/internal.h b/drivers/staging/erofs/internal.h >>> index cfcc6db..c84eb97 100644 >>> --- a/drivers/staging/erofs/internal.h >>> +++ b/drivers/staging/erofs/internal.h >>> @@ -95,6 +95,9 @@ struct erofs_sb_info { >>> /* the dedicated workstation for compression */ >>> struct radix_tree_root workstn_tree; >>> >>> + /* threshold for decompression synchronously */ >>> + unsigned int max_sync_decompress_pages; >>> + >>> #ifdef EROFS_FS_HAS_MANAGED_CACHE >>> struct inode *managed_cache; >>> #endif >>> @@ -273,6 +276,14 @@ extern int erofs_try_to_free_cached_page(struct address_space *mapping, >>> struct page *page); >>> #endif >>> >>> +#define DEFAULT_MAX_SYNC_DECOMPRESS_PAGES 4 >>> + >>> +static inline bool __should_decompress_synchronously(struct erofs_sb_info *sbi, >>> + unsigned int nr) >>> +{ >>> + return nr <= sbi->max_sync_decompress_pages; >> - nr_pages < 4 /* sync */); >> >> There is a little bit changed except cleanup, IIUC, would it be any difference >> of performance around boundary of four pages? > > No.. Once synchronous decompression is applied for 1,2,3 pages for no special reasons. > But I think it could be better to adjust it to the power of two --- 1,2,3,4 is preferred. > Since I have no idea to measure which is better or what value is best for all platform or use cases... > > Therefore I tune it in this patch since I don't like the number > DEFAULT_MAX_SYNC_DECOMPRESS_PAGES == 3 ... p.s. If you think that is not the cleanup meaning, I will resend this patch with the original 3. Both are ok for me. it is a minor tuning and I don't have a way to measure which is better and the best boundary. Thanks, Gao Xiang > > Thanks, > Gao Xiang > >> >> Thanks, >>