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=-17.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=unavailable 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 092B0C433E0 for ; Mon, 15 Mar 2021 11:29:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D1B7064E20 for ; Mon, 15 Mar 2021 11:29:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230137AbhCOL3U (ORCPT ); Mon, 15 Mar 2021 07:29:20 -0400 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:24134 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229807AbhCOL2x (ORCPT ); Mon, 15 Mar 2021 07:28:53 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1615807733; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=k/i+8wDEvbmjTfeLtLR4DtORse2gYPTQ1pHIrK7qNYU=; b=duNPgY7Sj3HxqYqoVoqh4Ws4ILjtOZkh/QMGs3TTykVK3ycc+MsmljCyFfUNxH/gFcm9NR j4CrH3TvxAfnq3FvODIYh7c0I8jBwxtlk6wHhM46UGH4bWeKPH2lhv3puI1DsDmnUDjQ8O 2vuDRAuiHTC7xg1X6jmPd+51DvNbqAc= Received: from mail-pg1-f200.google.com (mail-pg1-f200.google.com [209.85.215.200]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-416-DHZfKrCnOJqko6-W41IAhA-1; Mon, 15 Mar 2021 07:28:50 -0400 X-MC-Unique: DHZfKrCnOJqko6-W41IAhA-1 Received: by mail-pg1-f200.google.com with SMTP id o9so2658125pgm.15 for ; Mon, 15 Mar 2021 04:28:50 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=k/i+8wDEvbmjTfeLtLR4DtORse2gYPTQ1pHIrK7qNYU=; b=nA/AH56Zpq+8vRbIMqdFUoqm98J/nAYw9jxHubHZPBUbmqASNy+ZHDomeJhP6Q4yrd mfD2duC37U+hes2d56/9rrIckgJdekuHQiJZHq5i6yolS8e7sycfAxOYBoGGdBclR8Uq dCmkDf6MDcVe05ZcJmhQbgsCACS+11wdO2kB4QduALhMhfOZX+yuhHEpl3XaD3GFWhOJ /iW/Yk1SqUOFLa6I2pFADVhWIX3SY08Wmm0UMxb9Iqur7NgOhFLTNqQA79m89tpvI5t/ jbF8yowDrtLnh4Q2IdrlhYLk/CARjW1THZCi1SQXGKgZt4qJVHTt5A6JPHtnF5eR/ovr VKUg== X-Gm-Message-State: AOAM5308FmpLl+jDNerEZqUOG3ZDkLKYWUB6Lg4LNQAvfn2CYDEfa8nk HLZHDzuDXTRrsrjHxikOvlAzM08r98TBKL1wfMNiPi/hglrFQzC9ibD5rsLMt6vIVozrUFU5R7Y k3ddqnEMhIxlJMzj/8t2zxz0W X-Received: by 2002:a17:902:aa87:b029:e5:e1fc:be6 with SMTP id d7-20020a170902aa87b02900e5e1fc0be6mr11730374plr.4.1615807729835; Mon, 15 Mar 2021 04:28:49 -0700 (PDT) X-Google-Smtp-Source: ABdhPJzmWpZTgaL3v2Mj5LM9VDdAu+NKLqarMrzFd4GFRQwFyf4fK7sC/SmQFyQwrbfXAQORInKilg== X-Received: by 2002:a17:902:aa87:b029:e5:e1fc:be6 with SMTP id d7-20020a170902aa87b02900e5e1fc0be6mr11730362plr.4.1615807729632; Mon, 15 Mar 2021 04:28:49 -0700 (PDT) Received: from xiangao.remote.csb ([209.132.188.80]) by smtp.gmail.com with ESMTPSA id t22sm11605800pjw.54.2021.03.15.04.28.47 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 15 Mar 2021 04:28:49 -0700 (PDT) Date: Mon, 15 Mar 2021 19:28:38 +0800 From: Gao Xiang To: Huang Jianan Cc: zhangshiming@oppo.com, guoweichao@oppo.com, linux-erofs@lists.ozlabs.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v5 2/2] erofs: decompress in endio if possible Message-ID: <20210315112838.GB838000@xiangao.remote.csb> References: <20210305062219.557128-1-huangjianan@oppo.com> <20210305095840.31025-1-huangjianan@oppo.com> <20210305095840.31025-2-huangjianan@oppo.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20210305095840.31025-2-huangjianan@oppo.com> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Mar 05, 2021 at 05:58:40PM +0800, Huang Jianan via Linux-erofs wrote: > z_erofs_decompressqueue_endio may not be executed in the atomic > context, for example, when dm-verity is turned on. In this scenario, > data can be decompressed directly to get rid of additional kworker > scheduling overhead. Also, it makes no sense to apply synchronous > decompression for such case. > > Signed-off-by: Huang Jianan > Signed-off-by: Guo Weichao > --- > fs/erofs/internal.h | 2 ++ > fs/erofs/super.c | 1 + > fs/erofs/zdata.c | 16 +++++++++++++--- > 3 files changed, 16 insertions(+), 3 deletions(-) > > diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h > index 67a7ec945686..e325da7be237 100644 > --- a/fs/erofs/internal.h > +++ b/fs/erofs/internal.h > @@ -53,6 +53,8 @@ struct erofs_fs_context { > > /* threshold for decompression synchronously */ > unsigned int max_sync_decompress_pages; > + /* decide whether to decompress synchronously */ > + bool readahead_sync_decompress; I updated this as below: /* current strategy of how to use managed cache */ unsigned char cache_strategy; + /* strategy of sync decompression (false - auto, true - force on) */ + bool readahead_sync_decompress; /* threshold for decompression synchronously */ unsigned int max_sync_decompress_pages; > #endif > unsigned int mount_opt; > }; ... > @@ -720,8 +723,14 @@ static void z_erofs_decompress_kickoff(struct z_erofs_decompressqueue *io, > return; > } > > - if (!atomic_add_return(bios, &io->pending_bios)) > - queue_work(z_erofs_workqueue, &io->u.work); > + if (!atomic_add_return(bios, &io->pending_bios)) { > + if (in_atomic() || irqs_disabled()) { > + queue_work(z_erofs_workqueue, &io->u.work); > + sbi->ctx.readahead_sync_decompress = true; > + } else { > + z_erofs_decompressqueue_work(&io->u.work); > + } > + } Also updated this as below to return as early as possible: - if (!atomic_add_return(bios, &io->pending_bios)) + if (atomic_add_return(bios, &io->pending_bios)) + return; + /* Use workqueue and sync decompression for atomic contexts only */ + if (in_atomic() || irqs_disabled()) { queue_work(z_erofs_workqueue, &io->u.work); + sbi->ctx.readahead_sync_decompress = true; + return; + } + z_erofs_decompressqueue_work(&io->u.work); } Otherwise, it looks good to me. I've applied to dev-test for preliminary testing. Reviewed-by: Gao Xiang Thanks, Gao Xiang