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=-3.6 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 16CA1C2D0E4 for ; Fri, 13 Nov 2020 02:08:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A3D2720936 for ; Fri, 13 Nov 2020 02:08:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="vR69DQhL" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726150AbgKMCI4 (ORCPT ); Thu, 12 Nov 2020 21:08:56 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55134 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726017AbgKMCIz (ORCPT ); Thu, 12 Nov 2020 21:08:55 -0500 Received: from mail-pl1-x62e.google.com (mail-pl1-x62e.google.com [IPv6:2607:f8b0:4864:20::62e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E236EC0613D1 for ; Thu, 12 Nov 2020 18:08:55 -0800 (PST) Received: by mail-pl1-x62e.google.com with SMTP id b3so3773886pls.11 for ; Thu, 12 Nov 2020 18:08:55 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=U+tyHoASzP5x/Mksbk7prp57nkt63lLOrO8FFA2ktxM=; b=vR69DQhLMxlZ5vNqkrQlfxFmJio385ptguN1fKu8ZVm1dhi6dCzaOsepVHGyu2E4qQ tX8jW9xqvnw/LCzrLALP2929A/TpxsEK0UmceGJJEjzBzeOgizxnGIRh1OlyTnBYuepS lbBXLvw+lTI7NDLziw7mwLYVpyjkxzjP70pgC8dqxpWdlaYnzzYF3w6pJkx4zVsHXoXJ 7Q62Kd7TVsRS8H+JCehsnaAr1mqVfjd01X8SdhNmrwJGt0NXU2sSq2qUxiS8dOBBZ4E3 TpYRSVxsB8FM2CbijdIkvbYa3yHcDIwE+1XRQN5UAH+GiN4IpODr34N6njQAEzC8s6F8 pVKg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc:content-transfer-encoding; bh=U+tyHoASzP5x/Mksbk7prp57nkt63lLOrO8FFA2ktxM=; b=CFa8eqRg/ld035krbFjFDlQw7PvxnCZXWrTa5nJZN2k60nRJdJwt9hOV/G9kCMbsq5 nNypJFfL2oRvp9FvjBlGEA7UcPWAB7ke/XzHBOg2zzyXwQhBgocmaIrd0n7kKiYF3oB6 MmK5aaD2DyJpxScqQayUMHBuCcV7FCVNRip8OFauC4GANTQEpmEJ1ReanpasVY49lFDj zaRy6X7vTpB7ytRYrOFZsmkfE/Ax5UF//Gyd0kbDTk5ik2xAwgcEvleNJWaKPh4vmRK+ 8vuHBGvDEFDoUGJ7+HThRbtvL/tYEckDQLt8hxYMet+sx5TeRrMj4hCHyTF7CzXWxLyS qQcw== X-Gm-Message-State: AOAM531MNIFtMX+bhmPf5/8ovpw/S7Euan2JQ7pvAUUP+QBM80fXBbyW XZJehBfZWCFAQ9LM9VRxhihevZ1oWp8EaBwVdVmuluaV6zFe5A== X-Google-Smtp-Source: ABdhPJylSrMSzKWwT4OFbrIiUtlK9q30aLwavKGwEVpLkCnMmHiPQkgc/qGO0Ja5vZk06cHSQb9/PW68UWEKGxvHM2E= X-Received: by 2002:a17:902:8e84:b029:d7:eb0d:2fe6 with SMTP id bg4-20020a1709028e84b02900d7eb0d2fe6mr2420187plb.16.1605233335472; Thu, 12 Nov 2020 18:08:55 -0800 (PST) MIME-Version: 1.0 References: In-Reply-To: From: Sage Meng Date: Fri, 13 Nov 2020 10:08:42 +0800 Message-ID: Subject: Re: Is there a way to make Cephfs kernel client to send data to Ceph cluster smoothly with buffer io To: Jeff Layton Cc: ceph-devel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: ceph-devel@vger.kernel.org It would be nice if there was a mount option to have such parameters adjusted that only influence CephFS Kernel Client. Jeff Layton =E4=BA=8E2020=E5=B9=B411=E6=9C=8812=E6=97= =A5=E5=91=A8=E5=9B=9B =E4=B8=8B=E5=8D=8811:59=E5=86=99=E9=81=93=EF=BC=9A > > On Thu, 2020-11-12 at 23:17 +0800, Sage Meng wrote: > > Hi All, > > > > Cephfs kernel client is influenced by kernel page cache when we > > write data to it, outgoing data will be huge when os starts to flush > > page cache. So Is there a way to make Cephfs kernel client to send > > data to ceph cluster smoothly when buffer io is used ? Better a way > > that only influence Ceph IO not the whole system IO. > > Not really. > > The ceph client just does what the VM subsys asks it to do. If the VM > says "write out these pages", then it'll do it -- otherwise they'll just > sit there dirty. > > Usually you need to tune things like the dirty_ratio and > dirty_background_ratio to smooth this sort of thing out, but those are > system-wide knobs. > > Another alternative is to strategically fsync or syncfs from time to > time, but that's sort of outside the scope of the kernel client. > -- > Jeff Layton >