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 A0CABC4332F for ; Wed, 4 Jan 2023 16:53:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240097AbjADQxx (ORCPT ); Wed, 4 Jan 2023 11:53:53 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44894 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240093AbjADQxh (ORCPT ); Wed, 4 Jan 2023 11:53:37 -0500 Received: from mail-pj1-x102d.google.com (mail-pj1-x102d.google.com [IPv6:2607:f8b0:4864:20::102d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 205C359D3E; Wed, 4 Jan 2023 08:49:30 -0800 (PST) Received: by mail-pj1-x102d.google.com with SMTP id v23so36677957pju.3; Wed, 04 Jan 2023 08:49:30 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:sender:from:to:cc:subject:date:message-id :reply-to; bh=HJHdWmCdPPN2RyEGwBVDj0U8BnKg57ySrkwiPnlykik=; b=VxoCu7wegDYxADC2LeBsfTT8mTk7pkYhPGdcRRyURqqqkbXuC7/9JCVEMB2UycbwKW IFmnhRxSZyF1NZ5lvywX8lVNa5qpsvxfgZ7cGKqY9x2M91/2YDC8dGS1IRFU2aYIlSpz wMYW50334GdGNt80kh9IsnCoHd/76FSNG6kiN5bXY0Xccm7wXz2c7bJHoGfUiGyWH6k+ PxmgQbtGQzW4cLjbnioPRuVTfdBoWqDQVnSF9FtNBIL9TuKGe+QzHhXCp3iyxj66DwHj J666F/CkcmxY+n6IwQRCoBs1cy79fuMetWx/JzS5743lGyYteVZl+YWuVCKM4WeEZnik 4AfQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:sender:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=HJHdWmCdPPN2RyEGwBVDj0U8BnKg57ySrkwiPnlykik=; b=0RlswXo17SPAUrLbEA7DH0qbRehnoJIMm+kkqkZ05WE+zmno04bMeTefUk/0fit3T5 AFHsZrCNRGMihPOr5taQcnwgJ3QGnCzgUEo2Gy4M9Il3Lp2T5H0G8tPuXn85PhFcaC5F uyY+NEUeSQ65o3qM48zKg3QlPSIIDtgEs9m1NwODSWwxp5JwyF9CI0oawJ/iGUIjytlT VSQmd4i9ZqiDp1ympTLiOGwMjyKEPhQJKtGTMwBjrWjCq2CDRr5luqhy/e29HyQ0v/HS KkzWXvM43xWk7UuN/sp/POcSjuheY3yQy4pO8LFctC8kZx4EmEzmrHf+yJgWjWJe8CSR O6XA== X-Gm-Message-State: AFqh2kpRYdizaEYZ3c4aGNQFAigDGwe/TuRE29Gft3E/TKjp2pMFgBOI XtyO8WmAbxVoBvGJkr9MqyakhzdwVOQ= X-Google-Smtp-Source: AMrXdXtSjS6StbSHzd7U0kstj7a0vyrwXOOvTT2LoycKqDp34gcD6yHNFMTapLZIYanePEWsRGalMw== X-Received: by 2002:a05:6a20:66aa:b0:aa:23e1:f8ce with SMTP id o42-20020a056a2066aa00b000aa23e1f8cemr56464427pzh.59.1672850965508; Wed, 04 Jan 2023 08:49:25 -0800 (PST) Received: from localhost (2603-800c-1a02-1bae-a7fa-157f-969a-4cde.res6.spectrum.com. [2603:800c:1a02:1bae:a7fa:157f:969a:4cde]) by smtp.gmail.com with ESMTPSA id j14-20020a170903024e00b001869079d083sm24491497plh.90.2023.01.04.08.49.24 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 04 Jan 2023 08:49:24 -0800 (PST) Sender: Tejun Heo Date: Wed, 4 Jan 2023 06:49:22 -1000 From: Tejun Heo To: Damien Le Moal Cc: linux-ide@vger.kernel.org, linux-block@vger.kernel.org, Jens Axboe , "Maciej S . Szmigiero" , Hannes Reinecke , Christoph Hellwig , Niklas Cassel Subject: Re: [PATCH v7 0/7] Improve libata support for FUA Message-ID: References: <20230103051924.233796-1-damien.lemoal@opensource.wdc.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230103051924.233796-1-damien.lemoal@opensource.wdc.com> Precedence: bulk List-ID: X-Mailing-List: linux-ide@vger.kernel.org Hello, On Tue, Jan 03, 2023 at 02:19:17PM +0900, Damien Le Moal wrote: > Finally, patch 7 enables FUA support by default in libata for devices > supporting this features. These optional features tend to be broken in various and subtle ways, especially the ones which don't show clear and notable advantages and thus don't get used by everybody. I'm not necessarily against enabling it by default but we should have better justifications as we might unnecessarily cause a bunch of painful and subtle failures which can take a while to sort out. * Can the advantages of using FUA be demonstrated in a realistic way? IOW, are there workloads which clearly benefit from FUA? My memory is hazy but we only really use FUA from flush sequence to turn flush, write, flush sequence into flush, FUA-write. As all the heavy lifting is done in the first flush anyway, I couldn't find a case where that optimization made a meaningful difference but I didn't look very hard. * Do we know how widely FUA is used now? IOW, is windows using FUA by default now? If so, do we know whether they have a blocklist? Thanks. -- tejun