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=-2.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 73C35C43140 for ; Thu, 5 Sep 2019 16:55:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4242020828 for ; Thu, 5 Sep 2019 16:55:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1567702547; bh=0MWJ6ZAls/L7WXz3UVt3svjGiQR65RaWoxBHhcneZIc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=Fp7kvVv5fKPvjmD6UN/LN02rDoZw8w92PMjII5r9hcnafKueHQZXOOGlZ8PJRLmcz JG7yM/c59EefiBuI4MZDBB0c3zHwdrh1p7nHS2wsZB93abGEVaZ2VnHGYOOW2QZpA7 dB0hrSte8qen31GWGnx7nipW5MD4LRcxRXgN0Z1M= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390712AbfIEQzp (ORCPT ); Thu, 5 Sep 2019 12:55:45 -0400 Received: from mail-qt1-f169.google.com ([209.85.160.169]:39423 "EHLO mail-qt1-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731492AbfIEQzp (ORCPT ); Thu, 5 Sep 2019 12:55:45 -0400 Received: by mail-qt1-f169.google.com with SMTP id n7so3615939qtb.6; Thu, 05 Sep 2019 09:55:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=U86ZblmgaF4eBV4iyqRJf/CbV9WbHkWYMeJ0zFkqIu0=; b=TyUOTJJGoo8GODrCt/6YB1x/8aj4n9IE8jT/v+K7tCsOLINcESeyD/Ij4NXtMIB6Sy 17L6qDvWQyCyeC7XEmXxoOnrWrvCkDJaDG0IEmRd9h3bbbHGAAp7YN0Z5zIHZIZQLjXo e7R4fvWV6g6XW9aD+hLJiCg7Lmv5aeBV8tuo+o7VsPjG3fXt7UmiwBwDqQNJlFXWk3TH 5zwtfxF6mzHV0xMeRObFu3TfF099rR2GJ8US0yfbmsALUGRng05iBs5g6jzYHGRvKk8h FRvrTCHS5oUC5grWyibA9V7qghdaMk9oAmt6exGDzNOXAJpBRPdCLJ0cj/yBZJkPaFfd sbuQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:from:to:cc:subject:message-id :references:mime-version:content-disposition:in-reply-to:user-agent; bh=U86ZblmgaF4eBV4iyqRJf/CbV9WbHkWYMeJ0zFkqIu0=; b=AaGh5aAxS1kkttwlWW1hzOrtLI04mgCTsJuuHe/KUgC6l7CNGVlFoGPKxQY3ibD06M SCSC8X+4RRoEDzGI6q36Stpv+YyyKV2Uip9jN10hOteMbSMN4P1pZNZGw7QFRgg59SwG lXnKMoDmohrsgXZpwrR8m/HevTmN134AU2EUOwZnmsQ7A991TtHQV6s57IA0qwAxsZPQ UxuQzbK1g0M4j4KkjffyPFv0n9I4Wx/q3SDwH9sEG/K9kxBtUS9eQhBwEK9SwlspDL12 0qerDkdbz/MXVX3b/Sz5iRqqPsJSsN8d3e24K7YJKCr7n2AsR4efrlUbW4OlPTV0y/z+ PzTA== X-Gm-Message-State: APjAAAU9ptiZiNXOtCObdJWOrdGF8URMTjPe2nFnDjAm8y3UWh5M+8K2 n0vHJVdEe9NZbdwsc7zVwbY= X-Google-Smtp-Source: APXvYqxWVpg+iwFh32fbJZ2IVVdvSiiBQD6AcEmV0uXtGrMn3YPk/UP/cg4q73bDG/04BT3T30UTyg== X-Received: by 2002:ac8:2914:: with SMTP id y20mr4722757qty.150.1567702543675; Thu, 05 Sep 2019 09:55:43 -0700 (PDT) Received: from localhost ([2620:10d:c091:500::1:5196]) by smtp.gmail.com with ESMTPSA id e7sm1083953qto.43.2019.09.05.09.55.42 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 05 Sep 2019 09:55:42 -0700 (PDT) Date: Thu, 5 Sep 2019 09:55:40 -0700 From: Tejun Heo To: Paolo Valente Cc: Jens Axboe , newella@fb.com, clm@fb.com, Josef Bacik , dennisz@fb.com, Li Zefan , Johannes Weiner , linux-kernel , linux-block , kernel-team@fb.com, cgroups@vger.kernel.org, ast@kernel.org, daniel@iogearbox.net, kafai@fb.com, songliubraving@fb.com, yhs@fb.com, bpf@vger.kernel.org Subject: Re: [PATCHSET block/for-next] IO cost model based work-conserving porportional controller Message-ID: <20190905165540.GJ2263813@devbig004.ftw2.facebook.com> References: <20190614015620.1587672-1-tj@kernel.org> <20190614175642.GA657710@devbig004.ftw2.facebook.com> <5A63F937-F7B5-4D09-9DB4-C73D6F571D50@linaro.org> <20190820151903.GH2263813@devbig004.ftw2.facebook.com> <9EB760CE-0028-4766-AE9D-6E90028D8579@linaro.org> <20190831065358.GF2263813@devbig004.ftw2.facebook.com> <88C7DC68-680E-49BB-9699-509B9B0B12A0@linaro.org> <20190902155652.GH2263813@devbig004.ftw2.facebook.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Hello, Paolo. So, I'm currently verifying iocost in the FB fleet. Around three thousand machines running v5.2 (+ some backports) with btrfs on a handful of different models of consumer grade SSDs. I haven't seen complete loss of control as you're reporting. Given that you're reporting the same thing on io.latency, which is deployed on multiple orders of magnitude more machines at this point, it's likely that there's something common affecting your test setup. Can you please describe your test configuration and if you aren't already try testing on btrfs? Thanks. -- tejun