From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.10]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 048E019992C; Fri, 30 Aug 2024 12:01:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.10 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725019318; cv=none; b=M41vA3rfMdjJKhfyHK1ofPo1x0ovePYw7/K1qCqxmn3B4tIdH1XPkwQEsMhSj60BdicBD/ngktoGVDONUqIRbc1RAvwQCLLCqBpM2newW6mmjyb6yNM1+cyPtqYIVsDzOR5CKNAnb0iD2+gWwTxiXT47d4CYeP1v+CPJ3WzH9gU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725019318; c=relaxed/simple; bh=E72GKG427WbHUAlEX1PF2kGDsmhjOHh7crmqXQZrAQI=; h=Message-ID:Subject:From:To:Cc:Date:In-Reply-To:References: Content-Type:MIME-Version; b=FxP/8PFBZcOWnvs/7b7bWlqHssLSwsQlZCpql9pt8Wn6Jbf3c0+VlORffBlc4LqEffjuEBPrPmyGsjqU7YTE242usEKcYF0Mw7MIx3v67BXjY8+F8LM2yWApWnIRnXXyn4xi4JctP1TkPsocg5dZLGb3s/wQ11HqiI+3uE+XoUo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=none smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=kRnkBZ9k; arc=none smtp.client-ip=198.175.65.10 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="kRnkBZ9k" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1725019317; x=1756555317; h=message-id:subject:from:to:cc:date:in-reply-to: references:content-transfer-encoding:mime-version; bh=E72GKG427WbHUAlEX1PF2kGDsmhjOHh7crmqXQZrAQI=; b=kRnkBZ9kjjZk0VMWn94ce9Q7NWOkBsHjc+LsHaG9Z4daqp57WfMKql1V VUIM4XRI/FtCXVMTX7llfoD5CfTIFyLhunBw7nDQor89HarU/Eu6ha5Wx HTaPyFcu5/LlkWv+Vdr8O20QdvxAavBwuuWMIXkAkJx+y98eatTFaqcDl rSwDWwUN5Gv4nhvZ30NvZD+N00SMUqFzEV2eyZ4K4ozpfOPVzhh5O9H5W pEtYKWDJITXVBi5+5RfsePdAc7667SPkAglcbGyrlz2tLfunziOYNuvHy 4dmy5PQx/pUsWB5ceEMr/ojfpf3BhRpI/Qx2Fb80UkFp/kw+U9d8lCqtj w==; X-CSE-ConnectionGUID: pEdOqsuuSmispRvt9gS4OA== X-CSE-MsgGUID: mFa7Rd6fSfS1FLPCmZbyCA== X-IronPort-AV: E=McAfee;i="6700,10204,11179"; a="41138222" X-IronPort-AV: E=Sophos;i="6.10,188,1719903600"; d="scan'208";a="41138222" Received: from orviesa008.jf.intel.com ([10.64.159.148]) by orvoesa102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 30 Aug 2024 05:01:56 -0700 X-CSE-ConnectionGUID: xKVIgp6SQFqtUiQBWwsmAg== X-CSE-MsgGUID: mrR2uUrYTS2iA9T6gertpQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.10,188,1719903600"; d="scan'208";a="64628677" Received: from mwiniars-desk2.ger.corp.intel.com ([10.245.246.70]) by orviesa008-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 30 Aug 2024 05:01:55 -0700 Message-ID: Subject: Re: [RFC PATCH 0/2] block: CPU latency PM QoS tuning From: Tero Kristo To: Bart Van Assche , axboe@kernel.dk Cc: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org Date: Fri, 30 Aug 2024 15:01:51 +0300 In-Reply-To: <517e19eb-010c-4509-bec3-c3f8316f2c0f@acm.org> References: <20240829075423.1345042-1-tero.kristo@linux.intel.com> <517e19eb-010c-4509-bec3-c3f8316f2c0f@acm.org> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.52.3-0ubuntu1 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 On Thu, 2024-08-29 at 07:04 -0400, Bart Van Assche wrote: > On 8/29/24 3:18 AM, Tero Kristo wrote: > > Any thoughts about the patches and the approach taken? >=20 > The optimal value for the PM QoS latency depends on the request size > and on the storage device characteristics. I think it would be better > if the latency value would be chosen automatically rather than > introducing yet another set of tunable sysfs parameters. Are these device parameters stored somewhere in the kernel? I did try looking for this kind of data but could not find anything useful; thats the main reason I implemented the sysfs tunables. -Tero >=20 > Thanks, >=20 > Bart. >=20