From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id F3B6155821D; Tue, 8 Sep 2026 15:44:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788882299; cv=none; b=H6EpX9qk6w2dFH2/1V0WAxXGE1AxILbacXQYTXmX1ge+G9E6LqOI8BJB2BdSMjZf9m1fJNGQeoLNa4EiATXfCBI6x12/Pr4J0qLl+Dqln3AwioHwY3w1s9oRMMi2Zz63OhF1TosayDKn9pRwodJXSI750P5UVXtHTQj3M7VGxgM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788882299; c=relaxed/simple; bh=GxMGnXYQeONzqdK6e7ly+Ryxj5+TnaiGzWadzF9ASqg=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=GruLx8RQ6AI7L/IhKuDwFCz6m+oDHWzapY85vorL8E3zorXWdnDFs61QKcHNEwowYdH68FTqKxgIFtT6x7aeCQP7ht5zIEffOskufZdhrr4kWgKGzy5alWR32f6AH2Sz1DmBxynF4XcwNr+nk+US06u0UXdUwdpBMgiW/tcRbhU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b=LcW3d8Y9; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b="LcW3d8Y9" Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 8FB551477; Tue, 8 Sep 2026 08:44:52 -0700 (PDT) Received: from [10.2.212.8] (e134344.arm.com [10.2.212.8]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 4C3123F7B4; Tue, 8 Sep 2026 08:44:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1788882296; bh=GxMGnXYQeONzqdK6e7ly+Ryxj5+TnaiGzWadzF9ASqg=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=LcW3d8Y9EnhgIb3Rlfc88EUwA1NZjt8vavC27AHR9l+iN18v85ITcyWSQsN/UPN4o OLvqyDegHcjXhNJgmbuN3xh1uOIo2IZyl07gOyc3Vx/FuMblFAjLyZXrWSOGkxnxbI JdSzw6d7rWBZnzC8KL9Vxzg9oHG/Ck26o9OgGRrM= Message-ID: Date: Tue, 8 Sep 2026 16:44:52 +0100 Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v5 0/3] x86,fs/resctrl,arm_mpam: Factor MBA parse-time conversion to be per-arch To: Reinette Chatre , Borislav Petkov Cc: x86@kernel.org, james.morse@arm.com, fenghuay@nvidia.com, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, tglx@linutronix.de, mingo@redhat.com, dave.hansen@linux.intel.com, hpa@zytor.com, corbet@lwn.net, linux-doc@vger.kernel.org, dave.martin@arm.com References: <20260709093111.367851-1-ben.horgan@arm.com> <165e7636-d7e9-4d16-aad1-657b4a9698d0@intel.com> <20260904033751.GCapo9D5ZZXWuQkIpc@fat_crate.local> <20260904173615.GOapsBjyiT7uXHd-Qc@fat_crate.local> <649aef0d-f915-4288-b3b0-4092adb783b0@intel.com> Content-Language: en-US From: Ben Horgan In-Reply-To: <649aef0d-f915-4288-b3b0-4092adb783b0@intel.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Hi Reinette, On 08/09/2026 16:35, Reinette Chatre wrote: > Hi Ben, > > On 9/7/26 3:44 AM, Ben Horgan wrote: >> Hi Boris, Reinette, >> >> On 04/09/2026 18:36, Borislav Petkov wrote: >>> On Thu, Sep 03, 2026 at 08:37:51PM -0700, Borislav Petkov wrote: >>>> Lemme have a look. >>> >>> Sashiko has comments: >>> >>> https://sashiko.dev/#/patchset/20260709093111.367851-1-ben.horgan%40arm.com >>> >>> Please address them: if valid, fix them, if not, explain why they don't need >>> to be fixed. >>> >>> Thx. >>> >> >> Regarding the first Sashiko comment. >> >> The documentation change in patch 3 includes the sentence: >> >> " >> The allocated bandwidth percentage is rounded up to the next control step available on the >> hardware. >> " >> >> Sashiko rightly objects to the "rounded up". For MPAM systems this can be up or down and we test in >> test_mpam_resctrl.c:test_percent_to_max_rounding() that it isn't too biased to rounding one way or >> the other. >> >> How about replacing "rounded up" with "rounded up or down" so that the sentence becomes: >> >> " >> The allocated bandwidth percentage is rounded up or down to the next control step available on the >> hardware. >> " >> >> What do you think? Should I respin the series with this alteration? > The change looks good to me since Intel always rounds up. By itself "rounded" may thus be deceiving. > One concern is that "next" seems to accompany "round up" to reflect forward/upward movement. > How about also replacing "next" with "nearest" or "closest"? Ok, I'll go with "closest". > > I think a respin would be most convenient to ensure the intended changes are made. Will do. Thanks, Ben > > Reinette