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 411144DA0C for ; Tue, 18 Jun 2024 16:16:57 +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=1718727420; cv=none; b=rqPgNo7LOtnDzTy22L3qEn2fecbr1KQXHS+0FQymF179T4RYSv5VX0i7hVs9YLtV/1Uja04A9qV0OfRRR6Ey2JWnAX+O2iuNFIRbFF6wefjhVmLAJ11H8kscfsUlF9jcirZ/7NXYjFVO9ZrVH4nY1jh+N6D8O/AfJstF/euI1aU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718727420; c=relaxed/simple; bh=NbxLqfJp0zYtX9blzUoNH7ACgEj2ATU5B/RHkNXhUeg=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=hLshWipyKnLAn9uy5qe1+MZfJNi2tGZSTD5KG415iWWyaypE9WjkF1jEIKQpZq9voSIKAY5kbYbJ9M0SjGBy4A3VF5QByfdJz1+P+DgtwalE9PouTuP2jbN+74SexOBZX/Ev/zcQLVIpfeEwYugO9xQyfDWY61WA/vw6RYBPL/w= 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; 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 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 287C1DA7; Tue, 18 Jun 2024 09:17:22 -0700 (PDT) Received: from e133380.arm.com (e133380.arm.com [10.1.197.55]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id AE8783F6A8; Tue, 18 Jun 2024 09:16:54 -0700 (PDT) Date: Tue, 18 Jun 2024 17:16:48 +0100 From: Dave Martin To: Reinette Chatre Cc: x86@kernel.org, linux-kernel@vger.kernel.org, James Morse , Fenghua Yu , Thomas Gleixner , Ingo Molnar , Borislav Petkov , H Peter Anvin , Babu Moger , shameerali.kolothum.thodi@huawei.com, D Scott Phillips OS , carl@os.amperecomputing.com, lcherian@marvell.com, bobo.shaobowang@huawei.com, "Shaopeng Tan (Fujitsu)" , baolin.wang@linux.alibaba.com, Jamie Iles , Xin Hao , Peter Newman , dfustini@baylibre.com, amitsinght@marvell.com, David Hildenbrand , Rex Nie Subject: Re: [PATCH] x86/resctrl: Don't try to free nonexistent RMIDs Message-ID: References: <20240614160843.11006-1-Dave.Martin@arm.com> <1e3bba2e-5cf6-4a77-b92d-5c7ab1661d17@intel.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Hi Reinette, On Tue, Jun 18, 2024 at 08:43:51AM -0700, Reinette Chatre wrote: > Hi Dave, > > On 6/18/24 2:30 AM, Dave Martin wrote: > > On Mon, Jun 17, 2024 at 08:53:38AM -0700, Reinette Chatre wrote: > > > On 6/17/24 4:55 AM, Dave Martin wrote: > > > > > As it happens I tested with rdt=cmt,mbmtotal,mbmlocal,l3cat,l3cdp > > > > (though I made no effort to exercise these features other than running > > > > the selftests). I can note this in the commit if you prefer. > > > > > > hmmm ... those parameters should not be necessary unless the system > > > has those features forced off by default because of errata. Doing > > > functional testing on these systems via such enabling is fine > > > though. > > > > > > Reinette > > > > I got these kernel args from James. Apparently some of these features > > are defaulted to off by the firmware on the box I'm using, but we're not > > sure why. I haven't dug into it. > > resctrl does not provide capability to override features that the hardware > does not advertise as supporting. resctrl does sometimes force hardware > advertised features off because of errata (for example, see [1]) and the > kernel "rdt=" parameter can be used to override that. This same option also > enables administrators to ignore some features on their platforms. > > Reinette > > [1] https://lore.kernel.org/all/3aea0a3bae219062c812668bd9b7b8f1a25003ba.1503512900.git.tony.luck@intel.com/ Possibly the box in question falls under this case. I'll need to check with James and/or experiment. Either way, I don't think this impacts the tested-ness of this patch, but please shout if you have concerns. Cheers ---Dave