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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 22B3ACA5FDD for ; Fri, 2 Oct 2026 15:16:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=LwExkX56IomKfzzcVs8YYMVfre8uAO6b9w1m8K7XkEY=; b=AbAgd9GdU7tFMHvXt4/p/j+4To +Isdl0CjHf/LZB2Z4lOMlIq9TfjfkuwN9NvBVKmQ9ML+1AIQxyICUZIDwJUPeS/0QgCN/JrOOSU+n oUbdNT+wbMOi+8tzk06ROiax0TO6BUGRjQE6NlU1kL8x32mqAcPgXurAzgQiP4kXYpBegTHRQAWf+ vPx4ZFkn3YYvLGILoCS2kmcxLYZ2vUWu1EuzQwqmFZq37H7Jol9VNBVi2x33oaJEFoNlzuFNwxkmB VUDgLVmOQHv/H0rGKRAAyIlKGeytYRupIMBjmaGJ63eoOTB0JLFvdS/t+NWhyxwtChUJnfHx4YrQO kXjWCGsg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1xCezQ-0000000BsrJ-12VI; Fri, 02 Oct 2026 15:16:00 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1xCezM-0000000Bspq-03Q2 for linux-arm-kernel@lists.infradead.org; Fri, 02 Oct 2026 15:15:59 +0000 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 20ECF1476; Fri, 2 Oct 2026 08:15:52 -0700 (PDT) Received: from [10.2.212.14] (eglon.cambridge.arm.com [10.2.212.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 638BE3F85F; Fri, 2 Oct 2026 08:15:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1790954155; bh=wxfqMJtn1W7yfkOIWwGDU+cuf258NP+En0EemreTblU=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=Yl/j+4vjl+68TN7gfciDeWp24lIKIj4Qc/A+khGDSh6B6F+kHmevE+HXub6+tePo7 +wkpQ31fwKH83cv9U9vLWqI430U8wNfxoLz8swyamgdjkdCj3Z2asBq9J+MI8uYN5z W6j4WHDsXfnA+Qdw/ZOxlLKlXhXUv2i5thyFyBG0= Message-ID: Date: Fri, 2 Oct 2026 16:15:53 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 08/12] arm_mpam: resctrl: Correct check that existing class is L3 To: Ben Horgan Cc: reinette.chatre@intel.com, fenghuay@nvidia.com, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, dave.martin@arm.com, andre.przywara@arm.com, Gavin Shan References: <20260917145617.2202986-1-ben.horgan@arm.com> <20260917145617.2202986-9-ben.horgan@arm.com> Content-Language: en-GB From: James Morse In-Reply-To: <20260917145617.2202986-9-ben.horgan@arm.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20261002_081557_116895_2DE37FCD X-CRM114-Status: GOOD ( 15.07 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi Ben, On 17/09/2026 15:56, Ben Horgan wrote: > The class used to back mbm_total_bytes can be either at the L3 or the > memory. If a platform had candidate classes at both the memory and the L3 > then, as the check for whether the existing class is L3 or not in > counter_update_class() is broken, the class that will be chosen depends on > which order the classes are considered and so the probe order. > diff --git a/drivers/resctrl/mpam_resctrl.c b/drivers/resctrl/mpam_resctrl.c > index 9d223057953a..b825bd90d4bd 100644 > --- a/drivers/resctrl/mpam_resctrl.c > +++ b/drivers/resctrl/mpam_resctrl.c > @@ -1076,7 +1076,7 @@ static void counter_update_class(enum resctrl_event_id evt_id, > struct mpam_class *existing_class = mpam_resctrl_counters[evt_id].class; > > if (existing_class) { > - if (class->level == 3) { > + if (existing_class->level == 3) { > pr_debug("Existing class is L3 - L3 wins\n"); > return; > } Heh, the debug message strong hints at how that was supposed to work! Reviewed-by: James Morse Thanks, James