From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) (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 9AA372D3A6D; Mon, 10 Nov 2025 17:31:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.176.79.56 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762795903; cv=none; b=uF1JTvYbVSJa4InNag1/S2URxfp773RdB4HUZZQzPzgrsCvc6Ew4qGC2jqze2I44rCoaTMorbbXEdJzg6ZRcTvHtdweesyFSewsENeJlqe5UAinxtZl4MKCdT0kxBDC+eKfh8tmK39X8g1qYS8+EajjMqqXT9IiNY06z6W4QmYQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762795903; c=relaxed/simple; bh=hjLldDOBYLwmC9Y21K9hHSE9sbYPZmRGkL2qIhSQFcs=; h=Date:From:To:CC:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=bRpBb2wJtqEJCAxaPC2wtFbHg2NjXUkBecaovvYOJVPcmgVLBC3i0YpvTnnDopXaEDS57RJckrCTbp8/VQh1nwhC/l1u0YeB28z9U9344VU7DE9nlORqS8Kn8fi51Hkhe69kdgEXZTElhCsA2vwhCKp670P98bxrxdUxHPBVJAo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; arc=none smtp.client-ip=185.176.79.56 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Received: from mail.maildlp.com (unknown [172.18.186.231]) by frasgout.his.huawei.com (SkyGuard) with ESMTPS id 4d4xXq462SzHnGcw; Tue, 11 Nov 2025 01:31:23 +0800 (CST) Received: from dubpeml100005.china.huawei.com (unknown [7.214.146.113]) by mail.maildlp.com (Postfix) with ESMTPS id 1921314033C; Tue, 11 Nov 2025 01:31:39 +0800 (CST) Received: from localhost (10.203.177.15) by dubpeml100005.china.huawei.com (7.214.146.113) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.36; Mon, 10 Nov 2025 17:31:37 +0000 Date: Mon, 10 Nov 2025 17:31:36 +0000 From: Jonathan Cameron To: Ben Horgan CC: , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , Zeng Heng Subject: Re: [PATCH 27/33] arm_mpam: Track bandwidth counter state for power management Message-ID: <20251110173136.000074ce@huawei.com> In-Reply-To: <20251107123450.664001-28-ben.horgan@arm.com> References: <20251107123450.664001-1-ben.horgan@arm.com> <20251107123450.664001-28-ben.horgan@arm.com> X-Mailer: Claws Mail 4.3.0 (GTK 3.24.42; x86_64-w64-mingw32) Precedence: bulk X-Mailing-List: linux-acpi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-ClientProxiedBy: lhrpeml500011.china.huawei.com (7.191.174.215) To dubpeml100005.china.huawei.com (7.214.146.113) On Fri, 7 Nov 2025 12:34:44 +0000 Ben Horgan wrote: > From: James Morse > > Bandwidth counters need to run continuously to correctly reflect the > bandwidth. > > Save the counter state when the hardware is reset due to CPU hotplug. > Add struct mbwu_state to track the bandwidth counter. Support for > tracking overflow with the same structure will be added in a > subsequent commit. > > Cc: Zeng Heng > Signed-off-by: James Morse > Signed-off-by: Ben Horgan One trivial below. Reviewed-by: Jonathan Cameron > > diff --git a/drivers/resctrl/mpam_internal.h b/drivers/resctrl/mpam_internal.h > index d8f8e29987e0..1f2b04b7703e 100644 > --- a/drivers/resctrl/mpam_internal.h > +++ b/drivers/resctrl/mpam_internal.h > @@ -91,7 +91,10 @@ struct mpam_msc { > */ > struct mutex part_sel_lock; > > - /* cfg_lock protects the msc configuration. */ > + /* > + * cfg_lock protects the msc configuration and guards against mbwu_state > + * and save and restore racing. Stray "and" that isn't needed on this second line. > + */ > struct mutex cfg_lock; >