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 D12DECCF9E3 for ; Mon, 10 Nov 2025 17:31:51 +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:MIME-Version:References:In-Reply-To:Message-ID:Subject:CC:To: From:Date:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=UD6D1rar62jsL1zHC1IEq519p2xAp9IZhJ41iuxrkDg=; b=H53Ejsjq422cwvGMaUvXO8554B DM/BXtL+m+Bbnm2cO/0jEEHi/VlO9icqe0WEiSiQozBQtQ6qOP0WE+AXMMRiERkpSZfKDG8xzy2jX k6xCSsUFdUacn6p5WAH1ChuwfpUjVgUZfxy3rY0FSonlgHrLYytSTdWQVVc1B4dKCMTbi+nRTEZlq +bqL8HlarzW7cCoX5BK0OGy6hl9e/N7PZY0XfzrOsZ9WODb8Iwjhf9fZylL0MDGjKvZP+B1C/hzEl xHhDx/cqbZiIPLdCOz47Cz+9X5sczcZ2nm674lQ/a4feK7nQ6FeUcX2okE298QInX8c/s4YWp2Jmk RMjBb9Tw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vIVk1-00000005uIj-444G; Mon, 10 Nov 2025 17:31:45 +0000 Received: from frasgout.his.huawei.com ([185.176.79.56]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1vIVjx-00000005uHL-2l2S for linux-arm-kernel@lists.infradead.org; Mon, 10 Nov 2025 17:31:44 +0000 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) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.203.177.15] X-ClientProxiedBy: lhrpeml500011.china.huawei.com (7.191.174.215) To dubpeml100005.china.huawei.com (7.214.146.113) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20251110_093143_033116_D39CBFE8 X-CRM114-Status: GOOD ( 13.68 ) 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 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; >