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 BB8B6FED9F0 for ; Tue, 17 Mar 2026 17:22:31 +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=k0n9iFbOOEh19MQ+b0LGbBhs842m64zj7gWFpe7iRYQ=; b=z9RSQeC27RBDoQPTWlWwkeY7SO QjWw4Ll2xI9CZBJSJoEhqVGFRmDLm80fw06TNhdY5B+f92yXH3zNThz5BBLUvz6I2BB68TEZ7j7uq CrwGhDJZ0vvS/h2rV+XVwwA1oeXj24xhAgfiuiuy2fmSjnYPIpjg9xaOp7uBzUqm1jHW6/7GcI57c pemI/AYd2FOlE2b/mcFD6tBwbL1s2KWG7nBfldSQ1EE+tpBZGpCdXNYQN+T5NRN2PPIh+2Y78hJ1k LCF8zY7grdZzPAMhaEtqXnfR3N3vklUNwKLH+r8Qzpp00stvmbDwzdQWRK9Z66ztps8dcx4fwBrOJ 4zZtKTSA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1w2Y7f-00000006vZd-3gN1; Tue, 17 Mar 2026 17:22:27 +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 1w2Y7c-00000006vXc-16LN for linux-arm-kernel@lists.infradead.org; Tue, 17 Mar 2026 17:22:25 +0000 Received: from mail.maildlp.com (unknown [172.18.224.83]) by frasgout.his.huawei.com (SkyGuard) with ESMTPS id 4fZzKG34n7zHnGhy; Wed, 18 Mar 2026 01:21:54 +0800 (CST) Received: from dubpeml500005.china.huawei.com (unknown [7.214.145.207]) by mail.maildlp.com (Postfix) with ESMTPS id 556AB40573; Wed, 18 Mar 2026 01:22:14 +0800 (CST) Received: from localhost (10.48.149.62) by dubpeml500005.china.huawei.com (7.214.145.207) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.11; Tue, 17 Mar 2026 17:22:12 +0000 Date: Tue, 17 Mar 2026 17:22:09 +0000 From: Jonathan Cameron To: Ben Horgan CC: , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , Subject: Re: [PATCH v6 01/40] arm_mpam: Ensure in_reset_state is false after applying configuration Message-ID: <20260317172209.00001ec9@huawei.com> In-Reply-To: <20260313144617.3420416-2-ben.horgan@arm.com> References: <20260313144617.3420416-1-ben.horgan@arm.com> <20260313144617.3420416-2-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: [10.48.149.62] X-ClientProxiedBy: lhrpeml100009.china.huawei.com (7.191.174.83) To dubpeml500005.china.huawei.com (7.214.145.207) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260317_102224_456731_406A7AFE X-CRM114-Status: GOOD ( 12.27 ) 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, 13 Mar 2026 14:45:38 +0000 Ben Horgan wrote: > From: Zeng Heng > > The per-RIS flag, in_reset_state, indicates whether or not the MSC > registers are in reset state, and allows avoiding resetting when they are > already in reset state. However, when mpam_apply_config() updates the > configuration it doesn't update the in_reset_state flag and so even after > the configuration update in_reset_state can be true and mpam_reset_ris() > will skip the actual register restoration on subsequent resets. > > Once resctrl has a MPAM backend it will use resctrl_arch_reset_all_ctrls() > to reset the MSC configuration on unmount and, if the in_reset_state flag > is bogusly true, fail to reset the MSC configuration. The resulting > non-reset MSC configuration can lead to persistent performance restrictions > even after resctrl is unmounted. > > Fix by clearing in_reset_state to false immediately after successful > configuration application, ensuring that the next reset operation > properly restores MSC register defaults. > > Fixes: 09b89d2a72f3 ("arm_mpam: Allow configuration to be applied and restored during cpu online") > Signed-off-by: Zeng Heng > Acked-by: Ben Horgan > [Horgan: rewrite commit message to not be specific to resctrl unmount] > Signed-off-by: Ben Horgan Reviewed-by: Jonathan Cameron