From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D0FF6606A31C for ; Mon, 9 Nov 2026 08:22:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.a=rsa-sha256 header.s=bombadil.20210309 header.b=ahVfjOKp; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20260707 header.b=fzcxw7qn 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:References:To:Subject:From:MIME-Version:Date: Message-ID:Reply-To:Cc:Content-ID:Content-Description:Resent-Date:Resent-From :Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Unsubscribe-Post: List-Owner; bh=VcAkY3YiPTQFVieeDjubnbkf41BaBANgAAkiKJvWm2w=; b=ahVfjOKpwldLWG b+qq0m0UsJxkoMQCIE0gGWc7l+bTQGACpq6WCYdf9YB5/9nlGto8MOihnIh8/HML1kwJObFyAaSOJ FSzx1lDRcTlkvSjbDgUvJGKHTyzqZlCe360CKSG5onIpmRJrrl/3/n4B8LEGiTRUkujWrR4GDpkPM bJlLNvm0xLgeAWBtZE8nxiyPXUetxb56MUzFgFph1XDtMVsPuSaUu1OF7yvsTV/KUWGMQYxnpICIs B/ty1w8XqdPeTpsqYYreIJjUoj2iAHavJ5hQGFemCQaBnY9QHNFljA229kwW9t42LzoKHKdbrz9Mj FMJWeI0bbPeW+zgw2Lsw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.100.1 #2 (Red Hat Linux)) id 1xQKeA-000000002cH-3Ijb; Mon, 09 Nov 2026 08:22:34 +0000 Received: from mail-dl2-x07.google.com ([2607:f8b0:4864:38::7]) by bombadil.infradead.org with esmtps (Exim 4.100.1 #2 (Red Hat Linux)) id 1xQKe5-000000002ao-1Ism for linux-arm-kernel@lists.infradead.org; Mon, 09 Nov 2026 08:22:33 +0000 Received: by mail-dl2-x07.google.com with SMTP id a92af1059eb24-13985f8229aso678466c88.1 for ; Mon, 09 Nov 2026 00:22:29 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20260707; t=1794212548; x=1794817348; darn=lists.infradead.org; h=content-transfer-encoding:content-type:in-reply-to:content-language :references:to:subject:from:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to:content-type; bh=VcAkY3YiPTQFVieeDjubnbkf41BaBANgAAkiKJvWm2w=; b=fzcxw7qndX4pH8E46FZxWHbLpsoirYsYb/YbNhcp2MmSrcUCNAtFFeVZ8knXZnL9Yu br7CY5Eock4DrS8tDVpgXaRujXGDzHyte7OgeV2/PO26k2jkuflUhGF8LiHlfSWwKcBz J/UUJLG+tddcQULVAdz6XxgkaTpHOPRUMb+0iQ0Zt+u6U0ff7Zf/KgTP1oyX5aWZwvjN 8qpT9f629GF58ZO8SHmhpzMESvmxCSPHHFvxI73YYxTgZXd9cPWUPeG488y9nrLUex57 gR3p+DQHwXz99dl6XOfKBZbm36pqkcmFsbtnLJidi+Oz9B1ogwjdrWNQPII8DaU9Xiy5 nUlg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1794212548; x=1794817348; h=content-transfer-encoding:content-type:in-reply-to:content-language :references:to:subject:from:user-agent:mime-version:date:message-id :x-gm-gg:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to:content-type; bh=VcAkY3YiPTQFVieeDjubnbkf41BaBANgAAkiKJvWm2w=; b=O6RaBSIO5FXMd+oVfpKiHZqyHuQ7dl+xpuUF1sFPPYG5weaIzIq8ZKZZVytJAUwc7s KH3SKN/wyYdSP5EToq//vd/KAnw140Cdy//nGZ6VmoSAf9Os12msXs+KCnKDNT8/4nmR c/v1yERze3kGjN6s6RQCwLSb99AMCwO+7OOyN3Dl1d9mdm6pgU06xWP/GzZNq9plJsxF vTJL8VGjTnxSknjEJSXWFfzdn/3o05+k1LhMjzh9RbN6Ol+QyqSr9puguLWhDHfSrmeH XqeS00zZ/c7I287ZerglSi86DH0OSvwZ6VIdU0oNl19bOUd29VjM547kA0eSHfeyfJ/E 8UwQ== X-Forwarded-Encrypted: i=1; AL+hErH1p3/KL3iRB96tUUIjxU/WiV+jWs1uzeT1nFirNrVh5J7ZFWAhIG+xDEbxCPF1cMw6BXLLuUaabspvJ5hL8h3L@lists.infradead.org X-Gm-Message-State: APuU4Z+UEG229bZk82iDKXtZnNe/RneJoU8onfhGZUb48JRQmHIpNAEz GZqLB2iOgrY7Thk4mtbCtSwSZQ9XAHxI7FO/u5bj2S5V6h1cj9u2ZOLjWYhFlkYmR78= X-Gm-Gg: AYBFou0rV9DkDQBGJn9dRwcsQO4Q7Z+NUW78ubftQFhh8rT7vWRYS148xmVDbe3fR9C sRU67Rbl6l/4QghSwUVLtvqA4xkewDXHnQuHYWsraX3Gm4BDKsFh8qp7DqeaeRusQuzujrcqhvS AWWxRbojongQodALwMnLRE3cC0e8FrGN/7y59NnGvPDsJT4OCJilfnd+ZPgGB9Jlzz5P/2A9Tzv PRWGv1ZtcaueMKc19EGa6Ia1u0Xl939bBF6KH6Oa1rT2k8kCrbpz18P/RrvbcU0dOS0lHIEZVYO trBTylJBxRc+fzkFCozg2HrZ+teRtK48VUblJFEp/sPXSUbecB4UGlAULJ6P23eTYVP93m1cx/4 dVvPYqF8n6LfahewqWnAabYlgcNe2inmu8+MNvR/sNWjzoJZhPzH0fKHeX4A9tIQrQFOfIvInsR X7QAbR5hdHKIzE1CSBC6ZezFicztMF6yD1ucEDvPmacP+pLfyLNt3Ly8wh2+qhwqyeP6xbsEJ0/ ziaw0byFFRpnLgRM/7lQa2jwdZUCtCDpsvXiRtBxRmuzUuWAR+v+mCoNyqFCs/FeIiVG39aGnoS SzBlePOU6r4XDwYyLUBW4t/IhClxzyHK6Salfa0= X-Received: by 2002:a05:6a20:258e:b0:3e2:100b:1043 with SMTP id adf61e73a8af0-3eed3c6c6e1mr3218263637.42.1794207088842; Sun, 08 Nov 2026 22:51:28 -0800 (PST) Received: from [100.125.153.207] ([139.159.170.67]) by smtp.gmail.com with ESMTPSA id 41be03b00d2f7-cdb9677c58dsm1220517a12.3.2026.11.08.22.51.25 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sun, 08 Nov 2026 22:51:28 -0800 (PST) Message-ID: Date: Mon, 9 Nov 2026 14:51:22 +0800 X-Archived-By: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird From: Jinjie Ruan Subject: Re: [PATCH] arm_mpam: resctrl: Leave CDP off when there are too few PARTIDs To: Ben Horgan , Jinjie Ruan , james.morse@arm.com, reinette.chatre@intel.com, fenghuay@nvidia.com, tan.shaopeng@jp.fujitsu.com, jic23@kernel.org, zengheng4@huawei.com, gshan@redhat.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org References: <20261031025257.1540228-1-ruanjinjie@huawei.com> <750c9d05-94f8-4936-a824-5ccbed1d13ed@huawei.com> Content-Language: en-US In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20261109_002229_499857_227D67F5 X-CRM114-Status: GOOD ( 22.76 ) X-Spam-Score: -1.9 (-) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" X-Spam-Status: No, score=-14.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FREEMAIL_FORGED_FROMDOMAIN, FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=4.0.1 X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 在 2026/11/6 19:34, Ben Horgan 写道: > Hi Jinjie, > Hi Ben, > On 06/11/2026 08:35, Jinjie Ruan wrote: >> Hi Ben, >> >> Is this modification okay? > > Yes it's ok but there is more we can do here. Sashiko has raised a bug that points out we don't take > into account whether or not a resource is cdp_capable or not [1]. > > This leads to an additional check along the lines of: > > if (enable && (!the_res.alloc_capable || !the_res.cdp_capable)) > return -EINVAL; Ok, I will fix it together. > > On a process note, it would helpful to me for reviewing and later on when collecting the patches > together if you could put related patches together in a series. In the case of this patch it it is > solving a cdp related problem, as is your patch "arm_mpam: resctrl: Limit num_rmids to the CLOSIDs > in use". fs/resctrl patches though should be kept separately unless there is a particular reason why > they should be in a series with MPAM patches, e.g. new resctrl_arch_ helpers and such like. OK, I will send them in a patch set for the mpam cdp patches. Best Regards, Jinjie > > [1] https://sashiko.dev/#/bug/linux-05c19551-0bba-4a06-aa2c-3c90fab5853d > > Thanks, > > Ben > >> >> 在 2026/10/31 10:52, Jinjie Ruan 写道: >>> Enabling CDP requires at least 2 PARTIDs. If there are too few PARTIDs, >>> resctrl_arch_set_cdp_enabled() returns -EINVAL, but only after it has >>> recorded CDP as enabled, halved the monitor count and turned off the >>> mbw_max MBA control. resctrl then believes CDP is off, which leaves the >>> two sides out of step and the halved monitor count and the missing MBA >>> control are not undone. >>> >>> Check the PARTID limit before anything is changed so a failed enable has >>> no effect. >>> >>> Fixes: 6789fb99282c ("arm_mpam: resctrl: Add CDP emulation") >>> Signed-off-by: Jinjie Ruan >>> --- >>> RFC v2 -> v1: >>> - Check mpam_partid_max ahead and The partid_d/partid_i determination >>> remains in place. >>> - Update the commit message as Ben suggested. >>> --- >>> drivers/resctrl/mpam_resctrl.c | 6 +++--- >>> 1 file changed, 3 insertions(+), 3 deletions(-) >>> >>> diff --git a/drivers/resctrl/mpam_resctrl.c b/drivers/resctrl/mpam_resctrl.c >>> index 5468367776e2..aa3b3a093857 100644 >>> --- a/drivers/resctrl/mpam_resctrl.c >>> +++ b/drivers/resctrl/mpam_resctrl.c >>> @@ -210,6 +210,9 @@ int resctrl_arch_set_cdp_enabled(enum resctrl_res_level rid, bool enable) >>> if (enable) >>> pr_warn("CDP is an expert feature and may cause MPAM to malfunction.\n"); >>> >>> + if (enable && mpam_partid_max < 1) >>> + return -EINVAL; >>> + >>> /* >>> * resctrl_arch_set_cdp_enabled() is only called with enable set to >>> * false on error and unmount. >>> @@ -239,9 +242,6 @@ int resctrl_arch_set_cdp_enabled(enum resctrl_res_level rid, bool enable) >>> mpam_resctrl_controls[RDT_RESOURCE_MBA].resctrl_res.alloc_capable = true; >>> >>> if (enable) { >>> - if (mpam_partid_max < 1) >>> - return -EINVAL; >>> - >>> partid_d = resctrl_get_config_index(RESCTRL_RESERVED_CLOSID, CDP_DATA); >>> partid_i = resctrl_get_config_index(RESCTRL_RESERVED_CLOSID, CDP_CODE); >>> } >> >