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 X-Spam-Level: X-Spam-Status: No, score=-2.5 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0C098ECDE20 for ; Wed, 11 Sep 2019 16:06:41 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id D708620838 for ; Wed, 11 Sep 2019 16:06:40 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="owAbChwf" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D708620838 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender:Content-Type: Content-Transfer-Encoding:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:Date:Message-ID:From: References:To:Subject:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=JAJHZTSt7JPa35ybIGKWWmc0BuQHaemWk2uLPN9Pdn8=; b=owAbChwf0wlvUdEFpaNrLqfIQ 7SE9msTLxlEsJ5qGlNme4Td54PK0i38njrE1RWtsJ96wlvgM30kmmAhP7plmCn+xs+L3ZQzM0jdKn mTUUzWmnek157EwU08PRoPETuTFdqJ/apJKQDCys89oLsCmE7FKgq9foVkgOQnRs/9Zgo306A2ifI pLS7tYIn9bPOUOKCh8AxPRm8qiR049Ik3dmnTbBpiemQLBj29yXnDRRESdaPBLAb+A5s2sbNeNePG BpaZgzBQ3pIV7BWDMvjrn70I+wtcR5tTzGLTTBz3OYSNTZnQIEzAJX8GWiSarEfTnYZCePsMdtR7m JoQMd3Wpw==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.2 #3 (Red Hat Linux)) id 1i858d-0002oX-Iw; Wed, 11 Sep 2019 16:06:35 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.92.2 #3 (Red Hat Linux)) id 1i858a-0002na-Bc for linux-arm-kernel@lists.infradead.org; Wed, 11 Sep 2019 16:06:33 +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 E265728; Wed, 11 Sep 2019 09:06:28 -0700 (PDT) Received: from [10.37.13.2] (unknown [10.37.13.2]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 2251F3F67D; Wed, 11 Sep 2019 09:06:27 -0700 (PDT) Subject: Re: offline CPUs shown in sysfs core_siblings mask To: Brice Goglin References: From: James Morse Message-ID: <4568af7d-724e-5ee7-3ba1-87a5db662447@arm.com> Date: Wed, 11 Sep 2019 17:06:24 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: Content-Language: en-US X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190911_090632_437992_573B2E7C X-CRM114-Status: GOOD ( 12.59 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Jeremy Linton , linux-arm-kernel@lists.infradead.org Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi Brice, (CC: +Jeremy) On 9/11/19 2:23 PM, Brice Goglin wrote: > We have a report from a user of hwloc/lstopo on ThunderX2 that complains > that offline CPUs are shown in sysfs cpu core_siblings files. Hmmm, this doesn't happen on my TX2, running mainline: root@eglon:/sys/devices/system/cpu# cat cpu1/topology/core_siblings 00000000,00000000,00000000,00000000,ffffffff,ffffffff,ffffffff,ffffffff root@eglon:/sys/devices/system/cpu# echo 0 > cpu0/online root@eglon:/sys/devices/system/cpu# cat cpu1/topology/core_siblings 00000000,00000000,00000000,00000000,ffffffff,ffffffff,ffffffff,fffffffe root@eglon:/sys/devices/system/cpu# echo 1 > cpu0/online root@eglon:/sys/devices/system/cpu# cat cpu1/topology/core_siblings 00000000,00000000,00000000,00000000,ffffffff,ffffffff,ffffffff,ffffffff > Only 8 online logicial CPUs, but 56 are shown in these masks. This is on > RHEL7 with a kernel 4.14.0-115.2.2.el7a.aarch64 but I couldn't find any > significant change in Linux git. Could you try a recent mainline kernel? Does your system have an ACPI PPTT table? (I assume its ACPI) Prior to the ACPI PPTT table handling, it wasn't possible for an arm64 ACPI system to know about packages and threads. > I guess thread_siblings has the same behavior but I couldn't test it. (this would depend on the firmware table too) Thanks, James _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel