From nobody Fri Oct 3 15:34:25 2025 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id AF86A21CA02; Thu, 28 Aug 2025 14:26:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756391162; cv=none; b=fgSJOPENt3OBTx8I5CxdMS9nJDI85CzOGkGeX/+Bc9ScqzRayGZ0RrU/cMS0SsdRNdaFFuC2igakx8pvdDyYTqyKmdlwEQXmBU4WK8diy/ewN03c92Ia8N3W4dzdf5irimpCOg/4zDdpu0vqPhmj25kjByHOe9so1zTMcf647JE= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756391162; c=relaxed/simple; bh=tVpT6XjIyI1FQCJlEk+4ojWuzvl5wVAREanoCFg6vgA=; h=Message-ID:Date:MIME-Version:To:From:Subject:Content-Type; b=VXtwv9pYejjuLeCGk0qVJPg1jit5o7rf46C2RRh3X2u5/BoGvGnjtthv9ZnnphTsH4IlkbV2k0ROvDANVZchN09AqgYOKhRNmDXkpAlEK7TwWBJH8srJaQAFF2PikIiR0UeJZa7r63e45SX7tLJrmyfEF3cRWA/6WmZdmxBw+O0= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com 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 B644F1688; Thu, 28 Aug 2025 07:25:51 -0700 (PDT) Received: from [10.1.37.80] (e127648.arm.com [10.1.37.80]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 763CE3F694; Thu, 28 Aug 2025 07:25:59 -0700 (PDT) Message-ID: <724616a2-6374-4ba3-8ce3-ea9c45e2ae3b@arm.com> Date: Thu, 28 Aug 2025 15:25:58 +0100 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Content-Language: en-US To: "Rafael J. Wysocki" , linux-pm , "linux-kernel@vger.kernel.org" , Artem Bityutskiy From: Christian Loehle Subject: [PATCH] Revert "intel_idle: Rescan "dead" SMT siblings during, initialization" Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" This reverts commit a430c11f401589a0f4f57fd398271a5d85142c7a. Calling arch_cpu_rescan_dead_smt_siblings() in intel_idle_init with boot parameter nosmt and maxcpus active hotplugged boot-offline CPUs in (and leave them online) which weren't supposed to be online. With the revert and nosmt and maxcpus=3D12 on a raptor lake: cpu online capacity cpu0 1 1009 cpu1 0 - cpu2 1 1009 cpu3 0 - cpu4 1 1009 cpu5 0 - cpu6 1 1009 cpu7 0 - cpu8 1 1024 cpu9 0 - cpu10 1 1024 cpu11 0 - cpu12 1 1009 cpu13 0 - cpu14 1 1009 cpu15 0 - cpu16 1 623 cpu17 1 623 cpu18 1 623 cpu19 1 623 cpu20 0 - cpu21 0 - cpu22 0 - cpu23 0 - Previously: cpu online capacity cpu0 1 1009 cpu1 0 - cpu2 1 1009 cpu3 0 - cpu4 1 1009 cpu5 0 - cpu6 1 1009 cpu7 0 - cpu8 1 1024 cpu9 0 - cpu10 1 1024 cpu11 0 - cpu12 1 1009 cpu13 0 - cpu14 1 1009 cpu15 0 - cpu16 1 623 cpu17 1 623 cpu18 1 623 cpu19 1 623 cpu20 1 623 cpu21 1 623 cpu22 1 623 cpu23 1 623 Signed-off-by: Christian Loehle Tested-by: Christian Loehle --- Rafael, I don't immediately see how to fix this properly so I won't try to, feel free to treat this as a bug report. drivers/idle/intel_idle.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c index 91a7b7e7c0c8..a9c58395a425 100644 --- a/drivers/idle/intel_idle.c +++ b/drivers/idle/intel_idle.c @@ -2507,8 +2507,6 @@ static int __init intel_idle_init(void) pr_debug("Local APIC timer is reliable in %s\n", boot_cpu_has(X86_FEATURE_ARAT) ? "all C-states" : "C1"); =20 - arch_cpu_rescan_dead_smt_siblings(); - return 0; =20 hp_setup_fail: --=20 2.34.1