From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 7A44A2C08A8; Thu, 28 Aug 2025 21:44:44 +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=1756417487; cv=none; b=STkKXhhqKBtj/NxfmBxik/33bp0nIL9vfSu5YgnnZx3XCPAalzlGwqf8ITS2RHJ+qNleDs01mFmC4mf6GnvyM+zT8aVh9xSuhRMy/EmYo7IG9ZJGH3chWMIcFBPgZmlQDxXiYxCVwBJW2KMznXGPbJpFLbZJ15uoREB7moTij58= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756417487; c=relaxed/simple; bh=D0Iy2kssQWepKr3rrvAwXGm8QXT4WEE6XtWLMJ/4ooU=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=W3OHY2sHQMUvwLhcF8K4zpz8S3s1PAhBIEfCZiaXkKGDMKqX/y9dbTjkH9+258hk4IHxlta5Z3T43qKg7Gp21lr/oJMETxZg92+LXTlHvnsSa/dN/BlKEOtUqCXtDWegw7t920Ijgzu8tEmIX500lZaYKY1ZKvbgOLw+OCXamuM= 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 1B0461655; Thu, 28 Aug 2025 14:44:35 -0700 (PDT) Received: from [10.57.58.232] (unknown [10.57.58.232]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id AB5A53F738; Thu, 28 Aug 2025 14:44:42 -0700 (PDT) Message-ID: <39dccf98-41da-4c54-a200-50f367cd0147@arm.com> Date: Thu, 28 Aug 2025 22:44:41 +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 Subject: Re: [PATCH] Revert "intel_idle: Rescan "dead" SMT siblings during, initialization" To: "Rafael J. Wysocki" Cc: linux-pm , "linux-kernel@vger.kernel.org" , Artem Bityutskiy References: <724616a2-6374-4ba3-8ce3-ea9c45e2ae3b@arm.com> Content-Language: en-US From: Christian Loehle In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit On 8/28/25 20:06, Rafael J. Wysocki wrote: > On Thu, Aug 28, 2025 at 6:13 PM Rafael J. Wysocki wrote: >> >> On Thu, Aug 28, 2025 at 4:44 PM Rafael J. Wysocki wrote: >>> >>> On Thu, Aug 28, 2025 at 4:26 PM Christian Loehle >>> wrote: >>>> >>>> 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=12 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 >>>> --- >>>> 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. >>> >>> Sure, thanks for reporting this! >>> >>> Well, I think that cpuhp_smt_enable() is missing a check. It looks to >>> me like it should do the topology_is_primary_thread(cpu) check like >>> cpuhp_smt_disable(). >>> >>> I'll cut a test patch for this later. >> >> Something like the attached one, perhaps. I haven't tested it yet, >> but I'll do that later. > > Works here AFAICS, but my test system is not hybrid. Yep, on my end as well, thanks! Tested-by: Christian Loehle