From mboxrd@z Thu Jan 1 00:00:00 1970 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.subspace.kernel.org (Postfix) with ESMTPS id 5663654654; Tue, 9 Sep 2025 04:11:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.133 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757391082; cv=none; b=sGhdTaCrDUjbBNFvZTinYumrFWnwTPZsJKbn8PgE6dGO7efKw5JCq3HBLDiavX0DnDiNdTLKDCMgiAAWTyTr2WZ6LhgziaxDs0n5WKjL+mBpkPynM/N5tS7134TWTLsziRUU17U92jrxVfLLVbeEM1ryBPZiRIT5dQyywgmzZKk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757391082; c=relaxed/simple; bh=o80n4ExUoBAJUnTE9XsmrZlYvocq1FJTlQI4X2crCJM=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=N06MrD8K0DG7T2FVxAUrNLvbWhyT9veKFmCQ/Sncte9X8sEif0XXeA+q9o3k3DBjtFeMxeT1T7EIYgtwDy0nQ2ZbBceaqWc+D8YvvP+rHLdbr6uuHcQaweFGd7OZ9m3GcpF4FFHDYjuAxdlywZZpqr15EpK6amCaBU1k9i9PGuk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=K49EFCyf; arc=none smtp.client-ip=198.137.202.133 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="K49EFCyf" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=Content-Transfer-Encoding: Content-Type:In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date: Message-ID:Sender:Reply-To:Content-ID:Content-Description; bh=H+Mt0obVe+OHMg9mtzsKgB8kbdimq6iDYKrqcoNyusY=; b=K49EFCyfJCBdULh6YgKLpruaW1 nxEQBusnHzafOmNDLfmKbUUs4c/GEAxqA44xLHdxfZ6eRp0PjSplqlQdYgfO22DNza++WZ726bKt5 Qy03D7XgBLDX1AoXtVha0T3f8jlZ4vl75tBRZzjM7ebrwxx1fACZwjEuutDBPuBeHYqESFFQbk7NM 5MI52+YgIwPBHN+oO/45Dr/+1mGSHyvQK9HUhml69clnXhog4/3r9L5nAxUE7IWOwXCcuFcJImaz5 rqF6Jq/hVRvExIpQa6fVqsryZd+pvoTdMiEnhToqiJZ3oUni7D89n7kAKByh70iIrAklYdpT2lSy5 pTqujRHw==; Received: from [50.53.25.54] (helo=[192.168.254.17]) by bombadil.infradead.org with esmtpsa (Exim 4.98.2 #2 (Red Hat Linux)) id 1uvphN-0000000487l-0Nke; Tue, 09 Sep 2025 04:11:17 +0000 Message-ID: <94f08403-31f5-43ee-871d-5e0ebcfd3b6c@infradead.org> Date: Mon, 8 Sep 2025 21:11:16 -0700 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 03/12] rseq: Provide static branch for time slice extensions To: K Prateek Nayak , Thomas Gleixner , LKML Cc: Mathieu Desnoyers , Peter Zijlstra , "Paul E. McKenney" , Boqun Feng , Jonathan Corbet , Prakash Sangappa , Madadi Vineeth Reddy , Steven Rostedt , Sebastian Andrzej Siewior , Arnd Bergmann , linux-arch@vger.kernel.org References: <20250908225709.144709889@linutronix.de> <20250908225752.744169647@linutronix.de> <0f28cc54-1f84-4f28-bd61-ee9e0b9d0d0c@amd.com> Content-Language: en-US From: Randy Dunlap In-Reply-To: <0f28cc54-1f84-4f28-bd61-ee9e0b9d0d0c@amd.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 9/8/25 8:10 PM, K Prateek Nayak wrote: > Hello Thomas, > > On 9/9/2025 4:29 AM, Thomas Gleixner wrote: >> +#ifdef CONFIG_RSEQ_SLICE_EXTENSION >> +DEFINE_STATIC_KEY_TRUE(rseq_slice_extension_key); >> + >> +static int __init rseq_slice_cmdline(char *str) >> +{ >> + bool on; >> + >> + if (kstrtobool(str, &on)) >> + return -EINVAL; >> + >> + if (!on) >> + static_branch_disable(&rseq_slice_extension_key); >> + return 0; > > I believe this should return "1" signalling that the cmdline was handled > correctly to avoid an "Unknown kernel command line parameters" message. Good catch. I agree. Thanks. >> +} >> +__setup("rseq_slice_ext=", rseq_slice_cmdline); >> +#endif /* CONFIG_RSEQ_SLICE_EXTENSION */ >> > -- ~Randy