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=-3.9 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS 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 47EB5C4363A for ; Mon, 26 Oct 2020 19:13:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D44B72080A for ; Mon, 26 Oct 2020 19:13:51 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="Iwae16Mn"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="0LqayT//" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1792644AbgJZTNr (ORCPT ); Mon, 26 Oct 2020 15:13:47 -0400 Received: from Galois.linutronix.de ([193.142.43.55]:41840 "EHLO galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2404516AbgJZTE1 (ORCPT ); Mon, 26 Oct 2020 15:04:27 -0400 From: Thomas Gleixner DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1603739065; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=ts7OvCQ8neOrMW3H2L+mcvBibMfSxHH1JqOYqWTehYI=; b=Iwae16MnPoQQ3di3i54xsNOXPTmY4XB5Us6Q5Mcp5mPbMb+1S9sSU/O0ATGNYnP6Q4U+nk VsFQZbL2zGqCTbQDiNWroT7UwYcM8TQ7R3kAm3+x71jfSUmtjF8bbp6IUfwFc1cxpc17lZ RSrtT725UR0Hm9RVqd9Al0egcvMyZzAfkTRjEfsG2skxCbAFy1C0+hyTbMwRmQM4OtfNwt qCEsw0lFJjW2hp3xkp08nNOzv9tBreqbBzy9QA0adMF0BRpo/zpZshY/31ulS8AbnRqZID +LYxzab5w9eSxfPsdO0telgj8o3Ry3VIAduZ/4N9Y/YjR/cwm22um56qBplY7A== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1603739065; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=ts7OvCQ8neOrMW3H2L+mcvBibMfSxHH1JqOYqWTehYI=; b=0LqayT//imv88st5vOI0NJeAdqjtOjrMMYBenyRge7FnH3VcEBE6Y7XBmBg5bxzKbp4sOb yhoLkREniCc8gyBQ== To: psodagud@codeaurora.org Cc: Elliot Berman , Peter Zijlstra , "Paul E. McKenney" , Jonathan Corbet , Trilok Soni , linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org Subject: Re: [PATCH] smp: Add bootcpus parameter to boot subset of CPUs In-Reply-To: References: <1603404243-5536-1-git-send-email-eberman@codeaurora.org> <87v9f04n8r.fsf@nanos.tec.linutronix.de> Date: Mon, 26 Oct 2020 20:04:25 +0100 Message-ID: <8736204xmu.fsf@nanos.tec.linutronix.de> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Oct 26 2020 at 10:08, psodagud wrote: > Based on my understanding with maxcpus option provides, maximum no of > CPUs are brough up during the device boot up. There is a different case, > in which we want to restrict which CPUs to be brough up. Again: What for? Why? > On a system with 8 cpus, if we set maxcpus as 3, cpu0, cpu1, and cpu2 > are brough up during the bootup. For example, if we want to bring > core0, core3 and core4 current maxcpu(as 3) setting would not help us. > On some platform we want the flexibility on which CPUs to bring up > during the device bootup. bootcpus command line is helping to bring > specific CPUs and these patches are working downstream. A lot of patches work downstream by some definition of work. But that does not make an argument to bring them upstream. Thanks, tglx