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=-11.1 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, NICE_REPLY_A,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham 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 08621C433E2 for ; Tue, 15 Sep 2020 19:24:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7AE1F206B2 for ; Tue, 15 Sep 2020 19:24:54 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="bYn0ZXkl" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727953AbgIOTYv (ORCPT ); Tue, 15 Sep 2020 15:24:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52218 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727697AbgIOTYv (ORCPT ); Tue, 15 Sep 2020 15:24:51 -0400 Received: from merlin.infradead.org (merlin.infradead.org [IPv6:2001:8b0:10b:1231::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9A62FC06178A; Tue, 15 Sep 2020 12:24:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.20170209; h=Content-Transfer-Encoding:Content-Type: In-Reply-To:MIME-Version:Date:Message-ID:From:References:Cc:To:Subject:Sender :Reply-To:Content-ID:Content-Description; bh=V+4IkKNpJfe7Iudt9BhXz9NYz+CKaO32K4RDpUC5uiY=; b=bYn0ZXkls+FF4erz0dicshnWJN ZjBlmjvXNtOq1Gp2592t28LNepFk4VvHrMRmxGz9QN1RAZPAxnoaVGaqUKrctSedmclLtQIAi1fj7 Xn0KKiYnGZGWPAo99gdMWFaWMzP6/hNzMCUnczx8sryfNQUm5SIuK5DKbVDA4n0jtQO7oR8Lk2dyo 9R5kve+M+hco+uLo7BVHuTJQuthYcncHtx06xWiRkrM7MrAE0LW/VHc6VaEbQLpWz02649Os5l/aI oI7yGL4tTxN/CenXjnl1ljUS+syxwfyKTkE0TQE9s8Dr5JR9PqhkA/HgkSRLUYBrlxuZ/b+7ZP7Jk qKrONyIA==; Received: from [2601:1c0:6280:3f0::19c2] by merlin.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1kIGZ8-0007KI-88; Tue, 15 Sep 2020 19:24:34 +0000 Subject: Re: [PATCH v11 4/5] locking/qspinlock: Introduce starvation avoidance into CNA To: Alex Kogan , linux@armlinux.org.uk, peterz@infradead.org, mingo@redhat.com, will.deacon@arm.com, arnd@arndb.de, longman@redhat.com, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, tglx@linutronix.de, bp@alien8.de, hpa@zytor.com, x86@kernel.org, guohanjun@huawei.com, jglauber@marvell.com Cc: steven.sistare@oracle.com, daniel.m.jordan@oracle.com, dave.dice@oracle.com References: <20200915180535.2975060-1-alex.kogan@oracle.com> <20200915180535.2975060-5-alex.kogan@oracle.com> From: Randy Dunlap Message-ID: <8019917d-5e8e-e03d-583c-6809dee7a5c2@infradead.org> Date: Tue, 15 Sep 2020 12:24:26 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.12.0 MIME-Version: 1.0 In-Reply-To: <20200915180535.2975060-5-alex.kogan@oracle.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-arch-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-arch@vger.kernel.org Hi, Entries in the kernel-parameters.txt file should be kept in alphabetical order mostly (there are a few exceptions where related options are kept together). On 9/15/20 11:05 AM, Alex Kogan wrote: > Keep track of the time the thread at the head of the secondary queue > has been waiting, and force inter-node handoff once this time passes > a preset threshold. The default value for the threshold (10ms) can be > overridden with the new kernel boot command-line option > "numa_spinlock_threshold". The ms value is translated internally to the > nearest rounded-up jiffies. > > Signed-off-by: Alex Kogan > Reviewed-by: Steve Sistare > Reviewed-by: Waiman Long > --- > .../admin-guide/kernel-parameters.txt | 9 ++ > kernel/locking/qspinlock_cna.h | 95 ++++++++++++++++--- > 2 files changed, 92 insertions(+), 12 deletions(-) > > diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt > index 51ce050f8701..73ab23a47b97 100644 > --- a/Documentation/admin-guide/kernel-parameters.txt > +++ b/Documentation/admin-guide/kernel-parameters.txt > @@ -3363,6 +3363,15 @@ > Not specifying this option is equivalent to > numa_spinlock=auto. > > + numa_spinlock_threshold= [NUMA, PV_OPS] > + Set the time threshold in milliseconds for the > + number of intra-node lock hand-offs before the > + NUMA-aware spinlock is forced to be passed to > + a thread on another NUMA node. Valid values > + are in the [1..100] range. Smaller values result > + in a more fair, but less performant spinlock, > + and vice versa. The default value is 10. > + > cpu0_hotplug [X86] Turn on CPU0 hotplug feature when > CONFIG_BOOTPARAM_HOTPLUG_CPU0 is off. > Some features depend on CPU0. Known dependencies are: This new entry and numa_spinlock from patch 3/5 should go between these other 2 NUMA entries: numa_balancing= [KNL,X86] Enable or disable automatic NUMA balancing. Allowed values are enable and disable numa_zonelist_order= [KNL, BOOT] Select zonelist order for NUMA. 'node', 'default' can be specified This can be set from sysctl after boot. See Documentation/admin-guide/sysctl/vm.rst for details. Oooh, that cpu0_hotplug entry is way out of place. I'll send a patch for that. thanks. -- ~Randy