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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS 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 24604C43441 for ; Sun, 18 Nov 2018 18:21:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EDC5A20817 for ; Sun, 18 Nov 2018 18:21:34 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org EDC5A20817 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linutronix.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727274AbeKSEma (ORCPT ); Sun, 18 Nov 2018 23:42:30 -0500 Received: from Galois.linutronix.de ([146.0.238.70]:36910 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727141AbeKSEma (ORCPT ); Sun, 18 Nov 2018 23:42:30 -0500 Received: from p4fea46ac.dip0.t-ipconnect.de ([79.234.70.172] helo=nanos) by Galois.linutronix.de with esmtpsa (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256) (Exim 4.80) (envelope-from ) id 1gORhF-0003HB-Bj; Sun, 18 Nov 2018 19:21:25 +0100 Date: Sun, 18 Nov 2018 19:21:24 +0100 (CET) From: Thomas Gleixner To: Qian Cai cc: akpm@linux-foundation.org, longman@redhat.com, yang.shi@linux.alibaba.com, arnd@arndb.de, linux-kernel@vger.kernel.org Subject: Re: [PATCH] debugobjects: add a new Kconfig for POOL_SIZE In-Reply-To: <20181118082255.1275-1-cai@gmx.us> Message-ID: References: <20181118082255.1275-1-cai@gmx.us> User-Agent: Alpine 2.21 (DEB 202 2017-01-01) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Qian, On Sun, 18 Nov 2018, Qian Cai wrote: > The current value of ODEBUG_POOL_SIZE is not big enough for large memory > systems with timer or/and workqueue objects because during the early > boot, timer objects needs at least the size equals to > > No. CPUs x 2 (worker pool) > > start_kernel > workqueue_init_early > init_worker_pool > init_timer_key > debug_object_init > > puls, No. CPUs > > start_kernel > sched_init > hrtimer_init > debug_object_init > > Then, workqueue objects requires even more, > > No. CPUs x 2 (worker pool) x 6 (workqueue) > > start_kernel > workqueue_init_early > __alloc_workqueue_key > alloc_workqueue > init_pwq > debug_object_init > > plus, No, CPUs x 2 (worker pool) > > start_kernel > perf_event_init > __init_srcu_struct > init_srcu_struct_fields > __init_work > debug_object_init > > As the results, systems have 60+ CPUs with both timer and workqueue > objects enabled could trigger "ODEBUG: Out of memory. ODEBUG disabled". > > Hence, add a new Kconfig option so users could adjust ODEBUG_POOL_SIZE > accordingly if either timer or workqueue objects are selected. why do we need a config option, when the required number can be deduced already from the active CONFIG_DEBUG_OBJECTS_* and NR_CPUS? Thanks, tglx