From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751957AbbC1E2k (ORCPT ); Sat, 28 Mar 2015 00:28:40 -0400 Received: from mail-oi0-f53.google.com ([209.85.218.53]:33708 "EHLO mail-oi0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750976AbbC1E2j (ORCPT ); Sat, 28 Mar 2015 00:28:39 -0400 MIME-Version: 1.0 In-Reply-To: <20150327120240.GC23123@twins.programming.kicks-ass.net> References: <359c926bc85cdf79650e39f2344c2083002545bb.1427347966.git.viresh.kumar@linaro.org> <20150326131822.fce6609efdd85b89ceb3f61c@linux-foundation.org> <20150327091613.GE27490@worktop.programming.kicks-ass.net> <20150327093023.GA32047@worktop.ger.corp.intel.com> <20150327120240.GC23123@twins.programming.kicks-ass.net> Date: Sat, 28 Mar 2015 09:58:38 +0530 Message-ID: Subject: Re: [RFC] vmstat: Avoid waking up idle-cpu to service shepherd work From: Viresh Kumar To: Peter Zijlstra Cc: Christoph Lameter , Andrew Morton , Johannes Weiner , Linaro Kernel Mailman List , Linux Kernel Mailing List , vinmenon@codeaurora.org, shashim@codeaurora.org, Michal Hocko , Mel Gorman , dave@stgolabs.net, Konstantin Khlebnikov , Linux Memory Management List , Suresh Siddha , Thomas Gleixner Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 27 March 2015 at 17:32, Peter Zijlstra wrote: > What's not clear to me is why that thing is allocated at all, AFAICT > something like: > > static DEFINE_PER_CPU(struct tvec_base, tvec_bases); > > Should do the right thing and be much simpler. Does this comment from timers.c answers your query ? /* * This is for the boot CPU - we use compile-time * static initialisation because per-cpu memory isn't * ready yet and because the memory allocators are not * initialised either. */ From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-oi0-f46.google.com (mail-oi0-f46.google.com [209.85.218.46]) by kanga.kvack.org (Postfix) with ESMTP id 9A03A6B0038 for ; Sat, 28 Mar 2015 00:28:39 -0400 (EDT) Received: by oifl3 with SMTP id l3so91724113oif.0 for ; Fri, 27 Mar 2015 21:28:39 -0700 (PDT) Received: from mail-oi0-f45.google.com (mail-oi0-f45.google.com. [209.85.218.45]) by mx.google.com with ESMTPS id h3si2290819obz.71.2015.03.27.21.28.38 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 27 Mar 2015 21:28:38 -0700 (PDT) Received: by oifl3 with SMTP id l3so91724035oif.0 for ; Fri, 27 Mar 2015 21:28:38 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <20150327120240.GC23123@twins.programming.kicks-ass.net> References: <359c926bc85cdf79650e39f2344c2083002545bb.1427347966.git.viresh.kumar@linaro.org> <20150326131822.fce6609efdd85b89ceb3f61c@linux-foundation.org> <20150327091613.GE27490@worktop.programming.kicks-ass.net> <20150327093023.GA32047@worktop.ger.corp.intel.com> <20150327120240.GC23123@twins.programming.kicks-ass.net> Date: Sat, 28 Mar 2015 09:58:38 +0530 Message-ID: Subject: Re: [RFC] vmstat: Avoid waking up idle-cpu to service shepherd work From: Viresh Kumar Content-Type: text/plain; charset=UTF-8 Sender: owner-linux-mm@kvack.org List-ID: To: Peter Zijlstra Cc: Christoph Lameter , Andrew Morton , Johannes Weiner , Linaro Kernel Mailman List , Linux Kernel Mailing List , vinmenon@codeaurora.org, shashim@codeaurora.org, Michal Hocko , Mel Gorman , dave@stgolabs.net, Konstantin Khlebnikov , Linux Memory Management List , Suresh Siddha , Thomas Gleixner On 27 March 2015 at 17:32, Peter Zijlstra wrote: > What's not clear to me is why that thing is allocated at all, AFAICT > something like: > > static DEFINE_PER_CPU(struct tvec_base, tvec_bases); > > Should do the right thing and be much simpler. Does this comment from timers.c answers your query ? /* * This is for the boot CPU - we use compile-time * static initialisation because per-cpu memory isn't * ready yet and because the memory allocators are not * initialised either. */ -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org