Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754066AbYLGH1t (ORCPT ); Sun, 7 Dec 2008 02:27:49 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752554AbYLGH1j (ORCPT ); Sun, 7 Dec 2008 02:27:39 -0500 Received: from smtp1.linux-foundation.org ([140.211.169.13]:50730 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752506AbYLGH1i (ORCPT ); Sun, 7 Dec 2008 02:27:38 -0500 Date: Sat, 6 Dec 2008 23:27:14 -0800 From: Andrew Morton To: Ken Chen Cc: Ingo Molnar , Li Zefan , Paul Menage , Linux Kernel Mailing List Subject: Re: [patch] export percpu cpuacct cgroup stats Message-Id: <20081206232714.4b34b2fc.akpm@linux-foundation.org> In-Reply-To: References: <49376BE3.1040909@cn.fujitsu.com> <6599ad830812041502m15f54f0ckd8baa0a1792fc31e@mail.gmail.com> <4938DE1C.6070608@cn.fujitsu.com> <4938E7C1.9040102@cn.fujitsu.com> <20081205135253.GE27039@elte.hu> X-Mailer: Sylpheed 2.4.8 (GTK+ 2.12.5; x86_64-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1000 Lines: 30 On Fri, 5 Dec 2008 10:16:30 -0800 Ken Chen wrote: > +static int cpuacct_percpu_seq_read(struct cgroup *cgroup, struct cftype *cft, > + struct seq_file *m) > +{ > + struct cpuacct *ca = cgroup_ca(cgroup); > + u64 percpu; > + int i; > + > + for_each_possible_cpu(i) { > + spin_lock_irq(&cpu_rq(i)->lock); > + percpu = *percpu_ptr(ca->cpuusage, i); > + spin_unlock_irq(&cpu_rq(i)->lock); > + seq_printf(m, "%llu ", (unsigned long long) percpu); > + } > + seq_printf(m, "\n"); > + return 0; > +} The locking is only needed for 32-bit, I assume? The iteration across all possible CPUs seems a bit lame - that code looks pretty easy to convert to hotplug goodness. (All of which pertains to existing code, not to this patch). -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/