Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756192AbbKRP54 (ORCPT ); Wed, 18 Nov 2015 10:57:56 -0500 Received: from mail-oi0-f53.google.com ([209.85.218.53]:36265 "EHLO mail-oi0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755191AbbKRP5z (ORCPT ); Wed, 18 Nov 2015 10:57:55 -0500 MIME-Version: 1.0 In-Reply-To: <20151118144811.GA1043@nuc-i3427.alporthouse.com> References: <20141008090336.GD12897@nuc-i3427.alporthouse.com> <20141008051059.65566251@as> <20151118144811.GA1043@nuc-i3427.alporthouse.com> From: Andy Lutomirski Date: Wed, 18 Nov 2015 07:57:35 -0800 Message-ID: Subject: Re: i915.ko WC writes are slow after ea8596bb2d8d379 To: Chris Wilson Cc: Chuck Ebbert , "linux-kernel@vger.kernel.org" , Andrew Morton , Tejun Heo , Rusty Russell , Peter Zijlstra , Masami Hiramatsu , Jiri Kosina , "H. Peter Anvin" , Steven Rostedt , Jason Baron , yrl.pp-manager.tt@hitachi.com, Borislav Petkov , Ingo Molnar , Daniel Vetter Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 989 Lines: 26 On Wed, Nov 18, 2015 at 6:48 AM, Chris Wilson wrote: > Although > > diff --git a/include/linux/stop_machine.h b/include/linux/stop_machine.h > index d2abbdb..ff4f029 100644 > --- a/include/linux/stop_machine.h > +++ b/include/linux/stop_machine.h > @@ -97,7 +97,7 @@ static inline int try_stop_cpus(const struct cpumask *cpumask, > * grabbing every spinlock (and more). So the "read" side to such a > * lock is anything which disables preemption. > */ > -#if defined(CONFIG_STOP_MACHINE) && defined(CONFIG_SMP) > +#if defined(CONFIG_SMP) || defined(CONFIG_HOTPLUG_CPU) [...] This seems much better. Having a set of stop_machine functions around that don't work depending on config seems dangerous. --Andy -- 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/