From mboxrd@z Thu Jan 1 00:00:00 1970 From: Oleg Nesterov Date: Mon, 26 Mar 2012 17:04:43 +0000 Subject: Re: [PATCH v2.1 01/10] cpu: Introduce clear_tasks_mm_cpumask() helper Message-Id: <20120326170443.GA25229@redhat.com> List-Id: References: <20120324102609.GA28356@lizard> <20120324102751.GA29067@lizard> <1332593021.16159.27.camel@twins> <20120324164316.GB3640@lizard> <20120325174210.GA23605@redhat.com> <1332748746.16159.62.camel@twins> In-Reply-To: <1332748746.16159.62.camel@twins> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-arm-kernel@lists.infradead.org On 03/26, Peter Zijlstra wrote: > > On Sun, 2012-03-25 at 19:42 +0200, Oleg Nesterov wrote: > > __cpu_disable() is called by __stop_machine(), we know that nobody > > can preempt us and other CPUs can do nothing. > > It would be very good to not rely on that though, Yes, yes, perhaps I wasn't clear but I think the patches are fine. > I would love to get > rid of the stop_machine usage in cpu hotplug some day. Interesting... Why? I mean, why do you dislike stop_machine() in _cpu_down() ? Just curious. Oleg. From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Mon, 26 Mar 2012 19:04:43 +0200 From: Oleg Nesterov Message-ID: <20120326170443.GA25229@redhat.com> References: <20120324102609.GA28356@lizard> <20120324102751.GA29067@lizard> <1332593021.16159.27.camel@twins> <20120324164316.GB3640@lizard> <20120325174210.GA23605@redhat.com> <1332748746.16159.62.camel@twins> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1332748746.16159.62.camel@twins> Sender: linux-kernel-owner@vger.kernel.org Subject: Re: [PATCH v2.1 01/10] cpu: Introduce clear_tasks_mm_cpumask() helper To: Peter Zijlstra Cc: Anton Vorontsov , Andrew Morton , Russell King , Mike Frysinger , Benjamin Herrenschmidt , Richard Weinberger , Paul Mundt , KOSAKI Motohiro , John Stultz , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, uclinux-dist-devel@blackfin.uclinux.org, linuxppc-dev@lists.ozlabs.org, linux-sh@vger.kernel.org, user-mode-linux-devel@lists.sourceforge.net, linux-mm@kvack.org List-ID: On 03/26, Peter Zijlstra wrote: > > On Sun, 2012-03-25 at 19:42 +0200, Oleg Nesterov wrote: > > __cpu_disable() is called by __stop_machine(), we know that nobody > > can preempt us and other CPUs can do nothing. > > It would be very good to not rely on that though, Yes, yes, perhaps I wasn't clear but I think the patches are fine. > I would love to get > rid of the stop_machine usage in cpu hotplug some day. Interesting... Why? I mean, why do you dislike stop_machine() in _cpu_down() ? Just curious. Oleg. From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) by ozlabs.org (Postfix) with ESMTP id 98043B6EEC for ; Tue, 27 Mar 2012 04:13:26 +1100 (EST) Date: Mon, 26 Mar 2012 19:04:43 +0200 From: Oleg Nesterov To: Peter Zijlstra Subject: Re: [PATCH v2.1 01/10] cpu: Introduce clear_tasks_mm_cpumask() helper Message-ID: <20120326170443.GA25229@redhat.com> References: <20120324102609.GA28356@lizard> <20120324102751.GA29067@lizard> <1332593021.16159.27.camel@twins> <20120324164316.GB3640@lizard> <20120325174210.GA23605@redhat.com> <1332748746.16159.62.camel@twins> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <1332748746.16159.62.camel@twins> Cc: Mike Frysinger , user-mode-linux-devel@lists.sourceforge.net, linux-sh@vger.kernel.org, Richard Weinberger , linux-kernel@vger.kernel.org, uclinux-dist-devel@blackfin.uclinux.org, linux-mm@kvack.org, Anton Vorontsov , Paul Mundt , John Stultz , KOSAKI Motohiro , Russell King , Andrew Morton , linuxppc-dev@lists.ozlabs.org, linux-arm-kernel@lists.infradead.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On 03/26, Peter Zijlstra wrote: > > On Sun, 2012-03-25 at 19:42 +0200, Oleg Nesterov wrote: > > __cpu_disable() is called by __stop_machine(), we know that nobody > > can preempt us and other CPUs can do nothing. > > It would be very good to not rely on that though, Yes, yes, perhaps I wasn't clear but I think the patches are fine. > I would love to get > rid of the stop_machine usage in cpu hotplug some day. Interesting... Why? I mean, why do you dislike stop_machine() in _cpu_down() ? Just curious. Oleg. From mboxrd@z Thu Jan 1 00:00:00 1970 From: oleg@redhat.com (Oleg Nesterov) Date: Mon, 26 Mar 2012 19:04:43 +0200 Subject: [PATCH v2.1 01/10] cpu: Introduce clear_tasks_mm_cpumask() helper In-Reply-To: <1332748746.16159.62.camel@twins> References: <20120324102609.GA28356@lizard> <20120324102751.GA29067@lizard> <1332593021.16159.27.camel@twins> <20120324164316.GB3640@lizard> <20120325174210.GA23605@redhat.com> <1332748746.16159.62.camel@twins> Message-ID: <20120326170443.GA25229@redhat.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 03/26, Peter Zijlstra wrote: > > On Sun, 2012-03-25 at 19:42 +0200, Oleg Nesterov wrote: > > __cpu_disable() is called by __stop_machine(), we know that nobody > > can preempt us and other CPUs can do nothing. > > It would be very good to not rely on that though, Yes, yes, perhaps I wasn't clear but I think the patches are fine. > I would love to get > rid of the stop_machine usage in cpu hotplug some day. Interesting... Why? I mean, why do you dislike stop_machine() in _cpu_down() ? Just curious. Oleg. From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx183.postini.com [74.125.245.183]) by kanga.kvack.org (Postfix) with SMTP id 07A046B0044 for ; Mon, 26 Mar 2012 13:13:14 -0400 (EDT) Date: Mon, 26 Mar 2012 19:04:43 +0200 From: Oleg Nesterov Subject: Re: [PATCH v2.1 01/10] cpu: Introduce clear_tasks_mm_cpumask() helper Message-ID: <20120326170443.GA25229@redhat.com> References: <20120324102609.GA28356@lizard> <20120324102751.GA29067@lizard> <1332593021.16159.27.camel@twins> <20120324164316.GB3640@lizard> <20120325174210.GA23605@redhat.com> <1332748746.16159.62.camel@twins> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1332748746.16159.62.camel@twins> Sender: owner-linux-mm@kvack.org List-ID: To: Peter Zijlstra Cc: Anton Vorontsov , Andrew Morton , Russell King , Mike Frysinger , Benjamin Herrenschmidt , Richard Weinberger , Paul Mundt , KOSAKI Motohiro , John Stultz , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, uclinux-dist-devel@blackfin.uclinux.org, linuxppc-dev@lists.ozlabs.org, linux-sh@vger.kernel.org, user-mode-linux-devel@lists.sourceforge.net, linux-mm@kvack.org On 03/26, Peter Zijlstra wrote: > > On Sun, 2012-03-25 at 19:42 +0200, Oleg Nesterov wrote: > > __cpu_disable() is called by __stop_machine(), we know that nobody > > can preempt us and other CPUs can do nothing. > > It would be very good to not rely on that though, Yes, yes, perhaps I wasn't clear but I think the patches are fine. > I would love to get > rid of the stop_machine usage in cpu hotplug some day. Interesting... Why? I mean, why do you dislike stop_machine() in _cpu_down() ? Just curious. Oleg. -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org