From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail3.caviumnetworks.com (mail3.caviumnetworks.com [12.108.191.235]) by ozlabs.org (Postfix) with ESMTP id D0449B7106 for ; Tue, 18 Jan 2011 06:19:17 +1100 (EST) Message-ID: <4D349621.1040603@caviumnetworks.com> Date: Mon, 17 Jan 2011 11:18:57 -0800 From: David Daney MIME-Version: 1.0 To: Peter Zijlstra Subject: Re: [PATCH] sched: provide scheduler_ipi() callback in response to smp_send_reschedule() References: <1295262433.30950.53.camel@laptop> In-Reply-To: <1295262433.30950.53.camel@laptop> Content-Type: text/plain; charset=UTF-8; format=flowed Cc: linux-m32r-ja@ml.linux-m32r.org, linux-mips@linux-mips.org, linux-ia64@vger.kernel.org, linux-sh@vger.kernel.org, Heiko Carstens , Paul Mackerras , "H. Peter Anvin" , sparclinux@vger.kernel.org, Linux-Arch , linux-s390@vger.kernel.org, Jesper Nilsson , Jeremy Fitzhardinge , Russell King , Hirokazu Takata , x86@kernel.org, "James E.J. Bottomley" , virtualization@lists.osdl.org, Ingo Molnar , Matt Turner , Fenghua Yu , Mike Frysinger , user-mode-linux-devel@lists.sourceforge.net, Konrad Rzeszutek Wilk , Jeff Dike , Chris Metcalf , xen-devel@lists.xensource.com, Mikael Starvik , linux-m32r@ml.linux-m32r.org, Ivan Kokshaysky , user-mode-linux-user@lists.sourceforge.net, uclinux-dist-devel@blackfin.uclinux.org, Thomas Gleixner , linux-arm-kernel@lists.infradead.org, Richard Henderson , Tony Luck , linux-parisc@vger.kernel.org, linux-cris-kernel@axis.com, linux-am33-list@redhat.com, linux-kernel@vger.kernel.org, Ralf Baechle , "David S. Miller" , Kyle McMartin , Paul Mundt , linux-alpha@vger.kernel.org, Martin Schwidefsky , linux390@de.ibm.com, Koichi Yasutake , linuxppc-dev@lists.ozlabs.org, Helge Deller List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On 01/17/2011 03:07 AM, Peter Zijlstra wrote: > For future rework of try_to_wake_up() we'd like to push part of that > onto the CPU the task is actually going to run on, in order to do so we > need a generic callback from the existing scheduler IPI. > > This patch introduces such a generic callback: scheduler_ipi() and > implements it as a NOP. > > I visited existing smp_send_reschedule() implementations and tried to > add a call to scheduler_ipi() in their handler part, but esp. for MIPS > I'm not quite sure I actually got all of them. > > Also, while reading through all this, I noticed the blackfin SMP code > looks to be broken, it simply discards any IPI when low on memory. > > Signed-off-by: Peter Zijlstra > --- > arch/alpha/kernel/smp.c | 1 + > arch/arm/kernel/smp.c | 1 + > arch/blackfin/mach-common/smp.c | 3 ++- > arch/cris/arch-v32/kernel/smp.c | 13 ++++++++----- > arch/ia64/kernel/irq_ia64.c | 2 ++ > arch/ia64/xen/irq_xen.c | 10 +++++++++- > arch/m32r/kernel/smp.c | 2 +- > arch/mips/kernel/smtc.c | 1 + > arch/mips/sibyte/bcm1480/smp.c | 7 +++---- > arch/mips/sibyte/sb1250/smp.c | 7 +++---- [...] Peter, You will also have to patch the mailbox_interrupt() function in arch/mips/cavium-octeon/smp.c David Daney.