From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e28smtp09.in.ibm.com (e28smtp09.in.ibm.com [122.248.162.9]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "e28smtp09.in.ibm.com", Issuer "GeoTrust SSL CA" (not verified)) by ozlabs.org (Postfix) with ESMTPS id A0A972C0108 for ; Fri, 26 Jul 2013 15:17:48 +1000 (EST) Received: from /spool/local by e28smtp09.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Fri, 26 Jul 2013 10:42:12 +0530 Received: from d28relay02.in.ibm.com (d28relay02.in.ibm.com [9.184.220.59]) by d28dlp02.in.ibm.com (Postfix) with ESMTP id 7CD71394005B for ; Fri, 26 Jul 2013 10:47:03 +0530 (IST) Received: from d28av02.in.ibm.com (d28av02.in.ibm.com [9.184.220.64]) by d28relay02.in.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id r6Q5I7m540239184 for ; Fri, 26 Jul 2013 10:48:07 +0530 Received: from d28av02.in.ibm.com (loopback [127.0.0.1]) by d28av02.in.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id r6Q5H5wj003144 for ; Fri, 26 Jul 2013 15:17:08 +1000 Subject: [Resend RFC PATCH 0/5] cpuidle/ppc: Timer offload framework to support deep idle states To: benh@kernel.crashing.org, paul.gortmaker@windriver.com, paulus@samba.org, shangw@linux.vnet.ibm.com, galak@kernel.crashing.org, fweisbec@gmail.com, paulmck@linux.vnet.ibm.com, michael@ellerman.id.au, arnd@arndb.de, linux-pm@vger.kernel.org, rostedt@goodmis.org, rjw@sisk.pl, john.stultz@linaro.org, tglx@linutronix.de, chenhui.zhao@freescale.com, deepthi@linux.vnet.ibm.com, geoff@infradead.org, linux-kernel@vger.kernel.org, srivatsa.bhat@linux.vnet.ibm.com, schwidefsky@de.ibm.com, svaidy@linux.vnet.ibm.com, linuxppc-dev@lists.ozlabs.org From: Preeti U Murthy Date: Fri, 26 Jul 2013 10:43:54 +0530 Message-ID: <20130726050915.17167.16298.stgit@preeti> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On PowerPC, when CPUs enter deep idle states, their local timers are switched off. The responsibility of waking them up at their next timer event, needs to be handed over to an external device. On PowerPC, we do not have an external device equivalent to HPET, which is currently done on architectures like x86. Instead we assign the local timer of one of the CPUs to do this job. This patchset is an attempt to make use of the existing timer broadcast framework in the kernel to meet the above requirement, except that the tick broadcast device is the local timer of the boot CPU. This patch series is ported ontop of 3.11-rc1 + the cpuidle driver backend for powernv posted by Deepthi Dharwar recently. The current design and implementation supports the ONESHOT tick mode. It does not yet support the PERIODIC tick mode. This patch is tested with NOHZ_FULL off. Patch[1/5], Patch[2/5]: optimize the broadcast mechanism on ppc. Patch[3/5]: Introduces the core of the timer offload framework on powerpc. Patch[4/5]: The cpu doing the broadcast should not go into tickless idle. Patch[5/5]: Add a deep idle state to the cpuidle state table on powernv. Patch[5/5] is the patch that ultimately makes use of the timer offload framework that the patches Patch[1/5] to Patch[4/5] build. This patch series is being resent to clarify certain ambiguity in the patch descriptions from the previous post. Discussion around this: https://lkml.org/lkml/2013/7/25/754 --- Preeti U Murthy (3): cpuidle/ppc: Add timer offload framework to support deep idle states cpuidle/ppc: CPU goes tickless if there are no arch-specific constraints cpuidle/ppc: Add longnap state to the idle states on powernv Srivatsa S. Bhat (2): powerpc: Free up the IPI message slot of ipi call function (PPC_MSG_CALL_FUNC) powerpc: Implement broadcast timer interrupt as an IPI message arch/powerpc/include/asm/smp.h | 3 + arch/powerpc/include/asm/time.h | 3 + arch/powerpc/kernel/smp.c | 23 ++++-- arch/powerpc/kernel/time.c | 86 +++++++++++++++++++++++ arch/powerpc/platforms/cell/interrupt.c | 2 - arch/powerpc/platforms/powernv/Kconfig | 1 arch/powerpc/platforms/powernv/processor_idle.c | 48 +++++++++++++ arch/powerpc/platforms/ps3/smp.c | 2 - kernel/time/tick-sched.c | 7 ++ 9 files changed, 163 insertions(+), 12 deletions(-)