From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gate.crashing.org (gate.crashing.org [63.228.1.57]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id B043DB6EF2 for ; Thu, 12 Jan 2012 10:06:41 +1100 (EST) Message-ID: <1326323168.23910.168.camel@pasglop> Subject: Re: cpuidle: Default y for pseries From: Benjamin Herrenschmidt To: Thadeu Lima de Souza Cascardo Date: Thu, 12 Jan 2012 10:06:08 +1100 In-Reply-To: <20120111223744.GA30947@oc1711230544.ibm.com> References: <1326243935.23910.85.camel@pasglop> <20120111223744.GA30947@oc1711230544.ibm.com> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Cc: Venkatesh Pallipadi , linuxppc-dev@ozlabs.org, linux-pm@vger.kernel.org, Linus Torvalds , Shaohua Li List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Wed, 2012-01-11 at 20:37 -0200, Thadeu Lima de Souza Cascardo wrote: > On Tue, Jan 10, 2012 at 03:05:35PM -0000, Benjamin Herrenschmidt wrote: > > We just replaced the pseries platform idle loops with a cpuidle backend, > > however that means that you won't get any power saving and won't return > > any unused idle time to the hypervisor unless cpuidle is enabled. > > > > Thus is should default to y when pseries is enabled. I prefer that to > > a select so we can still make it modular if we want to. > > > > Signed-off-by: Benjamin Herrenschmidt > > > > --- > > Linus, do you want to just pick that up or should I put it into powerpc.git > > and ask you to pull ? I will have 2 or 3 other fixes there later today, > > but I wanted to make sure you were ok with the approach with this > > specific one. > > Hi, Ben. > > Note that building with CONFIG_PSERIES_IDLE=m fails. Ah ok. Well, making it built-in only makes sense anyway as I said separately, so I think I'll just select it. Cheers, Ben. > CC [M] arch/powerpc/platforms/pseries/processor_idle.o > arch/powerpc/platforms/pseries/processor_idle.c:35: error: redefinition > of ‘update_smt_snooze_delay’ > /root/linux/arch/powerpc/include/asm/system.h:230: note: previous > definition of ‘update_smt_snooze_delay’ was here > arch/powerpc/platforms/pseries/processor_idle.c:175: error: redefinition > of ‘pseries_notify_cpuidle_add_cpu’ > /root/linux/arch/powerpc/include/asm/system.h:231: note: previous > definition of ‘pseries_notify_cpuidle_add_cpu’ was here > make[2]: *** [arch/powerpc/platforms/pseries/processor_idle.o] Error 1 > make[1]: *** [arch/powerpc/platforms/pseries] Error 2 > make: *** [arch/powerpc/platforms] Error 2 > > asm/system.h has empty inline implementations for > update_smt_snooze_delay and pseries_notify_cpuidle_add_cpu, which are > used when CONFIG_PSERIES_IDLE is undefined. Since those two functions > are used in core power architecture functions (store_smt_snooze_delay > at kernel/sysfs.c and smp_xics_setup_cpu at platforms/pseries/smp.c), > this requires some rework in these interactions or we should simply > disable PSERIES_IDLE to be built as a module for now. > > Regards. > Cascardo. > > > > > diff --git a/drivers/cpuidle/Kconfig b/drivers/cpuidle/Kconfig > > index 7dbc4a8..62ca70d 100644 > > --- a/drivers/cpuidle/Kconfig > > +++ b/drivers/cpuidle/Kconfig > > @@ -1,7 +1,8 @@ > > > > config CPU_IDLE > > bool "CPU idle PM support" > > - default ACPI > > + default y if ACPI > > + default y if PPC_PSERIES > > help > > CPU idle is a generic framework for supporting software-controlled > > idle processor power management. It includes modular cross-platform