Hi, Jacob, On Fri, 2013-01-04 at 03:12 -0800, Jacob Pan wrote: > Intel PowerClamp driver performs synchronized idle injection across > all online CPUs. The goal is to maintain a given package level C-state > ratio. > > Compared to other throttling methods already exist in the kernel, > such as ACPI PAD (taking CPUs offline) and clock modulation, this is often > more efficient in terms of performance per watt. > > Please refer to Documentation/thermal/intel_powerclamp.txt for more details. > > Signed-off-by: Arjan van de Ven <ar...@linux.intel.com> > Signed-off-by: Jacob Pan <jacob.jun....@linux.intel.com> > --- > Documentation/thermal/intel_powerclamp.txt | 307 +++++++++++ > drivers/thermal/Kconfig | 10 + > drivers/thermal/Makefile | 2 + > drivers/thermal/intel_powerclamp.c | 788 > ++++++++++++++++++++++++++++ > 4 files changed, 1107 insertions(+) > create mode 100644 Documentation/thermal/intel_powerclamp.txt > create mode 100644 drivers/thermal/intel_powerclamp.c
> diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig > index c2c77d1..7d90ab8 100644 > --- a/drivers/thermal/Kconfig > +++ b/drivers/thermal/Kconfig > @@ -122,4 +122,14 @@ config DB8500_CPUFREQ_COOLING > bound cpufreq cooling device turns active to set CPU frequency low to > cool down the CPU. > > +config INTEL_POWERCLAMP > + tristate "Intel PowerClamp idle injection driver" > + depends on THERMAL > + depends on X86 > + depends on CPU_SUP_INTEL > + help > + Enable this to enable Intel PowerClamp idle injection driver. This > + enforce idle time which results in more package C-state residency. The > + user interface is exposed via generic thermal framework. > + > endif > diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile > index d8da683..574f5f5 100644 > --- a/drivers/thermal/Makefile > +++ b/drivers/thermal/Makefile > @@ -18,3 +18,5 @@ obj-$(CONFIG_RCAR_THERMAL) += rcar_thermal.o > obj-$(CONFIG_EXYNOS_THERMAL) += exynos_thermal.o > obj-$(CONFIG_DB8500_THERMAL) += db8500_thermal.o > obj-$(CONFIG_DB8500_CPUFREQ_COOLING) += db8500_cpufreq_cooling.o > +obj-$(CONFIG_INTEL_POWERCLAMP) += intel_powerclamp.o > + > diff --git a/drivers/thermal/intel_powerclamp.c > b/drivers/thermal/intel_powerclamp.c > new file mode 100644 > index 0000000..314b6fc > --- /dev/null > +++ b/drivers/thermal/intel_powerclamp.c > @@ -0,0 +1,788 @@ > +/* > + * intel_powerclamp.c - package c-state idle injection > + * > + * Copyright (c) 2012, Intel Corporation. > + * > + * Authors: > + * Arjan van de Ven <ar...@linux.intel.com> > + * Jacob Pan <jacob.jun....@linux.intel.com> > + * > + * This program is free software; you can redistribute it and/or modify it > + * under the terms and conditions of the GNU General Public License, > + * version 2, as published by the Free Software Foundation. > + * > + * This program is distributed in the hope it will be useful, but WITHOUT > + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or > + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for > + * more details. > + * > + * You should have received a copy of the GNU General Public License along > with > + * this program; if not, write to the Free Software Foundation, Inc., > + * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA. > + * > + * > + * TODO: > + * 1. better handle wakeup from external interrupts, currently a > fixed > + * compensation is added to clamping duration when excessive > amount > + * of wakeups are observed during idle time. the reason is that > in > + * case of external interrupts without need for ack, clamping > down > + * cpu in non-irq context does not reduce irq. for majority of > the > + * cases, clamping down cpu does help reduce irq as well, we > should > + * be able to differenciate the two cases and give a > quantitative > + * solution for the irqs that we can control. perhaps based on > + * get_cpu_iowait_time_us() > + * > + * 2. synchronization with other hw blocks > + * > + * > + */ > + > +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt > + > +#include <linux/module.h> > +#include <linux/kernel.h> > +#include <linux/delay.h> > +#include <linux/kthread.h> > +#include <linux/freezer.h> > +#include <linux/cpu.h> > +#include <linux/thermal.h> > +#include <linux/slab.h> > +#include <linux/tick.h> > +#include <linux/debugfs.h> > +#include <linux/seq_file.h> > +#include <linux/nmi.h> > + drivers/thermal/intel_powerclamp.c: In function ‘clamp_thread’: drivers/thermal/intel_powerclamp.c:435:4: error: implicit declaration of function ‘local_touch_nmi’ [-Werror=implicit-function-declaration] changing to #include <asm/nmi.h> fixes the problem. thanks, rui -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
