linux_old1/include/linux/tick.h

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/*
* Tick related global functions
*/
#ifndef _LINUX_TICK_H
#define _LINUX_TICK_H
#include <linux/clockchips.h>
nohz: Allow rcu extended quiescent state handling seperately from tick stop It is assumed that rcu won't be used once we switch to tickless mode and until we restart the tick. However this is not always true, as in x86-64 where we dereference the idle notifiers after the tick is stopped. To prepare for fixing this, add two new APIs: tick_nohz_idle_enter_norcu() and tick_nohz_idle_exit_norcu(). If no use of RCU is made in the idle loop between tick_nohz_enter_idle() and tick_nohz_exit_idle() calls, the arch must instead call the new *_norcu() version such that the arch doesn't need to call rcu_idle_enter() and rcu_idle_exit(). Otherwise the arch must call tick_nohz_enter_idle() and tick_nohz_exit_idle() and also call explicitly: - rcu_idle_enter() after its last use of RCU before the CPU is put to sleep. - rcu_idle_exit() before the first use of RCU after the CPU is woken up. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Mike Frysinger <vapier@gentoo.org> Cc: Guan Xuetao <gxt@mprc.pku.edu.cn> Cc: David Miller <davem@davemloft.net> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Hans-Christian Egtvedt <hans-christian.egtvedt@atmel.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Paul Mackerras <paulus@samba.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Paul Mundt <lethal@linux-sh.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2011-10-08 22:01:00 +08:00
#include <linux/irqflags.h>
#include <linux/percpu.h>
#include <linux/context_tracking_state.h>
#include <linux/cpumask.h>
#include <linux/sched.h>
#ifdef CONFIG_GENERIC_CLOCKEVENTS
extern void __init tick_init(void);
/* Should be core only, but ARM BL switcher requires it */
extern void tick_suspend_local(void);
/* Should be core only, but XEN resume magic and ARM BL switcher require it */
extern void tick_resume_local(void);
extern void tick_handover_do_timer(void);
extern void tick_cleanup_dead_cpu(int cpu);
#else /* CONFIG_GENERIC_CLOCKEVENTS */
static inline void tick_init(void) { }
static inline void tick_suspend_local(void) { }
static inline void tick_resume_local(void) { }
static inline void tick_handover_do_timer(void) { }
static inline void tick_cleanup_dead_cpu(int cpu) { }
#endif /* !CONFIG_GENERIC_CLOCKEVENTS */
PM / sleep: Make it possible to quiesce timers during suspend-to-idle The efficiency of suspend-to-idle depends on being able to keep CPUs in the deepest available idle states for as much time as possible. Ideally, they should only be brought out of idle by system wakeup interrupts. However, timer interrupts occurring periodically prevent that from happening and it is not practical to chase all of the "misbehaving" timers in a whack-a-mole fashion. A much more effective approach is to suspend the local ticks for all CPUs and the entire timekeeping along the lines of what is done during full suspend, which also helps to keep suspend-to-idle and full suspend reasonably similar. The idea is to suspend the local tick on each CPU executing cpuidle_enter_freeze() and to make the last of them suspend the entire timekeeping. That should prevent timer interrupts from triggering until an IO interrupt wakes up one of the CPUs. It needs to be done with interrupts disabled on all of the CPUs, though, because otherwise the suspended clocksource might be accessed by an interrupt handler which might lead to fatal consequences. Unfortunately, the existing ->enter callbacks provided by cpuidle drivers generally cannot be used for implementing that, because some of them re-enable interrupts temporarily and some idle entry methods cause interrupts to be re-enabled automatically on exit. Also some of these callbacks manipulate local clock event devices of the CPUs which really shouldn't be done after suspending their ticks. To overcome that difficulty, introduce a new cpuidle state callback, ->enter_freeze, that will be guaranteed (1) to keep interrupts disabled all the time (and return with interrupts disabled) and (2) not to touch the CPU timer devices. Modify cpuidle_enter_freeze() to look for the deepest available idle state with ->enter_freeze present and to make the CPU execute that callback with suspended tick (and the last of the online CPUs to execute it with suspended timekeeping). Suggested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2015-02-14 06:50:43 +08:00
#if defined(CONFIG_GENERIC_CLOCKEVENTS) && defined(CONFIG_SUSPEND)
extern void tick_freeze(void);
extern void tick_unfreeze(void);
#else
static inline void tick_freeze(void) { }
static inline void tick_unfreeze(void) { }
#endif
#ifdef CONFIG_TICK_ONESHOT
extern void tick_irq_enter(void);
# ifndef arch_needs_cpu
# define arch_needs_cpu() (0)
# endif
# else
static inline void tick_irq_enter(void) { }
#endif
clockevents: Fix cpu_down() race for hrtimer based broadcasting It was found when doing a hotplug stress test on POWER, that the machine either hit softlockups or rcu_sched stall warnings. The issue was traced to commit: 7cba160ad789 ("powernv/cpuidle: Redesign idle states management") which exposed the cpu_down() race with hrtimer based broadcast mode: 5d1638acb9f6 ("tick: Introduce hrtimer based broadcast") The race is the following: Assume CPU1 is the CPU which holds the hrtimer broadcasting duty before it is taken down. CPU0 CPU1 cpu_down() take_cpu_down() disable_interrupts() cpu_die() while (CPU1 != CPU_DEAD) { msleep(100); switch_to_idle(); stop_cpu_timer(); schedule_broadcast(); } tick_cleanup_cpu_dead() take_over_broadcast() So after CPU1 disabled interrupts it cannot handle the broadcast hrtimer anymore, so CPU0 will be stuck forever. Fix this by explicitly taking over broadcast duty before cpu_die(). This is a temporary workaround. What we really want is a callback in the clockevent device which allows us to do that from the dying CPU by pushing the hrtimer onto a different cpu. That might involve an IPI and is definitely more complex than this immediate fix. Changelog was picked up from: https://lkml.org/lkml/2015/2/16/213 Suggested-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Preeti U. Murthy <preeti@linux.vnet.ibm.com> Cc: linuxppc-dev@lists.ozlabs.org Cc: mpe@ellerman.id.au Cc: nicolas.pitre@linaro.org Cc: peterz@infradead.org Cc: rjw@rjwysocki.net Fixes: http://linuxppc.10917.n7.nabble.com/offlining-cpus-breakage-td88619.html Link: http://lkml.kernel.org/r/20150330092410.24979.59887.stgit@preeti.in.ibm.com [ Merged it to the latest timer tree, renamed the callback, tidied up the changelog. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-30 17:29:19 +08:00
#if defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST) && defined(CONFIG_TICK_ONESHOT)
extern void hotplug_cpu__broadcast_tick_pull(int dead_cpu);
#else
static inline void hotplug_cpu__broadcast_tick_pull(int dead_cpu) { }
#endif
enum tick_broadcast_mode {
TICK_BROADCAST_OFF,
TICK_BROADCAST_ON,
TICK_BROADCAST_FORCE,
};
enum tick_broadcast_state {
TICK_BROADCAST_EXIT,
TICK_BROADCAST_ENTER,
};
#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
extern void tick_broadcast_control(enum tick_broadcast_mode mode);
#else
static inline void tick_broadcast_control(enum tick_broadcast_mode mode) { }
#endif /* BROADCAST */
extern int tick_broadcast_oneshot_control(enum tick_broadcast_state state);
static inline void tick_broadcast_enable(void)
{
tick_broadcast_control(TICK_BROADCAST_ON);
}
static inline void tick_broadcast_disable(void)
{
tick_broadcast_control(TICK_BROADCAST_OFF);
}
static inline void tick_broadcast_force(void)
{
tick_broadcast_control(TICK_BROADCAST_FORCE);
}
static inline int tick_broadcast_enter(void)
{
return tick_broadcast_oneshot_control(TICK_BROADCAST_ENTER);
}
static inline void tick_broadcast_exit(void)
{
tick_broadcast_oneshot_control(TICK_BROADCAST_EXIT);
}
#ifdef CONFIG_NO_HZ_COMMON
extern int tick_nohz_tick_stopped(void);
extern void tick_nohz_idle_enter(void);
nohz: Separate out irq exit and idle loop dyntick logic The tick_nohz_stop_sched_tick() function, which tries to delay the next timer tick as long as possible, can be called from two places: - From the idle loop to start the dytick idle mode - From interrupt exit if we have interrupted the dyntick idle mode, so that we reprogram the next tick event in case the irq changed some internal state that requires this action. There are only few minor differences between both that are handled by that function, driven by the ts->inidle cpu variable and the inidle parameter. The whole guarantees that we only update the dyntick mode on irq exit if we actually interrupted the dyntick idle mode, and that we enter in RCU extended quiescent state from idle loop entry only. Split this function into: - tick_nohz_idle_enter(), which sets ts->inidle to 1, enters dynticks idle mode unconditionally if it can, and enters into RCU extended quiescent state. - tick_nohz_irq_exit() which only updates the dynticks idle mode when ts->inidle is set (ie: if tick_nohz_idle_enter() has been called). To maintain symmetry, tick_nohz_restart_sched_tick() has been renamed into tick_nohz_idle_exit(). This simplifies the code and micro-optimize the irq exit path (no need for local_irq_save there). This also prepares for the split between dynticks and rcu extended quiescent state logics. We'll need this split to further fix illegal uses of RCU in extended quiescent states in the idle loop. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Mike Frysinger <vapier@gentoo.org> Cc: Guan Xuetao <gxt@mprc.pku.edu.cn> Cc: David Miller <davem@davemloft.net> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Hans-Christian Egtvedt <hans-christian.egtvedt@atmel.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Paul Mackerras <paulus@samba.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Paul Mundt <lethal@linux-sh.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2011-10-08 00:22:06 +08:00
extern void tick_nohz_idle_exit(void);
extern void tick_nohz_irq_exit(void);
cpuidle: consolidate 2.6.22 cpuidle branch into one patch commit e5a16b1f9eec0af7cfa0830304b41c1c0833cf9f Author: Len Brown <len.brown@intel.com> Date: Tue Oct 2 23:44:44 2007 -0400 cpuidle: shrink diff processor_idle.c | 440 +++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 429 insertions(+), 11 deletions(-) Signed-off-by: Len Brown <len.brown@intel.com> commit dfbb9d5aedfb18848a3e0d6f6e3e4969febb209c Author: Len Brown <len.brown@intel.com> Date: Wed Sep 26 02:17:55 2007 -0400 cpuidle: reduce diff size Reduces the cpuidle processor_idle.c diff vs 2.6.22 from this processor_idle.c | 2006 ++++++++++++++++++++++++++----------------- 1 file changed, 1219 insertions(+), 787 deletions(-) to this: processor_idle.c | 502 +++++++++++++++++++++++++++++++++++++++---- 1 file changed, 458 insertions(+), 44 deletions(-) ...for the purpose of making the cpuilde patch less invasive and easier to review. no functional changes. build tested only. Signed-off-by: Len Brown <len.brown@intel.com> commit 889172fc915f5a7fe20f35b133cbd205ce69bf6c Author: Venki Pallipadi <venkatesh.pallipadi@intel.com> Date: Thu Sep 13 13:40:05 2007 -0700 cpuidle: Retain old ACPI policy for !CONFIG_CPU_IDLE Retain the old policy in processor_idle, so that when CPU_IDLE is not configured, old C-state policy will still be used. This provides a clean gradual migration path from old ACPI policy to new cpuidle based policy. Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Len Brown <len.brown@intel.com> commit 9544a8181edc7ecc33b3bfd69271571f98ed08bc Author: Venki Pallipadi <venkatesh.pallipadi@intel.com> Date: Thu Sep 13 13:39:17 2007 -0700 cpuidle: Configure governors by default Quoting Len "Do not give an option to users to shoot themselves in the foot". Remove the configurability of ladder and menu governors as they are needed for default policy of cpuidle. That way users will not be able to have cpuidle without any policy loosing all C-state power savings. Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Len Brown <len.brown@intel.com> commit 8975059a2c1e56cfe83d1bcf031bcf4cb39be743 Author: Adam Belay <abelay@novell.com> Date: Tue Aug 21 18:27:07 2007 -0400 CPUIDLE: load ACPI properly when CPUIDLE is disabled Change the registration return codes for when CPUIDLE support is not compiled into the kernel. As a result, the ACPI processor driver will load properly even if CPUIDLE is unavailable. However, it may be possible to cleanup the ACPI processor driver further and eliminate some dead code paths. Signed-off-by: Adam Belay <abelay@novell.com> Acked-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Len Brown <len.brown@intel.com> commit e0322e2b58dd1b12ec669bf84693efe0dc2414a8 Author: Adam Belay <abelay@novell.com> Date: Tue Aug 21 18:26:06 2007 -0400 CPUIDLE: remove cpuidle_get_bm_activity() Remove cpuidle_get_bm_activity() and updates governors accordingly. Signed-off-by: Adam Belay <abelay@novell.com> Acked-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Len Brown <len.brown@intel.com> commit 18a6e770d5c82ba26653e53d240caa617e09e9ab Author: Adam Belay <abelay@novell.com> Date: Tue Aug 21 18:25:58 2007 -0400 CPUIDLE: max_cstate fix Currently max_cstate is limited to 0, resulting in no idle processor power management on ACPI platforms. This patch restores the value to the array size. Signed-off-by: Adam Belay <abelay@novell.com> Acked-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Len Brown <len.brown@intel.com> commit 1fdc0887286179b40ce24bcdbde663172e205ef0 Author: Adam Belay <abelay@novell.com> Date: Tue Aug 21 18:25:40 2007 -0400 CPUIDLE: handle BM detection inside the ACPI Processor driver Update the ACPI processor driver to detect BM activity and limit state entry depth internally, rather than exposing such requirements to CPUIDLE. As a result, CPUIDLE can drop this ACPI-specific interface and become more platform independent. BM activity is now handled much more aggressively than it was in the original implementation, so some testing coverage may be needed to verify that this doesn't introduce any DMA buffer under-run issues. Signed-off-by: Adam Belay <abelay@novell.com> Acked-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Len Brown <len.brown@intel.com> commit 0ef38840db666f48e3cdd2b769da676c57228dd9 Author: Adam Belay <abelay@novell.com> Date: Tue Aug 21 18:25:14 2007 -0400 CPUIDLE: menu governor updates Tweak the menu governor to more effectively handle non-timer break events. Non-timer break events are detected by comparing the actual sleep time to the expected sleep time. In future revisions, it may be more reliable to use the timer data structures directly. Signed-off-by: Adam Belay <abelay@novell.com> Acked-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Len Brown <len.brown@intel.com> commit bb4d74fca63fa96cf3ace644b15ae0f12b7df5a1 Author: Adam Belay <abelay@novell.com> Date: Tue Aug 21 18:24:40 2007 -0400 CPUIDLE: fix 'current_governor' sysfs entry Allow the "current_governor" sysfs entry to properly handle input terminated with '\n'. Signed-off-by: Adam Belay <abelay@novell.com> Acked-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Len Brown <len.brown@intel.com> commit df3c71559bb69b125f1a48971bf0d17f78bbdf47 Author: Len Brown <len.brown@intel.com> Date: Sun Aug 12 02:00:45 2007 -0400 cpuidle: fix IA64 build (again) Signed-off-by: Len Brown <len.brown@intel.com> commit a02064579e3f9530fd31baae16b1fc46b5a7bca8 Author: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Date: Sun Aug 12 01:39:27 2007 -0400 cpuidle: Remove support for runtime changing of max_cstate Remove support for runtime changeability of max_cstate. Drivers can use use latency APIs. max_cstate can still be used as a boot time option and dmi override. Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Len Brown <len.brown@intel.com> commit 0912a44b13adf22f5e3f607d263aed23b4910d7e Author: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Date: Sun Aug 12 01:39:16 2007 -0400 cpuidle: Remove ACPI cstate_limit calls from ipw2100 ipw2100 already has code to use accetable_latency interfaces to limit the C-state. Remove the calls to acpi_set_cstate_limit and acpi_get_cstate_limit as they are redundant. Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Len Brown <len.brown@intel.com> commit c649a76e76be6bff1fd770d0a775798813a3f6e0 Author: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Date: Sun Aug 12 01:35:39 2007 -0400 cpuidle: compile fix for pause and resume functions Fix the compilation failure when cpuidle is not compiled in. Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Acked-by: Adam Belay <adam.belay@novell.com> Signed-off-by: Len Brown <len.brown@intel.com> commit 2305a5920fb8ee6ccec1c62ade05aa8351091d71 Author: Adam Belay <abelay@novell.com> Date: Thu Jul 19 00:49:00 2007 -0400 cpuidle: re-write Some portions have been rewritten to make the code cleaner and lighter weight. The following is a list of changes: 1.) the state name is now included in the sysfs interface 2.) detection, hotplug, and available state modifications are handled by CPUIDLE drivers directly 3.) the CPUIDLE idle handler is only ever installed when at least one cpuidle_device is enabled and ready 4.) the menu governor BM code no longer overflows 5.) the sysfs attributes are now printed as unsigned integers, avoiding negative values 6.) a variety of other small cleanups Also, Idle drivers are no longer swappable during runtime through the CPUIDLE sysfs inteface. On i386 and x86_64 most idle handlers (e.g. poll, mwait, halt, etc.) don't benefit from an infrastructure that supports multiple states, so I think using a more general case idle handler selection mechanism would be cleaner. Signed-off-by: Adam Belay <abelay@novell.com> Acked-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Acked-by: Shaohua Li <shaohua.li@intel.com> Signed-off-by: Len Brown <len.brown@intel.com> commit df25b6b56955714e6e24b574d88d1fd11f0c3ee5 Author: Len Brown <len.brown@intel.com> Date: Tue Jul 24 17:08:21 2007 -0400 cpuidle: fix IA64 buid Signed-off-by: Len Brown <len.brown@intel.com> commit fd6ada4c14488755ff7068860078c437431fbccd Author: Adrian Bunk <bunk@stusta.de> Date: Mon Jul 9 11:33:13 2007 -0700 cpuidle: static make cpuidle_replace_governor() static Signed-off-by: Adrian Bunk <bunk@stusta.de> Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Len Brown <len.brown@intel.com> commit c1d4a2cebcadf2429c0c72e1d29aa2a9684c32e0 Author: Adrian Bunk <bunk@stusta.de> Date: Tue Jul 3 00:54:40 2007 -0400 cpuidle: static This patch makes the needlessly global struct menu_governor static. Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Len Brown <len.brown@intel.com> commit dbf8780c6e8d572c2c273da97ed1cca7608fd999 Author: Andrew Morton <akpm@linux-foundation.org> Date: Tue Jul 3 00:49:14 2007 -0400 export symbol tick_nohz_get_sleep_length ERROR: "tick_nohz_get_sleep_length" [drivers/cpuidle/governors/menu.ko] undefined! ERROR: "tick_nohz_get_idle_jiffies" [drivers/cpuidle/governors/menu.ko] undefined! And please be sure to get your changes to core kernel suitably reviewed. Cc: Adam Belay <abelay@novell.com> Cc: Venki Pallipadi <venkatesh.pallipadi@intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: john stultz <johnstul@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Len Brown <len.brown@intel.com> commit 29f0e248e7017be15f99febf9143a2cef00b2961 Author: Andrew Morton <akpm@linux-foundation.org> Date: Tue Jul 3 00:43:04 2007 -0400 tick.h needs hrtimer.h It uses hrtimers. Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Len Brown <len.brown@intel.com> commit e40cede7d63a029e92712a3fe02faee60cc38fb4 Author: Venki Pallipadi <venkatesh.pallipadi@intel.com> Date: Tue Jul 3 00:40:34 2007 -0400 cpuidle: first round of documentation updates Documentation changes based on Pavel's feedback. Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Len Brown <len.brown@intel.com> commit 83b42be2efece386976507555c29e7773a0dfcd1 Author: Venki Pallipadi <venkatesh.pallipadi@intel.com> Date: Tue Jul 3 00:39:25 2007 -0400 cpuidle: add rating to the governors and pick the one with highest rating by default Introduce a governor rating scheme to pick the right governor by default. Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Len Brown <len.brown@intel.com> commit d2a74b8c5e8f22def4709330d4bfc4a29209b71c Author: Venki Pallipadi <venkatesh.pallipadi@intel.com> Date: Tue Jul 3 00:38:08 2007 -0400 cpuidle: make cpuidle sysfs driver governor switch off by default Make default cpuidle sysfs to show current_governor and current_driver in read-only mode. More elaborate available_governors and available_drivers with writeable current_governor and current_driver interface only appear with "cpuidle_sysfs_switch" boot parameter. Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Len Brown <len.brown@intel.com> commit 1f60a0e80bf83cf6b55c8845bbe5596ed8f6307b Author: Venki Pallipadi <venkatesh.pallipadi@intel.com> Date: Tue Jul 3 00:37:00 2007 -0400 cpuidle: menu governor: change the early break condition Change the C-state early break out algorithm in menu governor. We only look at early breakouts that result in wakeups shorter than idle state's target_residency. If such a breakout is frequent enough, eliminate the particular idle state upto a timeout period. Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Len Brown <len.brown@intel.com> commit 45a42095cf64b003b4a69be3ce7f434f97d7af51 Author: Venki Pallipadi <venkatesh.pallipadi@intel.com> Date: Tue Jul 3 00:35:38 2007 -0400 cpuidle: fix uninitialized variable in sysfs routine Fix the uninitialized usage of ret. Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Len Brown <len.brown@intel.com> commit 80dca7cdba3e6ee13eae277660873ab9584eb3be Author: Venki Pallipadi <venkatesh.pallipadi@intel.com> Date: Tue Jul 3 00:34:16 2007 -0400 cpuidle: reenable /proc/acpi//power interface for the time being Keep /proc/acpi/processor/CPU*/power around for a while as powertop depends on it. It will be marked deprecated and removed in future. powertop can use cpuidle interfaces instead. Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Len Brown <len.brown@intel.com> commit 589c37c2646c5e3813a51255a5ee1159cb4c33fc Author: Venki Pallipadi <venkatesh.pallipadi@intel.com> Date: Tue Jul 3 00:32:37 2007 -0400 cpuidle: menu governor and hrtimer compile fix Compile fix for menu governor. Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Len Brown <len.brown@intel.com> commit 0ba80bd9ab3ed304cb4f19b722e4cc6740588b5e Author: Len Brown <len.brown@intel.com> Date: Thu May 31 22:51:43 2007 -0400 cpuidle: build fix - cpuidle vs ipw2100 module ERROR: "acpi_set_cstate_limit" [drivers/net/wireless/ipw2100.ko] undefined! Signed-off-by: Len Brown <len.brown@intel.com> commit d7d8fa7f96a7f7682be7c6cc0cc53fa7a18c3b58 Author: Adam Belay <abelay@novell.com> Date: Sat Mar 24 03:47:07 2007 -0400 cpuidle: add the 'menu' governor Here is my first take at implementing an idle PM governor that takes full advantage of NO_HZ. I call it the 'menu' governor because it considers the full list of idle states before each entry. I've kept the implementation fairly simple. It attempts to guess the next residency time and then chooses a state that would meet at least the break-even point between power savings and entry cost. To this end, it selects the deepest idle state that satisfies the following constraints: 1. If the idle time elapsed since bus master activity was detected is below a threshold (currently 20 ms), then limit the selection to C2-type or above. 2. Do not choose a state with a break-even residency that exceeds the expected time remaining until the next timer interrupt. 3. Do not choose a state with a break-even residency that exceeds the elapsed time between the last pair of break events, excluding timer interrupts. This governor has an advantage over "ladder" governor because it proactively checks how much time remains until the next timer interrupt using the tick infrastructure. Also, it handles device interrupt activity more intelligently by not including timer interrupts in break event calculations. Finally, it doesn't make policy decisions using the number of state entries, which can have variable residency times (NO_HZ makes these potentially very large), and instead only considers sleep time deltas. The menu governor can be selected during runtime using the cpuidle sysfs interface like so: "echo "menu" > /sys/devices/system/cpu/cpuidle/current_governor" Signed-off-by: Adam Belay <abelay@novell.com> Signed-off-by: Len Brown <len.brown@intel.com> commit a4bec7e65aa3b7488b879d971651cc99a6c410fe Author: Adam Belay <abelay@novell.com> Date: Sat Mar 24 03:47:03 2007 -0400 cpuidle: export time until next timer interrupt using NO_HZ Expose information about the time remaining until the next timer interrupt expires by utilizing the dynticks infrastructure. Also modify the main idle loop to allow dynticks to handle non-interrupt break events (e.g. DMA). Finally, expose sleep ticks information to external code. Thomas Gleixner is responsible for much of the code in this patch. However, I've made some additional changes, so I'm probably responsible if there are any bugs or oversights :) Signed-off-by: Adam Belay <abelay@novell.com> Signed-off-by: Len Brown <len.brown@intel.com> commit 2929d8996fbc77f41a5ff86bb67cdde3ca7d2d72 Author: Adam Belay <abelay@novell.com> Date: Sat Mar 24 03:46:58 2007 -0400 cpuidle: governor API changes This patch prepares cpuidle for the menu governor. It adds an optional stage after idle state entry to give the governor an opportunity to check why the state was exited. Also it makes sure the idle loop returns after each state entry, allowing the appropriate dynticks code to run. Signed-off-by: Adam Belay <abelay@novell.com> Signed-off-by: Len Brown <len.brown@intel.com> commit 3a7fd42f9825c3b03e364ca59baa751bb350775f Author: Venki Pallipadi <venkatesh.pallipadi@intel.com> Date: Thu Apr 26 00:03:59 2007 -0700 cpuidle: hang fix Prevent hang on x86-64, when ACPI processor driver is added as a module on a system that does not support C-states. x86-64 expects all idle handlers to enable interrupts before returning from idle handler. This is due to enter_idle(), exit_idle() races. Make cpuidle_idle_call() confirm to this when there is no pm_idle_old. Also, cpuidle look at the return values of attch_driver() and set current_driver to NULL if attach fails on all CPUs. Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Len Brown <len.brown@intel.com> commit 4893339a142afbd5b7c01ffadfd53d14746e858e Author: Shaohua Li <shaohua.li@intel.com> Date: Thu Apr 26 10:40:09 2007 +0800 cpuidle: add support for max_cstate limit With CPUIDLE framework, the max_cstate (to limit max cpu c-state) parameter is ingored. Some systems require it to ignore C2/C3 and some drivers like ipw require it too. Signed-off-by: Shaohua Li <shaohua.li@intel.com> Signed-off-by: Len Brown <len.brown@intel.com> commit 43bbbbe1cb998cbd2df656f55bb3bfe30f30e7d1 Author: Shaohua Li <shaohua.li@intel.com> Date: Thu Apr 26 10:40:13 2007 +0800 cpuidle: add cpuidle_fore_redetect_devices API add cpuidle_force_redetect_devices API, which forces all CPU redetect idle states. Next patch will use it. Signed-off-by: Shaohua Li <shaohua.li@intel.com> Signed-off-by: Len Brown <len.brown@intel.com> commit d1edadd608f24836def5ec483d2edccfb37b1d19 Author: Shaohua Li <shaohua.li@intel.com> Date: Thu Apr 26 10:40:01 2007 +0800 cpuidle: fix sysfs related issue Fix the cpuidle sysfs issue. a. make kobject dynamicaly allocated b. fixed sysfs init issue to avoid suspend/resume issue Signed-off-by: Shaohua Li <shaohua.li@intel.com> Signed-off-by: Len Brown <len.brown@intel.com> commit 7169a5cc0d67b263978859672e86c13c23a5570d Author: Randy Dunlap <randy.dunlap@oracle.com> Date: Wed Mar 28 22:52:53 2007 -0400 cpuidle: 1-bit field must be unsigned A 1-bit bitfield has no room for a sign bit. drivers/cpuidle/governors/ladder.c:54:16: error: dubious bitfield without explicit `signed' or `unsigned' Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Len Brown <len.brown@intel.com> commit 4658620158dc2fbd9e4bcb213c5b6fb5d05ba7d4 Author: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Date: Wed Mar 28 22:52:41 2007 -0400 cpuidle: fix boot hang Patch for cpuidle boot hang reported by Larry Finger here. http://www.ussg.iu.edu/hypermail/linux/kernel/0703.2/2025.html Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Cc: Larry Finger <larry.finger@lwfinger.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Len Brown <len.brown@intel.com> commit c17e168aa6e5fe3851baaae8df2fbc1cf11443a9 Author: Len Brown <len.brown@intel.com> Date: Wed Mar 7 04:37:53 2007 -0500 cpuidle: ladder does not depend on ACPI build fix for CONFIG_ACPI=n In file included from drivers/cpuidle/governors/ladder.c:21: include/acpi/processor.h:88: error: expected specifier-qualifier-list before ‘acpi_integer’ include/acpi/processor.h:106: error: expected specifier-qualifier-list before ‘acpi_integer’ include/acpi/processor.h:168: error: expected specifier-qualifier-list before ‘acpi_handle’ Signed-off-by: Len Brown <len.brown@intel.com> commit 8c91d958246bde68db0c3f0c57b535962ce861cb Author: Adrian Bunk <bunk@stusta.de> Date: Tue Mar 6 02:29:40 2007 -0800 cpuidle: make code static This patch makes the following needlessly global code static: - driver.c: __cpuidle_find_driver() - governor.c: __cpuidle_find_governor() - ladder.c: struct ladder_governor Signed-off-by: Adrian Bunk <bunk@stusta.de> Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Cc: Adam Belay <abelay@novell.com> Cc: Shaohua Li <shaohua.li@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Len Brown <len.brown@intel.com> commit 0c39dc3187094c72c33ab65a64d2017b21f372d2 Author: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Date: Wed Mar 7 02:38:22 2007 -0500 cpu_idle: fix build break This patch fixes a build breakage with !CONFIG_HOTPLUG_CPU and CONFIG_CPU_IDLE. Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Len Brown <len.brown@intel.com> commit 8112e3b115659b07df340ef170515799c0105f82 Author: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Date: Tue Mar 6 02:29:39 2007 -0800 cpuidle: build fix for !CPU_IDLE Fix the compile issues when CPU_IDLE is not configured. Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Cc: Adam Belay <abelay@novell.com> Cc: Shaohua Li <shaohua.li@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Len Brown <len.brown@intel.com> commit 1eb4431e9599cd25e0d9872f3c2c8986821839dd Author: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Date: Thu Feb 22 13:54:57 2007 -0800 cpuidle take2: Basic documentation for cpuidle Documentation for cpuidle infrastructure Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Adam Belay <abelay@novell.com> Signed-off-by: Shaohua Li <shaohua.li@intel.com> Signed-off-by: Len Brown <len.brown@intel.com> commit ef5f15a8b79123a047285ec2e3899108661df779 Author: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Date: Thu Feb 22 13:54:03 2007 -0800 cpuidle take2: Hookup ACPI C-states driver with cpuidle Hookup ACPI C-states onto generic cpuidle infrastructure. drivers/acpi/procesor_idle.c is now a ACPI C-states driver that registers as a driver in cpuidle infrastructure and the policy part is removed from drivers/acpi/processor_idle.c. We use governor in cpuidle instead. Signed-off-by: Shaohua Li <shaohua.li@intel.com> Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Adam Belay <abelay@novell.com> Signed-off-by: Len Brown <len.brown@intel.com> commit 987196fa82d4db52c407e8c9d5dec884ba602183 Author: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Date: Thu Feb 22 13:52:57 2007 -0800 cpuidle take2: Core cpuidle infrastructure Announcing 'cpuidle', a new CPU power management infrastructure to manage idle CPUs in a clean and efficient manner. cpuidle separates out the drivers that can provide support for multiple types of idle states and policy governors that decide on what idle state to use at run time. A cpuidle driver can support multiple idle states based on parameters like varying power consumption, wakeup latency, etc (ACPI C-states for example). A cpuidle governor can be usage model specific (laptop, server, laptop on battery etc). Main advantage of the infrastructure being, it allows independent development of drivers and governors and allows for better CPU power management. A huge thanks to Adam Belay and Shaohua Li who were part of this mini-project since its beginning and are greatly responsible for this patchset. This patch: Core cpuidle infrastructure. Introduces a new abstraction layer for cpuidle: * which manages drivers that can support multiple idles states. Drivers can be generic or particular to specific hardware/platform * allows pluging in multiple policy governors that can take idle state policy decision * The core also has a set of sysfs interfaces with which administrato can know about supported drivers and governors and switch them at run time. Signed-off-by: Adam Belay <abelay@novell.com> Signed-off-by: Shaohua Li <shaohua.li@intel.com> Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Len Brown <len.brown@intel.com> Signed-off-by: Len Brown <len.brown@intel.com>
2007-10-04 06:58:00 +08:00
extern ktime_t tick_nohz_get_sleep_length(void);
extern u64 get_cpu_idle_time_us(int cpu, u64 *last_update_time);
extern u64 get_cpu_iowait_time_us(int cpu, u64 *last_update_time);
#else /* !CONFIG_NO_HZ_COMMON */
static inline int tick_nohz_tick_stopped(void) { return 0; }
nohz: Allow rcu extended quiescent state handling seperately from tick stop It is assumed that rcu won't be used once we switch to tickless mode and until we restart the tick. However this is not always true, as in x86-64 where we dereference the idle notifiers after the tick is stopped. To prepare for fixing this, add two new APIs: tick_nohz_idle_enter_norcu() and tick_nohz_idle_exit_norcu(). If no use of RCU is made in the idle loop between tick_nohz_enter_idle() and tick_nohz_exit_idle() calls, the arch must instead call the new *_norcu() version such that the arch doesn't need to call rcu_idle_enter() and rcu_idle_exit(). Otherwise the arch must call tick_nohz_enter_idle() and tick_nohz_exit_idle() and also call explicitly: - rcu_idle_enter() after its last use of RCU before the CPU is put to sleep. - rcu_idle_exit() before the first use of RCU after the CPU is woken up. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Mike Frysinger <vapier@gentoo.org> Cc: Guan Xuetao <gxt@mprc.pku.edu.cn> Cc: David Miller <davem@davemloft.net> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Hans-Christian Egtvedt <hans-christian.egtvedt@atmel.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Paul Mackerras <paulus@samba.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Paul Mundt <lethal@linux-sh.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2011-10-08 22:01:00 +08:00
static inline void tick_nohz_idle_enter(void) { }
static inline void tick_nohz_idle_exit(void) { }
nohz: Separate out irq exit and idle loop dyntick logic The tick_nohz_stop_sched_tick() function, which tries to delay the next timer tick as long as possible, can be called from two places: - From the idle loop to start the dytick idle mode - From interrupt exit if we have interrupted the dyntick idle mode, so that we reprogram the next tick event in case the irq changed some internal state that requires this action. There are only few minor differences between both that are handled by that function, driven by the ts->inidle cpu variable and the inidle parameter. The whole guarantees that we only update the dyntick mode on irq exit if we actually interrupted the dyntick idle mode, and that we enter in RCU extended quiescent state from idle loop entry only. Split this function into: - tick_nohz_idle_enter(), which sets ts->inidle to 1, enters dynticks idle mode unconditionally if it can, and enters into RCU extended quiescent state. - tick_nohz_irq_exit() which only updates the dynticks idle mode when ts->inidle is set (ie: if tick_nohz_idle_enter() has been called). To maintain symmetry, tick_nohz_restart_sched_tick() has been renamed into tick_nohz_idle_exit(). This simplifies the code and micro-optimize the irq exit path (no need for local_irq_save there). This also prepares for the split between dynticks and rcu extended quiescent state logics. We'll need this split to further fix illegal uses of RCU in extended quiescent states in the idle loop. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Mike Frysinger <vapier@gentoo.org> Cc: Guan Xuetao <gxt@mprc.pku.edu.cn> Cc: David Miller <davem@davemloft.net> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Hans-Christian Egtvedt <hans-christian.egtvedt@atmel.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Paul Mackerras <paulus@samba.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Paul Mundt <lethal@linux-sh.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2011-10-08 00:22:06 +08:00
cpuidle: consolidate 2.6.22 cpuidle branch into one patch commit e5a16b1f9eec0af7cfa0830304b41c1c0833cf9f Author: Len Brown <len.brown@intel.com> Date: Tue Oct 2 23:44:44 2007 -0400 cpuidle: shrink diff processor_idle.c | 440 +++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 429 insertions(+), 11 deletions(-) Signed-off-by: Len Brown <len.brown@intel.com> commit dfbb9d5aedfb18848a3e0d6f6e3e4969febb209c Author: Len Brown <len.brown@intel.com> Date: Wed Sep 26 02:17:55 2007 -0400 cpuidle: reduce diff size Reduces the cpuidle processor_idle.c diff vs 2.6.22 from this processor_idle.c | 2006 ++++++++++++++++++++++++++----------------- 1 file changed, 1219 insertions(+), 787 deletions(-) to this: processor_idle.c | 502 +++++++++++++++++++++++++++++++++++++++---- 1 file changed, 458 insertions(+), 44 deletions(-) ...for the purpose of making the cpuilde patch less invasive and easier to review. no functional changes. build tested only. Signed-off-by: Len Brown <len.brown@intel.com> commit 889172fc915f5a7fe20f35b133cbd205ce69bf6c Author: Venki Pallipadi <venkatesh.pallipadi@intel.com> Date: Thu Sep 13 13:40:05 2007 -0700 cpuidle: Retain old ACPI policy for !CONFIG_CPU_IDLE Retain the old policy in processor_idle, so that when CPU_IDLE is not configured, old C-state policy will still be used. This provides a clean gradual migration path from old ACPI policy to new cpuidle based policy. Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Len Brown <len.brown@intel.com> commit 9544a8181edc7ecc33b3bfd69271571f98ed08bc Author: Venki Pallipadi <venkatesh.pallipadi@intel.com> Date: Thu Sep 13 13:39:17 2007 -0700 cpuidle: Configure governors by default Quoting Len "Do not give an option to users to shoot themselves in the foot". Remove the configurability of ladder and menu governors as they are needed for default policy of cpuidle. That way users will not be able to have cpuidle without any policy loosing all C-state power savings. Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Len Brown <len.brown@intel.com> commit 8975059a2c1e56cfe83d1bcf031bcf4cb39be743 Author: Adam Belay <abelay@novell.com> Date: Tue Aug 21 18:27:07 2007 -0400 CPUIDLE: load ACPI properly when CPUIDLE is disabled Change the registration return codes for when CPUIDLE support is not compiled into the kernel. As a result, the ACPI processor driver will load properly even if CPUIDLE is unavailable. However, it may be possible to cleanup the ACPI processor driver further and eliminate some dead code paths. Signed-off-by: Adam Belay <abelay@novell.com> Acked-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Len Brown <len.brown@intel.com> commit e0322e2b58dd1b12ec669bf84693efe0dc2414a8 Author: Adam Belay <abelay@novell.com> Date: Tue Aug 21 18:26:06 2007 -0400 CPUIDLE: remove cpuidle_get_bm_activity() Remove cpuidle_get_bm_activity() and updates governors accordingly. Signed-off-by: Adam Belay <abelay@novell.com> Acked-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Len Brown <len.brown@intel.com> commit 18a6e770d5c82ba26653e53d240caa617e09e9ab Author: Adam Belay <abelay@novell.com> Date: Tue Aug 21 18:25:58 2007 -0400 CPUIDLE: max_cstate fix Currently max_cstate is limited to 0, resulting in no idle processor power management on ACPI platforms. This patch restores the value to the array size. Signed-off-by: Adam Belay <abelay@novell.com> Acked-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Len Brown <len.brown@intel.com> commit 1fdc0887286179b40ce24bcdbde663172e205ef0 Author: Adam Belay <abelay@novell.com> Date: Tue Aug 21 18:25:40 2007 -0400 CPUIDLE: handle BM detection inside the ACPI Processor driver Update the ACPI processor driver to detect BM activity and limit state entry depth internally, rather than exposing such requirements to CPUIDLE. As a result, CPUIDLE can drop this ACPI-specific interface and become more platform independent. BM activity is now handled much more aggressively than it was in the original implementation, so some testing coverage may be needed to verify that this doesn't introduce any DMA buffer under-run issues. Signed-off-by: Adam Belay <abelay@novell.com> Acked-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Len Brown <len.brown@intel.com> commit 0ef38840db666f48e3cdd2b769da676c57228dd9 Author: Adam Belay <abelay@novell.com> Date: Tue Aug 21 18:25:14 2007 -0400 CPUIDLE: menu governor updates Tweak the menu governor to more effectively handle non-timer break events. Non-timer break events are detected by comparing the actual sleep time to the expected sleep time. In future revisions, it may be more reliable to use the timer data structures directly. Signed-off-by: Adam Belay <abelay@novell.com> Acked-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Len Brown <len.brown@intel.com> commit bb4d74fca63fa96cf3ace644b15ae0f12b7df5a1 Author: Adam Belay <abelay@novell.com> Date: Tue Aug 21 18:24:40 2007 -0400 CPUIDLE: fix 'current_governor' sysfs entry Allow the "current_governor" sysfs entry to properly handle input terminated with '\n'. Signed-off-by: Adam Belay <abelay@novell.com> Acked-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Len Brown <len.brown@intel.com> commit df3c71559bb69b125f1a48971bf0d17f78bbdf47 Author: Len Brown <len.brown@intel.com> Date: Sun Aug 12 02:00:45 2007 -0400 cpuidle: fix IA64 build (again) Signed-off-by: Len Brown <len.brown@intel.com> commit a02064579e3f9530fd31baae16b1fc46b5a7bca8 Author: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Date: Sun Aug 12 01:39:27 2007 -0400 cpuidle: Remove support for runtime changing of max_cstate Remove support for runtime changeability of max_cstate. Drivers can use use latency APIs. max_cstate can still be used as a boot time option and dmi override. Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Len Brown <len.brown@intel.com> commit 0912a44b13adf22f5e3f607d263aed23b4910d7e Author: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Date: Sun Aug 12 01:39:16 2007 -0400 cpuidle: Remove ACPI cstate_limit calls from ipw2100 ipw2100 already has code to use accetable_latency interfaces to limit the C-state. Remove the calls to acpi_set_cstate_limit and acpi_get_cstate_limit as they are redundant. Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Len Brown <len.brown@intel.com> commit c649a76e76be6bff1fd770d0a775798813a3f6e0 Author: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Date: Sun Aug 12 01:35:39 2007 -0400 cpuidle: compile fix for pause and resume functions Fix the compilation failure when cpuidle is not compiled in. Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Acked-by: Adam Belay <adam.belay@novell.com> Signed-off-by: Len Brown <len.brown@intel.com> commit 2305a5920fb8ee6ccec1c62ade05aa8351091d71 Author: Adam Belay <abelay@novell.com> Date: Thu Jul 19 00:49:00 2007 -0400 cpuidle: re-write Some portions have been rewritten to make the code cleaner and lighter weight. The following is a list of changes: 1.) the state name is now included in the sysfs interface 2.) detection, hotplug, and available state modifications are handled by CPUIDLE drivers directly 3.) the CPUIDLE idle handler is only ever installed when at least one cpuidle_device is enabled and ready 4.) the menu governor BM code no longer overflows 5.) the sysfs attributes are now printed as unsigned integers, avoiding negative values 6.) a variety of other small cleanups Also, Idle drivers are no longer swappable during runtime through the CPUIDLE sysfs inteface. On i386 and x86_64 most idle handlers (e.g. poll, mwait, halt, etc.) don't benefit from an infrastructure that supports multiple states, so I think using a more general case idle handler selection mechanism would be cleaner. Signed-off-by: Adam Belay <abelay@novell.com> Acked-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Acked-by: Shaohua Li <shaohua.li@intel.com> Signed-off-by: Len Brown <len.brown@intel.com> commit df25b6b56955714e6e24b574d88d1fd11f0c3ee5 Author: Len Brown <len.brown@intel.com> Date: Tue Jul 24 17:08:21 2007 -0400 cpuidle: fix IA64 buid Signed-off-by: Len Brown <len.brown@intel.com> commit fd6ada4c14488755ff7068860078c437431fbccd Author: Adrian Bunk <bunk@stusta.de> Date: Mon Jul 9 11:33:13 2007 -0700 cpuidle: static make cpuidle_replace_governor() static Signed-off-by: Adrian Bunk <bunk@stusta.de> Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Len Brown <len.brown@intel.com> commit c1d4a2cebcadf2429c0c72e1d29aa2a9684c32e0 Author: Adrian Bunk <bunk@stusta.de> Date: Tue Jul 3 00:54:40 2007 -0400 cpuidle: static This patch makes the needlessly global struct menu_governor static. Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Len Brown <len.brown@intel.com> commit dbf8780c6e8d572c2c273da97ed1cca7608fd999 Author: Andrew Morton <akpm@linux-foundation.org> Date: Tue Jul 3 00:49:14 2007 -0400 export symbol tick_nohz_get_sleep_length ERROR: "tick_nohz_get_sleep_length" [drivers/cpuidle/governors/menu.ko] undefined! ERROR: "tick_nohz_get_idle_jiffies" [drivers/cpuidle/governors/menu.ko] undefined! And please be sure to get your changes to core kernel suitably reviewed. Cc: Adam Belay <abelay@novell.com> Cc: Venki Pallipadi <venkatesh.pallipadi@intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: john stultz <johnstul@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Len Brown <len.brown@intel.com> commit 29f0e248e7017be15f99febf9143a2cef00b2961 Author: Andrew Morton <akpm@linux-foundation.org> Date: Tue Jul 3 00:43:04 2007 -0400 tick.h needs hrtimer.h It uses hrtimers. Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Len Brown <len.brown@intel.com> commit e40cede7d63a029e92712a3fe02faee60cc38fb4 Author: Venki Pallipadi <venkatesh.pallipadi@intel.com> Date: Tue Jul 3 00:40:34 2007 -0400 cpuidle: first round of documentation updates Documentation changes based on Pavel's feedback. Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Len Brown <len.brown@intel.com> commit 83b42be2efece386976507555c29e7773a0dfcd1 Author: Venki Pallipadi <venkatesh.pallipadi@intel.com> Date: Tue Jul 3 00:39:25 2007 -0400 cpuidle: add rating to the governors and pick the one with highest rating by default Introduce a governor rating scheme to pick the right governor by default. Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Len Brown <len.brown@intel.com> commit d2a74b8c5e8f22def4709330d4bfc4a29209b71c Author: Venki Pallipadi <venkatesh.pallipadi@intel.com> Date: Tue Jul 3 00:38:08 2007 -0400 cpuidle: make cpuidle sysfs driver governor switch off by default Make default cpuidle sysfs to show current_governor and current_driver in read-only mode. More elaborate available_governors and available_drivers with writeable current_governor and current_driver interface only appear with "cpuidle_sysfs_switch" boot parameter. Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Len Brown <len.brown@intel.com> commit 1f60a0e80bf83cf6b55c8845bbe5596ed8f6307b Author: Venki Pallipadi <venkatesh.pallipadi@intel.com> Date: Tue Jul 3 00:37:00 2007 -0400 cpuidle: menu governor: change the early break condition Change the C-state early break out algorithm in menu governor. We only look at early breakouts that result in wakeups shorter than idle state's target_residency. If such a breakout is frequent enough, eliminate the particular idle state upto a timeout period. Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Len Brown <len.brown@intel.com> commit 45a42095cf64b003b4a69be3ce7f434f97d7af51 Author: Venki Pallipadi <venkatesh.pallipadi@intel.com> Date: Tue Jul 3 00:35:38 2007 -0400 cpuidle: fix uninitialized variable in sysfs routine Fix the uninitialized usage of ret. Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Len Brown <len.brown@intel.com> commit 80dca7cdba3e6ee13eae277660873ab9584eb3be Author: Venki Pallipadi <venkatesh.pallipadi@intel.com> Date: Tue Jul 3 00:34:16 2007 -0400 cpuidle: reenable /proc/acpi//power interface for the time being Keep /proc/acpi/processor/CPU*/power around for a while as powertop depends on it. It will be marked deprecated and removed in future. powertop can use cpuidle interfaces instead. Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Len Brown <len.brown@intel.com> commit 589c37c2646c5e3813a51255a5ee1159cb4c33fc Author: Venki Pallipadi <venkatesh.pallipadi@intel.com> Date: Tue Jul 3 00:32:37 2007 -0400 cpuidle: menu governor and hrtimer compile fix Compile fix for menu governor. Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Len Brown <len.brown@intel.com> commit 0ba80bd9ab3ed304cb4f19b722e4cc6740588b5e Author: Len Brown <len.brown@intel.com> Date: Thu May 31 22:51:43 2007 -0400 cpuidle: build fix - cpuidle vs ipw2100 module ERROR: "acpi_set_cstate_limit" [drivers/net/wireless/ipw2100.ko] undefined! Signed-off-by: Len Brown <len.brown@intel.com> commit d7d8fa7f96a7f7682be7c6cc0cc53fa7a18c3b58 Author: Adam Belay <abelay@novell.com> Date: Sat Mar 24 03:47:07 2007 -0400 cpuidle: add the 'menu' governor Here is my first take at implementing an idle PM governor that takes full advantage of NO_HZ. I call it the 'menu' governor because it considers the full list of idle states before each entry. I've kept the implementation fairly simple. It attempts to guess the next residency time and then chooses a state that would meet at least the break-even point between power savings and entry cost. To this end, it selects the deepest idle state that satisfies the following constraints: 1. If the idle time elapsed since bus master activity was detected is below a threshold (currently 20 ms), then limit the selection to C2-type or above. 2. Do not choose a state with a break-even residency that exceeds the expected time remaining until the next timer interrupt. 3. Do not choose a state with a break-even residency that exceeds the elapsed time between the last pair of break events, excluding timer interrupts. This governor has an advantage over "ladder" governor because it proactively checks how much time remains until the next timer interrupt using the tick infrastructure. Also, it handles device interrupt activity more intelligently by not including timer interrupts in break event calculations. Finally, it doesn't make policy decisions using the number of state entries, which can have variable residency times (NO_HZ makes these potentially very large), and instead only considers sleep time deltas. The menu governor can be selected during runtime using the cpuidle sysfs interface like so: "echo "menu" > /sys/devices/system/cpu/cpuidle/current_governor" Signed-off-by: Adam Belay <abelay@novell.com> Signed-off-by: Len Brown <len.brown@intel.com> commit a4bec7e65aa3b7488b879d971651cc99a6c410fe Author: Adam Belay <abelay@novell.com> Date: Sat Mar 24 03:47:03 2007 -0400 cpuidle: export time until next timer interrupt using NO_HZ Expose information about the time remaining until the next timer interrupt expires by utilizing the dynticks infrastructure. Also modify the main idle loop to allow dynticks to handle non-interrupt break events (e.g. DMA). Finally, expose sleep ticks information to external code. Thomas Gleixner is responsible for much of the code in this patch. However, I've made some additional changes, so I'm probably responsible if there are any bugs or oversights :) Signed-off-by: Adam Belay <abelay@novell.com> Signed-off-by: Len Brown <len.brown@intel.com> commit 2929d8996fbc77f41a5ff86bb67cdde3ca7d2d72 Author: Adam Belay <abelay@novell.com> Date: Sat Mar 24 03:46:58 2007 -0400 cpuidle: governor API changes This patch prepares cpuidle for the menu governor. It adds an optional stage after idle state entry to give the governor an opportunity to check why the state was exited. Also it makes sure the idle loop returns after each state entry, allowing the appropriate dynticks code to run. Signed-off-by: Adam Belay <abelay@novell.com> Signed-off-by: Len Brown <len.brown@intel.com> commit 3a7fd42f9825c3b03e364ca59baa751bb350775f Author: Venki Pallipadi <venkatesh.pallipadi@intel.com> Date: Thu Apr 26 00:03:59 2007 -0700 cpuidle: hang fix Prevent hang on x86-64, when ACPI processor driver is added as a module on a system that does not support C-states. x86-64 expects all idle handlers to enable interrupts before returning from idle handler. This is due to enter_idle(), exit_idle() races. Make cpuidle_idle_call() confirm to this when there is no pm_idle_old. Also, cpuidle look at the return values of attch_driver() and set current_driver to NULL if attach fails on all CPUs. Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Len Brown <len.brown@intel.com> commit 4893339a142afbd5b7c01ffadfd53d14746e858e Author: Shaohua Li <shaohua.li@intel.com> Date: Thu Apr 26 10:40:09 2007 +0800 cpuidle: add support for max_cstate limit With CPUIDLE framework, the max_cstate (to limit max cpu c-state) parameter is ingored. Some systems require it to ignore C2/C3 and some drivers like ipw require it too. Signed-off-by: Shaohua Li <shaohua.li@intel.com> Signed-off-by: Len Brown <len.brown@intel.com> commit 43bbbbe1cb998cbd2df656f55bb3bfe30f30e7d1 Author: Shaohua Li <shaohua.li@intel.com> Date: Thu Apr 26 10:40:13 2007 +0800 cpuidle: add cpuidle_fore_redetect_devices API add cpuidle_force_redetect_devices API, which forces all CPU redetect idle states. Next patch will use it. Signed-off-by: Shaohua Li <shaohua.li@intel.com> Signed-off-by: Len Brown <len.brown@intel.com> commit d1edadd608f24836def5ec483d2edccfb37b1d19 Author: Shaohua Li <shaohua.li@intel.com> Date: Thu Apr 26 10:40:01 2007 +0800 cpuidle: fix sysfs related issue Fix the cpuidle sysfs issue. a. make kobject dynamicaly allocated b. fixed sysfs init issue to avoid suspend/resume issue Signed-off-by: Shaohua Li <shaohua.li@intel.com> Signed-off-by: Len Brown <len.brown@intel.com> commit 7169a5cc0d67b263978859672e86c13c23a5570d Author: Randy Dunlap <randy.dunlap@oracle.com> Date: Wed Mar 28 22:52:53 2007 -0400 cpuidle: 1-bit field must be unsigned A 1-bit bitfield has no room for a sign bit. drivers/cpuidle/governors/ladder.c:54:16: error: dubious bitfield without explicit `signed' or `unsigned' Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Len Brown <len.brown@intel.com> commit 4658620158dc2fbd9e4bcb213c5b6fb5d05ba7d4 Author: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Date: Wed Mar 28 22:52:41 2007 -0400 cpuidle: fix boot hang Patch for cpuidle boot hang reported by Larry Finger here. http://www.ussg.iu.edu/hypermail/linux/kernel/0703.2/2025.html Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Cc: Larry Finger <larry.finger@lwfinger.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Len Brown <len.brown@intel.com> commit c17e168aa6e5fe3851baaae8df2fbc1cf11443a9 Author: Len Brown <len.brown@intel.com> Date: Wed Mar 7 04:37:53 2007 -0500 cpuidle: ladder does not depend on ACPI build fix for CONFIG_ACPI=n In file included from drivers/cpuidle/governors/ladder.c:21: include/acpi/processor.h:88: error: expected specifier-qualifier-list before ‘acpi_integer’ include/acpi/processor.h:106: error: expected specifier-qualifier-list before ‘acpi_integer’ include/acpi/processor.h:168: error: expected specifier-qualifier-list before ‘acpi_handle’ Signed-off-by: Len Brown <len.brown@intel.com> commit 8c91d958246bde68db0c3f0c57b535962ce861cb Author: Adrian Bunk <bunk@stusta.de> Date: Tue Mar 6 02:29:40 2007 -0800 cpuidle: make code static This patch makes the following needlessly global code static: - driver.c: __cpuidle_find_driver() - governor.c: __cpuidle_find_governor() - ladder.c: struct ladder_governor Signed-off-by: Adrian Bunk <bunk@stusta.de> Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Cc: Adam Belay <abelay@novell.com> Cc: Shaohua Li <shaohua.li@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Len Brown <len.brown@intel.com> commit 0c39dc3187094c72c33ab65a64d2017b21f372d2 Author: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Date: Wed Mar 7 02:38:22 2007 -0500 cpu_idle: fix build break This patch fixes a build breakage with !CONFIG_HOTPLUG_CPU and CONFIG_CPU_IDLE. Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Len Brown <len.brown@intel.com> commit 8112e3b115659b07df340ef170515799c0105f82 Author: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Date: Tue Mar 6 02:29:39 2007 -0800 cpuidle: build fix for !CPU_IDLE Fix the compile issues when CPU_IDLE is not configured. Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Cc: Adam Belay <abelay@novell.com> Cc: Shaohua Li <shaohua.li@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Len Brown <len.brown@intel.com> commit 1eb4431e9599cd25e0d9872f3c2c8986821839dd Author: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Date: Thu Feb 22 13:54:57 2007 -0800 cpuidle take2: Basic documentation for cpuidle Documentation for cpuidle infrastructure Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Adam Belay <abelay@novell.com> Signed-off-by: Shaohua Li <shaohua.li@intel.com> Signed-off-by: Len Brown <len.brown@intel.com> commit ef5f15a8b79123a047285ec2e3899108661df779 Author: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Date: Thu Feb 22 13:54:03 2007 -0800 cpuidle take2: Hookup ACPI C-states driver with cpuidle Hookup ACPI C-states onto generic cpuidle infrastructure. drivers/acpi/procesor_idle.c is now a ACPI C-states driver that registers as a driver in cpuidle infrastructure and the policy part is removed from drivers/acpi/processor_idle.c. We use governor in cpuidle instead. Signed-off-by: Shaohua Li <shaohua.li@intel.com> Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Adam Belay <abelay@novell.com> Signed-off-by: Len Brown <len.brown@intel.com> commit 987196fa82d4db52c407e8c9d5dec884ba602183 Author: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Date: Thu Feb 22 13:52:57 2007 -0800 cpuidle take2: Core cpuidle infrastructure Announcing 'cpuidle', a new CPU power management infrastructure to manage idle CPUs in a clean and efficient manner. cpuidle separates out the drivers that can provide support for multiple types of idle states and policy governors that decide on what idle state to use at run time. A cpuidle driver can support multiple idle states based on parameters like varying power consumption, wakeup latency, etc (ACPI C-states for example). A cpuidle governor can be usage model specific (laptop, server, laptop on battery etc). Main advantage of the infrastructure being, it allows independent development of drivers and governors and allows for better CPU power management. A huge thanks to Adam Belay and Shaohua Li who were part of this mini-project since its beginning and are greatly responsible for this patchset. This patch: Core cpuidle infrastructure. Introduces a new abstraction layer for cpuidle: * which manages drivers that can support multiple idles states. Drivers can be generic or particular to specific hardware/platform * allows pluging in multiple policy governors that can take idle state policy decision * The core also has a set of sysfs interfaces with which administrato can know about supported drivers and governors and switch them at run time. Signed-off-by: Adam Belay <abelay@novell.com> Signed-off-by: Shaohua Li <shaohua.li@intel.com> Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Len Brown <len.brown@intel.com> Signed-off-by: Len Brown <len.brown@intel.com>
2007-10-04 06:58:00 +08:00
static inline ktime_t tick_nohz_get_sleep_length(void)
{
ktime_t len = { .tv64 = NSEC_PER_SEC/HZ };
return len;
}
static inline u64 get_cpu_idle_time_us(int cpu, u64 *unused) { return -1; }
static inline u64 get_cpu_iowait_time_us(int cpu, u64 *unused) { return -1; }
#endif /* !CONFIG_NO_HZ_COMMON */
#ifdef CONFIG_NO_HZ_FULL
extern bool tick_nohz_full_running;
extern cpumask_var_t tick_nohz_full_mask;
extern cpumask_var_t housekeeping_mask;
static inline bool tick_nohz_full_enabled(void)
{
if (!context_tracking_is_enabled())
return false;
return tick_nohz_full_running;
}
static inline bool tick_nohz_full_cpu(int cpu)
{
if (!tick_nohz_full_enabled())
return false;
return cpumask_test_cpu(cpu, tick_nohz_full_mask);
}
static inline void tick_nohz_full_add_cpus_to(struct cpumask *mask)
{
if (tick_nohz_full_enabled())
cpumask_or(mask, mask, tick_nohz_full_mask);
}
extern void __tick_nohz_full_check(void);
nohz: Restore NMI safe local irq work for local nohz kick The local nohz kick is currently used by perf which needs it to be NMI-safe. Recent commit though (7d1311b93e58ed55f3a31cc8f94c4b8fe988a2b9) changed its implementation to fire the local kick using the remote kick API. It was convenient to make the code more generic but the remote kick isn't NMI-safe. As a result: WARNING: CPU: 3 PID: 18062 at kernel/irq_work.c:72 irq_work_queue_on+0x11e/0x140() CPU: 3 PID: 18062 Comm: trinity-subchil Not tainted 3.16.0+ #34 0000000000000009 00000000903774d1 ffff880244e06c00 ffffffff9a7f1e37 0000000000000000 ffff880244e06c38 ffffffff9a0791dd ffff880244fce180 0000000000000003 ffff880244e06d58 ffff880244e06ef8 0000000000000000 Call Trace: <NMI> [<ffffffff9a7f1e37>] dump_stack+0x4e/0x7a [<ffffffff9a0791dd>] warn_slowpath_common+0x7d/0xa0 [<ffffffff9a07930a>] warn_slowpath_null+0x1a/0x20 [<ffffffff9a17ca1e>] irq_work_queue_on+0x11e/0x140 [<ffffffff9a10a2c7>] tick_nohz_full_kick_cpu+0x57/0x90 [<ffffffff9a186cd5>] __perf_event_overflow+0x275/0x350 [<ffffffff9a184f80>] ? perf_event_task_disable+0xa0/0xa0 [<ffffffff9a01a4cf>] ? x86_perf_event_set_period+0xbf/0x150 [<ffffffff9a187934>] perf_event_overflow+0x14/0x20 [<ffffffff9a020386>] intel_pmu_handle_irq+0x206/0x410 [<ffffffff9a0b54d3>] ? arch_vtime_task_switch+0x63/0x130 [<ffffffff9a01937b>] perf_event_nmi_handler+0x2b/0x50 [<ffffffff9a007b72>] nmi_handle+0xd2/0x390 [<ffffffff9a007aa5>] ? nmi_handle+0x5/0x390 [<ffffffff9a0d131b>] ? lock_release+0xab/0x330 [<ffffffff9a008062>] default_do_nmi+0x72/0x1c0 [<ffffffff9a0c925f>] ? cpuacct_account_field+0xcf/0x200 [<ffffffff9a008268>] do_nmi+0xb8/0x100 Lets fix this by restoring the use of local irq work for the nohz local kick. Reported-by: Catalin Iacob <iacobcatalin@gmail.com> Reported-and-tested-by: Dave Jones <davej@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2014-08-14 00:50:16 +08:00
extern void tick_nohz_full_kick(void);
extern void tick_nohz_full_kick_cpu(int cpu);
extern void tick_nohz_full_kick_all(void);
extern void __tick_nohz_task_switch(struct task_struct *tsk);
nohz: Basic full dynticks interface For extreme usecases such as Real Time or HPC, having the ability to shutdown the tick when a single task runs on a CPU is a desired feature: * Reducing the amount of interrupts improves throughput for CPU-bound tasks. The CPU is less distracted from its real job, from an execution time and from the cache point of views. * This also improve latency response as we have less critical sections. Start with introducing a very simple interface to define full dynticks CPU: use a boot time option defined cpumask through the "nohz_extended=" kernel parameter. CPUs that are part of this range will have their tick shutdown whenever possible: provided they run a single task and they don't do kernel activity that require the periodic tick. These details will be later documented in Documentation/* An online CPU must be kept outside this range to handle the timekeeping. Suggested-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Christoph Lameter <cl@linux.com> Cc: Geoff Levand <geoff@infradead.org> Cc: Gilad Ben Yossef <gilad@benyossef.com> Cc: Hakan Akkan <hakanakkan@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Kevin Hilman <khilman@linaro.org> Cc: Li Zhong <zhong@linux.vnet.ibm.com> Cc: Namhyung Kim <namhyung.kim@lge.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de>
2012-12-19 00:32:19 +08:00
#else
static inline bool tick_nohz_full_enabled(void) { return false; }
static inline bool tick_nohz_full_cpu(int cpu) { return false; }
static inline void tick_nohz_full_add_cpus_to(struct cpumask *mask) { }
static inline void __tick_nohz_full_check(void) { }
static inline void tick_nohz_full_kick_cpu(int cpu) { }
static inline void tick_nohz_full_kick(void) { }
static inline void tick_nohz_full_kick_all(void) { }
static inline void __tick_nohz_task_switch(struct task_struct *tsk) { }
nohz: Basic full dynticks interface For extreme usecases such as Real Time or HPC, having the ability to shutdown the tick when a single task runs on a CPU is a desired feature: * Reducing the amount of interrupts improves throughput for CPU-bound tasks. The CPU is less distracted from its real job, from an execution time and from the cache point of views. * This also improve latency response as we have less critical sections. Start with introducing a very simple interface to define full dynticks CPU: use a boot time option defined cpumask through the "nohz_extended=" kernel parameter. CPUs that are part of this range will have their tick shutdown whenever possible: provided they run a single task and they don't do kernel activity that require the periodic tick. These details will be later documented in Documentation/* An online CPU must be kept outside this range to handle the timekeeping. Suggested-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Christoph Lameter <cl@linux.com> Cc: Geoff Levand <geoff@infradead.org> Cc: Gilad Ben Yossef <gilad@benyossef.com> Cc: Hakan Akkan <hakanakkan@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Kevin Hilman <khilman@linaro.org> Cc: Li Zhong <zhong@linux.vnet.ibm.com> Cc: Namhyung Kim <namhyung.kim@lge.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de>
2012-12-19 00:32:19 +08:00
#endif
static inline bool is_housekeeping_cpu(int cpu)
{
#ifdef CONFIG_NO_HZ_FULL
if (tick_nohz_full_enabled())
return cpumask_test_cpu(cpu, housekeeping_mask);
#endif
return true;
}
static inline void housekeeping_affine(struct task_struct *t)
{
#ifdef CONFIG_NO_HZ_FULL
if (tick_nohz_full_enabled())
set_cpus_allowed_ptr(t, housekeeping_mask);
#endif
}
static inline void tick_nohz_full_check(void)
{
if (tick_nohz_full_enabled())
__tick_nohz_full_check();
}
static inline void tick_nohz_task_switch(struct task_struct *tsk)
{
if (tick_nohz_full_enabled())
__tick_nohz_task_switch(tsk);
}
#endif