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| * | | | hrtimer: Allow concurrent hrtimer_start() for self restarting timersPeter Zijlstra2015-04-221-3/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Because we drop cpu_base->lock around calling hrtimer::function, it is possible for hrtimer_start() to come in between and enqueue the timer. If hrtimer::function then returns HRTIMER_RESTART we'll hit the BUG_ON because HRTIMER_STATE_ENQUEUED will be set. Since the above is a perfectly valid scenario, remove the BUG_ON and make the enqueue_hrtimer() call conditional on the timer not being enqueued already. NOTE: in that concurrent scenario its entirely common for both sites to want to modify the hrtimer, since hrtimers don't provide serialization themselves be sure to provide some such that the hrtimer::function and the hrtimer_start() caller don't both try and fudge the expiration state at the same time. To that effect, add a WARN when someone tries to forward an already enqueued timer, the most common way to change the expiry of self restarting timers. Ideally we'd put the WARN in everything modifying the expiry but most of that is inlines and we don't need the bloat. Fixes: 2d44ae4d7135 ("hrtimer: clean up cpu->base locking tricks") Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Ben Segall <bsegall@google.com> Cc: Roman Gushchin <klamm@yandex-team.ru> Cc: Paul Turner <pjt@google.com> Link: http://lkml.kernel.org/r/20150415113105.GT5029@twins.programming.kicks-ass.net Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | | | timer: Put usleep_range into the __sched sectionThomas Gleixner2015-04-221-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | do_usleep_range() and schedule_hrtimeout_range() are __sched as well. So it makes no sense to have the exported function in a different section. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Link: http://lkml.kernel.org/r/20150414203503.833709502@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | | | timer: Remove pointless return value of do_usleep_range()Thomas Gleixner2015-04-221-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The only user ignores it anyway and rightfully so. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Link: http://lkml.kernel.org/r/20150414203503.756060258@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | | | hrtimer: Avoid locking in hrtimer_cancel() if timer not activeThomas Gleixner2015-04-221-0/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We can do a lockless check for hrtimer_active before actually taking the lock in hrtimer[_try_to]_cancel. This is useful for hotpath users like nanosleep as they avoid the lock dance when the timer has expired. This is safe because active is true when the timer is enqueued or the callback is running. Taking the hrtimer base lock does not protect against concurrent hrtimer_start calls, the callsite has to do the proper serialization itself. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Link: http://lkml.kernel.org/r/20150414203503.580273114@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | | | hrtimer: Remove hrtimer_start() return valueThomas Gleixner2015-04-221-16/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | No user was ever interested whether the timer was active or not when it was started. All abusers of the return value are gone, so get rid of it. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Link: http://lkml.kernel.org/r/20150414203503.483556394@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | | | tick: broadcast-hrtimer: Remove overly clever return value abuseThomas Gleixner2015-04-221-3/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The assignment of bc_moved in the conditional construct relies on the fact that in the case of hrtimer_start() invocation the return value is always 0. It took me a while to understand it. We want to get rid of the hrtimer_start() return value. Open code the logic which makes it readable as well. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Preeti U Murthy <preeti@linux.vnet.ibm.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Link: http://lkml.kernel.org/r/20150414203503.404751457@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | | | alarmtimer: Get rid of unused return valueThomas Gleixner2015-04-221-7/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We want to get rid of the hrtimer_start() return value and the alarm timer return value is nowhere used. Remove it. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: John Stultz <john.stultz@linaro.org> Link: http://lkml.kernel.org/r/20150414203503.243910615@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | | | hrtimer: Remove bogus hrtimer_active() checkThomas Gleixner2015-04-221-4/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The check for hrtimer_active() after starting the timer is pointless. If the timer is inactive it has expired already and therefor the task pointer is already NULL. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Link: http://lkml.kernel.org/r/20150414203502.907149271@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | | | hrtimer: Make hrtimer_start() a inline wrapperThomas Gleixner2015-04-221-19/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | No point for an extra export just to set the extra argument of hrtimer_start_range_ns() to 0. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Link: http://lkml.kernel.org/r/20150414203502.808544539@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | | | hrtimer: Get rid of __hrtimer_start_range_ns()Thomas Gleixner2015-04-221-23/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | No more callers. Remove the leftovers. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Link: http://lkml.kernel.org/r/20150414203502.707871492@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | | | tick: Nohz: Rework next timer evaluationThomas Gleixner2015-04-226-109/+93
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The evaluation of the next timer in the nohz code is based on jiffies while all the tick internals are nano seconds based. We have also to convert hrtimer nanoseconds to jiffies in the !highres case. That's just wrong and introduces interesting corner cases. Turn it around and convert the next timer wheel timer expiry and the rcu event to clock monotonic and base all calculations on nanoseconds. That identifies the case where no timer is pending clearly with an absolute expiry value of KTIME_MAX. Makes the code more readable and gets rid of the jiffies magic in the nohz code. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: John Stultz <john.stultz@linaro.org> Cc: Marcelo Tosatti <mtosatti@redhat.com> Link: http://lkml.kernel.org/r/20150414203502.184198593@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | | | tick: Sched: Restructure codeThomas Gleixner2015-04-221-90/+81
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Get rid of one indentation level. Preparatory patch for a major rework. No functional change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: John Stultz <john.stultz@linaro.org> Cc: Marcelo Tosatti <mtosatti@redhat.com> Link: http://lkml.kernel.org/r/20150414203502.101563235@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | | | tick: sched: Force tick interrupt and get rid of softirq magicThomas Gleixner2015-04-221-54/+29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We already got rid of the hrtimer reprogramming loops and hoops as hrtimer now enforces an interrupt if the enqueued time is in the past. Do the same for the nohz non highres mode. That gets rid of the need to raise the softirq which only serves the purpose of getting the machine out of the inner idle loop. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: John Stultz <john.stultz@linaro.org> Cc: Marcelo Tosatti <mtosatti@redhat.com> Link: http://lkml.kernel.org/r/20150414203502.023464878@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | | | tick: sched: Remove hrtimer_active() checksThomas Gleixner2015-04-221-15/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | hrtimer_start() enforces a timer interrupt if the timer is already expired. Get rid of the checks and the forward loop. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <fweisbec@gmail.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: John Stultz <john.stultz@linaro.org> Cc: Marcelo Tosatti <mtosatti@redhat.com> Link: http://lkml.kernel.org/r/20150414203501.943658239@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | | | hrtimer: Get rid of hrtimer softirqThomas Gleixner2015-04-223-122/+53
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | hrtimer softirq is a leftover from the initial implementation and serves only the purpose to handle the enqueueing of already expired timers in the high resolution timer mode. We discussed whether we change the return value and force all start sites to handle that the timer is already expired, but that would be a Herculean task and I'm not sure whether its a good idea to enforce that handling on everyone. A simpler solution is to enforce a timer interrupt instead of raising and scheduling a softirq. Just use the existing infrastructure to do so and remove all the softirq leftovers. The HRTIMER softirq enum is now unused, but kept around because trace parsers rely on the existing numbering. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Link: http://lkml.kernel.org/r/20150414203501.840834708@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | | | hrtimer: Keep pointer to first timer and simplify __remove_hrtimer()Thomas Gleixner2015-04-221-18/+28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | __remove_hrtimer() needs to evaluate the expiry time to figure out whether the timer which is removed is eventually the first expiring timer on the cpu. Keep a pointer to it, which is lazily updated, so we can avoid the evaluation dance and retrieve the information from there. Generates slightly better code. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Link: http://lkml.kernel.org/r/20150414203501.752838019@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | | | hrtimer: Make use of timerqueue_add/del return valuesThomas Gleixner2015-04-221-4/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use the return value instead of reevaluating the information. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Link: http://lkml.kernel.org/r/20150414203501.658152945@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | | | hrtimer: Use cpu_base->active_base for hotpath iteratorsThomas Gleixner2015-04-221-9/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The active_bases field is guaranteed to be in sync with the timerqueue of the corresponding clock base. So we can use it for iterating over the clock bases. This allows to break out early if no more active clock bases are available and avoids touching the cache lines of inactive clock bases. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Preeti U Murthy <preeti@linux.vnet.ibm.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Link: http://lkml.kernel.org/r/20150414203501.322887675@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | | | hrtimer: Use bits for various boolean indicatorsThomas Gleixner2015-04-221-8/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | No point in wasting 12 byte storage space. Generates better code as well. Text size reduction: x8664 -64, i386 -16, ARM -132, ARM64 -0, power64 -48 Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Link: http://lkml.kernel.org/r/20150414203501.227955358@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | | | hrtimer: Make offset update smarterThomas Gleixner2015-04-223-11/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On every tick/hrtimer interrupt we update the offset variables of the clock bases. That's silly because these offsets change very seldom. Add a sequence counter to the time keeping code which keeps track of the offset updates (clock_was_set()). Have a sequence cache in the hrtimer cpu bases to evaluate whether the offsets must be updated or not. This allows us later to avoid pointless cacheline pollution. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Preeti U Murthy <preeti@linux.vnet.ibm.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: John Stultz <john.stultz@linaro.org> Link: http://lkml.kernel.org/r/20150414203501.132820245@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: John Stultz <john.stultz@linaro.org>
| * | | | hrtimer: Get rid of softirq timeThomas Gleixner2015-04-223-124/+59
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The softirq time field in the clock bases is an optimization from the early days of hrtimers. It provides a coarse "jiffies" like time mostly for self rearming timers. But that comes with a price: - Larger code size - Extra storage space - Duplicated functions with really small differences The benefit of this is optimization is marginal for contemporary systems. Consolidate everything on the high resolution timer implementation. This makes further optimizations possible. Text size reduction: x8664 -95, i386 -356, ARM -148, ARM64 -40, power64 -16 Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Link: http://lkml.kernel.org/r/20150414203501.039977424@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | | | hrtimer: Make the statistics fields smallerThomas Gleixner2015-04-222-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | No point in having usigned long for /proc/timer_list statistics. Make them unsigned int. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Link: http://lkml.kernel.org/r/20150414203500.959773467@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | | | hrtimer: Get rid of hrtimer_get_res()Thomas Gleixner2015-04-223-24/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The resolution is directly accessible now. So its simpler just to fill in the values of the timespec and be done with it. Text size reduction (combined with "hrtimer: Get rid of the resolution field in hrtimer_clock_base"): x8664 -61, i386 -221, ARM -60, power64 -48 Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Link: http://lkml.kernel.org/r/20150414203500.879888080@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | | | hrtimer: Get rid of the resolution field in hrtimer_clock_baseThomas Gleixner2015-04-222-21/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The field has no value because all clock bases have the same resolution. The resolution only changes when we switch to high resolution timer mode. We can evaluate that from a single static variable as well. In the !HIGHRES case its simply a constant. Export the variable, so we can simplify the usage sites. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Preeti U Murthy <preeti@linux.vnet.ibm.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Link: http://lkml.kernel.org/r/20150414203500.645454122@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | | | hrtimer: Update active_bases before calling hrtimer_force_reprogram()Viresh Kumar2015-04-221-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 'active_bases' indicates which clock-base have active timer. The intention of this bit field was to avoid evaluating inactive bases. It was introduced with the introduction of the BOOTTIME and TAI clock bases, but it was never brought into full use. We want to use it now, but in __remove_hrtimer() the update happens after the calling hrtimer_force_reprogram() which has to evaluate all clock bases for the next expiring timer. So in case the last timer of a clock base got removed we still see the active bit and therefor evaluate the clock base for no value. There are further optimizations possible when active_bases is updated in the right place. Move the update before the call to hrtimer_force_reprogram() [ tglx: Massaged changelog ] Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Reviewed-by: Preeti U Murthy <preeti@linux.vnet.ibm.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: linaro-kernel@lists.linaro.org Link: http://lkml.kernel.org/r/20150414203500.533438642@linutronix.de Link: http://lkml.kernel.org/r/c7c8ebcd9ed88bb09d76059c745a1fafb48314e7.1428039899.git.viresh.kumar@linaro.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | | | hrtimer: Document hrtimer_forward[_now]() properThomas Gleixner2015-04-221-0/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Document the calling context conditions. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20150413210035.178751779@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | | | timekeeping: Remove stale function prototypeThomas Gleixner2015-04-221-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 61edec81d260 "timekeeping: Simplify timekeeping_clocktai()" implemented timekeeping_clocktai() as an inline function, but left the old extern prototype in the header file. Remove it. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | | | timer_list: Reduce SEQ_printf footprintJoe Perches2015-04-221-7/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This macro can be converted to a static function to reduce object size. (x86-64 defconfig) $ size kernel/time/timer_list.o* text data bss dec hex filename 6583 8 0 6591 19bf kernel/time/timer_list.o.old 4647 8 0 4655 122f kernel/time/timer_list.o.new Signed-off-by: Joe Perches <joe@perches.com> Cc: John Stultz <john.stultz@linaro.org> Link: http://lkml.kernel.org/r/1429295958.2850.104.camel@perches.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* | | | | Merge branch 'linus' into sched/core, to resolve conflictIngo Molnar2015-06-021-6/+8
|\ \ \ \ \ | | |_|/ / | |/| | | | | | | | | | | | | | | | | | | | | | | Conflicts: arch/sparc/include/asm/topology_64.h Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | | ktime: Fix ktime_divns to do signed divisionJohn Stultz2015-05-131-6/+8
| | |/ / | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It was noted that the 32bit implementation of ktime_divns() was doing unsigned division and didn't properly handle negative values. And when a ktime helper was changed to utilize ktime_divns, it caused a regression on some IR blasters. See the following bugzilla for details: https://bugzilla.redhat.com/show_bug.cgi?id=1200353 This patch fixes the problem in ktime_divns by checking and preserving the sign bit, and then reapplying it if appropriate after the division, it also changes the return type to a s64 to make it more obvious this is expected. Nicolas also pointed out that negative dividers would cause infinite loops on 32bit systems, negative dividers is unlikely for users of this function, but out of caution this patch adds checks for negative dividers for both 32-bit (BUG_ON) and 64-bit(WARN_ON) versions to make sure no such use cases creep in. [ tglx: Hand an u64 to do_div() to avoid the compiler warning ] Fixes: 166afb64511e 'ktime: Sanitize ktime_to_us/ms conversion' Reported-and-tested-by: Trevor Cordes <trevor@tecnopolis.ca> Signed-off-by: John Stultz <john.stultz@linaro.org> Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Josh Boyer <jwboyer@redhat.com> Cc: One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk> Cc: <stable@vger.kernel.org> Link: http://lkml.kernel.org/r/1431118043-23452-1-git-send-email-john.stultz@linaro.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* | | | Merge tag 'v4.1-rc4' into sched/core, before applying new patchesIngo Molnar2015-05-191-5/+1
|\| | | | | | | | | | | | | | | Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | Merge branch 'timers-urgent-for-linus' of ↵Linus Torvalds2015-05-091-5/+1
| |\ \ \ | | |_|/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer fix from Thomas Gleixner: "A simple fix to actually shut down a detached device instead of keeping it active" * 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: clockevents: Shutdown detached clockevent device
| | * | clockevents: Shutdown detached clockevent deviceViresh Kumar2015-04-241-5/+1
| | |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A clockevent device is marked DETACHED when it is replaced by another clockevent device. The device is shutdown properly for drivers that implement legacy ->set_mode() callback, as we call ->set_mode() for CLOCK_EVT_MODE_UNUSED as well. But for the new per-state callback interface, we skip shutting down the device, as we thought its an internal state change. That wasn't correct. The effect is that the device is left programmed in oneshot or periodic mode. Fall-back to 'case CLOCK_EVT_STATE_SHUTDOWN', to shutdown the device. Fixes: bd624d75db21 "clockevents: Introduce mode specific callbacks" Reported-by: Daniel Lezcano <daniel.lezcano@linaro.org> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Cc: linaro-kernel@lists.linaro.org Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/eef0a91c51b74d4e52c8e5a95eca27b5a0563f07.1428650683.git.viresh.kumar@linaro.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* | | sched, timer: Use the atomic task_cputime in thread_group_cputimerJason Low2015-05-081-13/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Recent optimizations were made to thread_group_cputimer to improve its scalability by keeping track of cputime stats without a lock. However, the values were open coded to the structure, causing them to be at a different abstraction level from the regular task_cputime structure. Furthermore, any subsequent similar optimizations would not be able to share the new code, since they are specific to thread_group_cputimer. This patch adds the new task_cputime_atomic data structure (introduced in the previous patch in the series) to thread_group_cputimer for keeping track of the cputime atomically, which also helps generalize the code. Suggested-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Jason Low <jason.low2@hp.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Rik van Riel <riel@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Aswin Chandramouleeswaran <aswin@hp.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Mike Galbraith <umgwanakikbuti@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com> Cc: Scott J Norton <scott.norton@hp.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Waiman Long <Waiman.Long@hp.com> Link: http://lkml.kernel.org/r/1430251224-5764-6-git-send-email-jason.low2@hp.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | sched, timer: Replace spinlocks with atomics in thread_group_cputimer(), to ↵Jason Low2015-05-081-29/+50
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | improve scalability While running a database workload, we found a scalability issue with itimers. Much of the problem was caused by the thread_group_cputimer spinlock. Each time we account for group system/user time, we need to obtain a thread_group_cputimer's spinlock to update the timers. On larger systems (such as a 16 socket machine), this caused more than 30% of total time spent trying to obtain this kernel lock to update these group timer stats. This patch converts the timers to 64-bit atomic variables and use atomic add to update them without a lock. With this patch, the percent of total time spent updating thread group cputimer timers was reduced from 30% down to less than 1%. Note: On 32-bit systems using the generic 64-bit atomics, this causes sample_group_cputimer() to take locks 3 times instead of just 1 time. However, we tested this patch on a 32-bit system ARM system using the generic atomics and did not find the overhead to be much of an issue. An explanation for why this isn't an issue is that 32-bit systems usually have small numbers of CPUs, and cacheline contention from extra spinlocks called periodically is not really apparent on smaller systems. Signed-off-by: Jason Low <jason.low2@hp.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Rik van Riel <riel@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Aswin Chandramouleeswaran <aswin@hp.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Mike Galbraith <umgwanakikbuti@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com> Cc: Scott J Norton <scott.norton@hp.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Waiman Long <Waiman.Long@hp.com> Link: http://lkml.kernel.org/r/1430251224-5764-4-git-send-email-jason.low2@hp.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | sched, timer: Convert usages of ACCESS_ONCE() in the scheduler to ↵Jason Low2015-05-081-4/+4
|/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | READ_ONCE()/WRITE_ONCE() ACCESS_ONCE doesn't work reliably on non-scalar types. This patch removes the rest of the existing usages of ACCESS_ONCE() in the scheduler, and use the new READ_ONCE() and WRITE_ONCE() APIs as appropriate. Signed-off-by: Jason Low <jason.low2@hp.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Rik van Riel <riel@redhat.com> Acked-by: Waiman Long <Waiman.Long@hp.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Aswin Chandramouleeswaran <aswin@hp.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Mike Galbraith <umgwanakikbuti@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com> Cc: Scott J Norton <scott.norton@hp.com> Cc: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/r/1430251224-5764-2-git-send-email-jason.low2@hp.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | Merge tag 'char-misc-4.1-rc1' of ↵Linus Torvalds2015-04-211-1/+1
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc Pull char/misc driver updates from Greg KH: "Here's the big char/misc driver patchset for 4.1-rc1. Lots of different driver subsystem updates here, nothing major, full details are in the shortlog. All of this has been in linux-next for a while" * tag 'char-misc-4.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (133 commits) mei: trace: remove unused TRACE_SYSTEM_STRING DTS: ARM: OMAP3-N900: Add lis3lv02d support Documentation: DT: lis302: update wakeup binding lis3lv02d: DT: add wakeup unit 2 and wakeup threshold lis3lv02d: DT: use s32 to support negative values Drivers: hv: hv_balloon: correctly handle num_pages>INT_MAX case Drivers: hv: hv_balloon: correctly handle val.freeram<num_pages case mei: replace check for connection instead of transitioning mei: use mei_cl_is_connected consistently mei: fix mei_poll operation hv_vmbus: Add gradually increased delay for retries in vmbus_post_msg() Drivers: hv: hv_balloon: survive ballooning request with num_pages=0 Drivers: hv: hv_balloon: eliminate jumps in piecewiese linear floor function Drivers: hv: hv_balloon: do not online pages in offline blocks hv: remove the per-channel workqueue hv: don't schedule new works in vmbus_onoffer()/vmbus_onoffer_rescind() hv: run non-blocking message handlers in the dispatch tasklet coresight: moving to new "hwtracing" directory coresight-tmc: Adding a status interface to sysfs coresight: remove the unnecessary configuration coresight-default-sink ...
| * clockevents: export clockevents_unbind_device instead of clockevents_unbindVitaly Kuznetsov2015-03-011-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It looks like clockevents_unbind is being exported by mistake as: - it is static; - it is not listed in include/linux/clockchips.h; - EXPORT_SYMBOL_GPL(clockevents_unbind) follows clockevents_unbind_device() implementation. I think clockevents_unbind_device should be exported instead. This is going to be used to teardown Hyper-V clockevent devices on module unload. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | timers/PM: Drop unnecessary braces from tick_freeze()Rafael J. Wysocki2015-04-031-3/+2
| | | | | | | | | | | | | | | | | | | | Some braces in tick_freeze() are not necessary, so drop them. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: peterz@infradead.org Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1534128.H5hN3KBFB4@vostro.rjw.lan Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | timers/PM: Fix up tick_unfreeze()Rafael J. Wysocki2015-04-031-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A recent conflict resolution has left tick_resume() in tick_unfreeze() which leads to an unbalanced execution of tick_resume_broadcast() every time that function runs. Fix that by replacing the tick_resume() in tick_unfreeze() with tick_resume_local() as appropriate. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: boris.ostrovsky@oracle.com Cc: david.vrabel@citrix.com Cc: konrad.wilk@oracle.com Cc: peterz@infradead.org Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/8099075.V0LvN3pQAV@vostro.rjw.lan Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | timekeeping: Get rid of stale commentThomas Gleixner2015-04-031-4/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | Arch specific management of xtime/jiffies/wall_to_monotonic is gone for quite a while. Zap the stale comment. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: John Stultz <john.stultz@linaro.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: John Stultz <john.stultz@linaro.org> Link: http://lkml.kernel.org/r/2422730.dmO29q661S@vostro.rjw.lan Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | clockevents: Cleanup dead cpu explicitelyThomas Gleixner2015-04-035-60/+49
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | clockevents_notify() is a leftover from the early design of the clockevents facility. It's really not a notification mechanism, it's a multiplex call. We are way better off to have explicit calls instead of this monstrosity. Split out the cleanup function for a dead cpu and invoke it directly from the cpu down code. Make it conditional on CPU_HOTPLUG as well. Temporary change, will be refined in the future. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> [ Rebased, added clockevents_notify() removal ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1735025.raBZdQHM3m@vostro.rjw.lan Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | clockevents: Make tick handover explicitThomas Gleixner2015-04-034-12/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | clockevents_notify() is a leftover from the early design of the clockevents facility. It's really not a notification mechanism, it's a multiplex call. We are way better off to have explicit calls instead of this monstrosity. Split out the tick_handover call and invoke it explicitely from the hotplug code. Temporary solution will be cleaned up in later patches. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> [ Rebase ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: John Stultz <john.stultz@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/1658173.RkEEILFiQZ@vostro.rjw.lan Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | clockevents: Remove broadcast oneshot control leftoversRafael J. Wysocki2015-04-031-7/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that all users are converted over to explicit calls into the clockevents state machine, remove the notification chain leftovers. Original-from: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: John Stultz <john.stultz@linaro.org> Link: http://lkml.kernel.org/r/14018863.NQUzkFuafr@vostro.rjw.lan Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | clockevents: Provide explicit broadcast oneshot control functionsThomas Gleixner2015-04-033-14/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | clockevents_notify() is a leftover from the early design of the clockevents facility. It's really not a notification mechanism, it's a multiplex call. We are way better off to have explicit calls instead of this monstrosity. Split out the broadcast oneshot control into a separate function and provide inline helpers. Switch clockevents_notify() over. This will go away once all callers are converted. This also gets rid of the nested locking of clockevents_lock and broadcast_lock. The broadcast oneshot control functions do not require clockevents_lock. Only the managing functions (setup/shutdown/suspend/resume of the broadcast device require clockevents_lock. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Alexandre Courbot <gnurou@gmail.com> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Len Brown <lenb@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephen Warren <swarren@wwwdotorg.org> Cc: Thierry Reding <thierry.reding@gmail.com> Cc: Tony Lindgren <tony@atomide.com> Link: http://lkml.kernel.org/r/13000649.8qZuEDV0OA@vostro.rjw.lan Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | clockevents: Remove the broadcast control leftoversThomas Gleixner2015-04-031-10/+0
| | | | | | | | | | | | | | | | | | | | All users converted. Remove the notify leftovers. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/2076318.76XJZ8QYP3@vostro.rjw.lan Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | clockevents: Provide explicit broadcast control functionsThomas Gleixner2015-04-033-38/+32
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | clockevents_notify() is a leftover from the early design of the clockevents facility. It's really not a notification mechanism, it's a multiplex call. We are way better off to have explicit calls instead of this monstrosity. Split out the broadcast control into a separate function and provide inline helpers. Switch clockevents_notify() over. This will go away once all callers are converted. This also gets rid of the nested locking of clockevents_lock and broadcast_lock. The broadcast control functions do not require clockevents_lock. Only the managing functions (setup/shutdown/suspend/resume of the broadcast device require clockevents_lock. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: Len Brown <lenb@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Tony Lindgren <tony@atomide.com> Link: http://lkml.kernel.org/r/8086559.ttsuS0n1Xr@vostro.rjw.lan Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | clocksource: Improve comment explaining clocks_calc_max_nsecs()'s 50% safety ↵John Stultz2015-04-031-2/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | margin Ingo noted that the description of clocks_calc_max_nsecs()'s 50% safety margin was somewhat circular. So this patch tries to improve the comment to better explain what we mean by the 50% safety margin and why we need it. Signed-off-by: John Stultz <john.stultz@linaro.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Prarit Bhargava <prarit@redhat.com> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1427945681-29972-20-git-send-email-john.stultz@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | time, drivers/rtc: Don't bother with rtc_resume() for the nonstop clocksourceXunlei Pang2015-04-031-17/+49
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If a system does not provide a persistent_clock(), the time will be updated on resume by rtc_resume(). With the addition of the non-stop clocksources for suspend timing, those systems set the time on resume in timekeeping_resume(), but may not provide a valid persistent_clock(). This results in the rtc_resume() logic thinking no one has set the time and it then will over-write the suspend time again, which is not necessary and only increases clock error. So, fix this for rtc_resume(). This patch also improves the name of persistent_clock_exist to make it more grammatical. Signed-off-by: Xunlei Pang <pang.xunlei@linaro.org> Signed-off-by: John Stultz <john.stultz@linaro.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1427945681-29972-19-git-send-email-john.stultz@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | time: Fix a bug in timekeeping_suspend() with no persistent clockXunlei Pang2015-04-031-17/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When there's no persistent clock, normally timekeeping_suspend_time should always be zero, but this can break in timekeeping_suspend(). At T1, there was a system suspend, so old_delta was assigned T1. After some time, one time adjustment happened, and xtime got the value of T1-dt(0s<dt<2s). Then, there comes another system suspend soon after this adjustment, obviously we will get a small negative delta_delta, resulting in a negative timekeeping_suspend_time. This is problematic, when doing timekeeping_resume() if there is no nonstop clocksource for example, it will hit the else leg and inject the improper sleeptime which is the wrong logic. So, we can solve this problem by only doing delta related code when the persistent clock is existent. Actually the code only makes sense for persistent clock cases. Signed-off-by: Xunlei Pang <pang.xunlei@linaro.org> Signed-off-by: John Stultz <john.stultz@linaro.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1427945681-29972-18-git-send-email-john.stultz@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
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