- 24 7月, 2014 34 次提交
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由 Thomas Gleixner 提交于
The members of the new struct are the required ones for the new NMI safe accessor to clcok monotonic. In order to reuse the existing timekeeping code and to make the update of the fast NMI safe timekeepers a simple memcpy use the struct for the timekeeper as well and convert all users. Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by: NJohn Stultz <john.stultz@linaro.org>
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由 Thomas Gleixner 提交于
Access to time requires to touch two cachelines at minimum 1) The timekeeper data structure 2) The clocksource data structure The access to the clocksource data structure can be avoided as almost all clocksource implementations ignore the argument to the read callback, which is a pointer to the clocksource. But the core needs to touch it to access the members @read and @mask. So we are better off by copying the @read function pointer and the @mask from the clocksource to the core data structure itself. For the most used ktime_get() access all required data including the @read and @mask copies fits together with the sequence counter into a single 64 byte cacheline. For the other time access functions we touch in the current code three cache lines in the worst case. But with the clocksource data copies we can reduce that to two adjacent cachelines, which is more efficient than disjunct cache lines. Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NJohn Stultz <john.stultz@linaro.org>
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由 Thomas Gleixner 提交于
cycle_last was added to the clocksource to support the TSC validation. We moved that to the core code, so we can get rid of the extra copy. Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NJohn Stultz <john.stultz@linaro.org>
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由 Thomas Gleixner 提交于
The only user of the cycle_last validation is the x86 TSC. In order to provide NMI safe accessor functions for clock monotonic and monotonic_raw we need to do that in the core. We can't do the TSC specific if (now < cycle_last) now = cycle_last; for the other wrapping around clocksources, but TSC has CLOCKSOURCE_MASK(64) which actually does not mask out anything so if now is less than cycle_last the subtraction will give a negative result. So we can check for that in clocksource_delta() and return 0 for that case. Implement and enable it for x86 Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NJohn Stultz <john.stultz@linaro.org>
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由 Thomas Gleixner 提交于
We want to move the TSC sanity check into core code to make NMI safe accessors to clock monotonic[_raw] possible. For this we need to sanity check the delta calculation. Create a helper function and convert all sites to use it. [ Build fix from jstultz ] Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NJohn Stultz <john.stultz@linaro.org>
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由 Thomas Gleixner 提交于
Provide a ktime_t based interface for raw monotonic time. Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NJohn Stultz <john.stultz@linaro.org>
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由 Thomas Gleixner 提交于
timekeeping_clocktai() is not used in fast pathes, so the extra timespec conversion is not problematic. Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NJohn Stultz <john.stultz@linaro.org>
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由 Thomas Gleixner 提交于
No more users. Remove it Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NJohn Stultz <john.stultz@linaro.org>
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由 Thomas Gleixner 提交于
Subtracting plain nsec values and converting to timespec is simpler than the whole timespec math. Not really fastpath code, so the division is not an issue. Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NJohn Stultz <john.stultz@linaro.org>
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由 Thomas Gleixner 提交于
get_monotonic_boottime() is not used in fast pathes, so the extra timespec conversion is not problematic. Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NJohn Stultz <john.stultz@linaro.org>
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由 Thomas Gleixner 提交于
No more users. Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NJohn Stultz <john.stultz@linaro.org>
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由 Thomas Gleixner 提交于
Required for moving drivers to the nanosecond based interfaces. Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NJohn Stultz <john.stultz@linaro.org>
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由 Thomas Gleixner 提交于
No more users. Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NJohn Stultz <john.stultz@linaro.org>
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由 Thomas Gleixner 提交于
ktime based conversion function to map a monotonic time stamp to a different CLOCK. Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NJohn Stultz <john.stultz@linaro.org>
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由 Thomas Gleixner 提交于
No need to juggle with timespecs. Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NJohn Stultz <john.stultz@linaro.org>
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由 Thomas Gleixner 提交于
No need to juggle with timespecs. Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NJohn Stultz <john.stultz@linaro.org>
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由 Thomas Gleixner 提交于
Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NJohn Stultz <john.stultz@linaro.org>
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由 Thomas Gleixner 提交于
Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NJohn Stultz <john.stultz@linaro.org>
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由 Thomas Gleixner 提交于
Speed up the readout. Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NJohn Stultz <john.stultz@linaro.org>
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由 Thomas Gleixner 提交于
Provide a helper function which lets us implement ktime_t based interfaces for real, boot and tai clocks. Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NJohn Stultz <john.stultz@linaro.org>
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由 Thomas Gleixner 提交于
Speed up ktime_get() by using ktime_t based data. Text size shrinks by 64 bytes on x8664. Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NJohn Stultz <john.stultz@linaro.org>
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由 Thomas Gleixner 提交于
The ktime_t based interfaces are used a lot in performance critical code pathes. Add ktime_t based data so the interfaces don't have to convert from the xtime/timespec based data. Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NJohn Stultz <john.stultz@linaro.org>
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由 Thomas Gleixner 提交于
We already have a function which does the right thing, that also makes sure that the coming ktime_t based cached values are getting updated. Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NJohn Stultz <john.stultz@linaro.org>
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由 Thomas Gleixner 提交于
struct timekeeper is quite badly sorted for the hot readout path. Most time access functions need to load two cache lines. Rearrange it so ktime_get() and getnstimeofday() are happy with a single cache line. Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NJohn Stultz <john.stultz@linaro.org>
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由 Thomas Gleixner 提交于
No users outside of the core. Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NJohn Stultz <john.stultz@linaro.org>
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由 Thomas Gleixner 提交于
To convert callers of the core code to timespec64 we need to provide the proper interfaces. Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NJohn Stultz <john.stultz@linaro.org>
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由 Thomas Gleixner 提交于
Right now we have time related prototypes in 3 different header files. Move it to a single timekeeping header file and move the core internal stuff into a core private header. Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NJohn Stultz <john.stultz@linaro.org>
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由 John Stultz 提交于
Convert the core timekeeping logic to use timespec64s. This moves the 2038 issues out of the core logic and into all of the accessor functions. Future changes will need to push the timespec64s out to all timekeeping users, but that can be done interface by interface. Signed-off-by: NJohn Stultz <john.stultz@linaro.org> Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NJohn Stultz <john.stultz@linaro.org>
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由 John Stultz 提交于
Helper and conversion functions for timespec64. Signed-off-by: NJohn Stultz <john.stultz@linaro.org> Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NJohn Stultz <john.stultz@linaro.org>
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由 Thomas Gleixner 提交于
With the plain nanoseconds based ktime_t we can simply use ktime_divns() instead of going through loops and hoops of timespec/timeval conversion. Reported-by: NJohn Stultz <john.stultz@linaro.org> Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NJohn Stultz <john.stultz@linaro.org>
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由 John Stultz 提交于
The non-scalar ktime_t implementation is basically a timespec which has to be changed to support dates past 2038 on 32bit systems. This patch removes the non-scalar ktime_t implementation, forcing the scalar s64 nanosecond version on all architectures. This may have additional performance overhead on some 32bit systems when converting between ktime_t and timespec structures, however the majority of 32bit systems (arm and i386) were already using scalar ktime_t, so no performance regressions will be seen on those platforms. On affected platforms, I'm open to finding optimizations, including avoiding converting to timespecs where possible. [ tglx: We can now cleanup the ktime_t.tv64 mess, but thats a different issue and we can throw a coccinelle script at it ] Signed-off-by: NJohn Stultz <john.stultz@linaro.org> Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NJohn Stultz <john.stultz@linaro.org>
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由 John Stultz 提交于
Rather then having two similar but totally different implementations that provide timekeeping state to the hrtimer code, try to unify the two implementations to be more simliar. Thus this clarifies ktime_get_update_offsets to ktime_get_update_offsets_now and changes get_xtime... to ktime_get_update_offsets_tick. Signed-off-by: NJohn Stultz <john.stultz@linaro.org> Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NJohn Stultz <john.stultz@linaro.org>
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由 Thomas Gleixner 提交于
Provide a default stub function instead of having the extra conditional. Cuts binary size on a m68k build by ~100 bytes. Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Acked-by: NGeert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: NJohn Stultz <john.stultz@linaro.org>
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由 David Riley 提交于
Create a module that allows udelay() to be executed to ensure that it is delaying at least as long as requested (with a little bit of error allowed). There are some configurations which don't have reliably udelay due to using a loop delay with cpufreq changes which should use a counter time based delay instead. This test aims to identify those configurations where timing is unreliable. Signed-off-by: NDavid Riley <davidriley@chromium.org> Signed-off-by: NJohn Stultz <john.stultz@linaro.org>
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- 23 6月, 2014 6 次提交
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由 Viresh Kumar 提交于
We call hrtimer_enqueue_reprogram() only when we are in high resolution mode now so we don't need to check that again in hrtimer_enqueue_reprogram(). Once the check is removed, hrtimer_enqueue_reprogram() turns to be an useless wrapper over hrtimer_reprogram() and can be dropped. Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org> Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com> Link: http://lkml.kernel.org/r/1403393357-2070-6-git-send-email-fweisbec@gmail.comSigned-off-by: NThomas Gleixner <tglx@linutronix.de>
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由 Viresh Kumar 提交于
In lowres mode, hrtimers are serviced by the tick instead of a clock event. It works well as long as the tick stays periodic but we must also make sure that the hrtimers are serviced in dynticks mode targets, pretty much like timer list timers do. Note that all dynticks modes are concerned: get_nohz_timer_target() tries not to return remote idle CPUs but there is nothing to prevent the elected target from entering dynticks idle mode until we lock its base. It's also prefectly legal to enqueue hrtimers on full dynticks CPU. So there are two requirements to correctly handle dynticks: 1) On target's tick stop time, we must not delay the next tick further the next hrtimer. 2) On hrtimer queue time. If the tick of the target is stopped, we must wake up that CPU such that it sees the new hrtimer and recalculate the next tick accordingly. The point 1 is well handled currently through get_nohz_timer_interrupt() and cmp_next_hrtimer_event(). But the point 2 isn't handled at all. Fixing this is easy though as we have the necessary API ready for that. All we need is to call wake_up_nohz_cpu() on a target when a newly enqueued hrtimer requires tick rescheduling, like timer list timer do. Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org> Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com> Link: http://lkml.kernel.org/r/3d7ea08ce008698e26bd39fe10f55949391073ab.1403507178.git.viresh.kumar@linaro.orgSigned-off-by: NThomas Gleixner <tglx@linutronix.de>
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由 Viresh Kumar 提交于
In lowres mode, hrtimers are serviced by the tick instead of a clock event. Now it works well as long as the tick stays periodic but we must also make sure that the hrtimers are serviced in dynticks mode. Part of that job consist in kicking a dynticks hrtimer target in order to make it reconsider the next tick to schedule to correctly handle the hrtimer's expiring time. And that part isn't handled by the hrtimers subsystem. To prepare for fixing this, we need __hrtimer_start_range_ns() to be able to resolve the CPU target associated to a hrtimer's object 'cpu_base' so that the kick can be centralized there. So lets store it in the 'struct hrtimer_cpu_base' to resolve the CPU without overhead. It is set once at CPU's online notification. Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org> Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com> Link: http://lkml.kernel.org/r/1403393357-2070-4-git-send-email-fweisbec@gmail.comSigned-off-by: NThomas Gleixner <tglx@linutronix.de>
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由 Viresh Kumar 提交于
When a timer is enqueued or modified on a dynticks target, that CPU must re-evaluate the next tick to service that timer. The tick re-evaluation is performed by an IPI kick on the target. Now while we correctly call wake_up_nohz_cpu() from add_timer_on(), the mod_timer*() API family doesn't support so well dynticks targets. The reason for this is likely that __mod_timer() isn't supposed to select an idle target for a timer, unless that target is the current CPU, in which case a dynticks idle kick isn't actually needed. But there is a small race window lurking behind that assumption: the elected target has all the time to turn dynticks idle between the call to get_nohz_timer_target() and the locking of its base. Hence a risk that we enqueue a timer on a dynticks idle destination without kicking it. As a result, the timer might be serviced too late in the future. Also a target elected by __mod_timer() can be in full dynticks mode and thus require to be kicked as well. And unlike idle dynticks, this concern both local and remote targets. To fix this whole issue, lets centralize the dynticks kick to internal_add_timer() so that it is well handled for all sort of timer enqueue. Even timer migration is concerned so that a full dynticks target is correctly kicked as needed when timers are migrating to it. Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org> Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com> Link: http://lkml.kernel.org/r/1403393357-2070-3-git-send-email-fweisbec@gmail.comSigned-off-by: NThomas Gleixner <tglx@linutronix.de>
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由 Viresh Kumar 提交于
Timers are serviced by the tick. But when a timer is enqueued on a dynticks target, we need to kick it in order to make it reconsider the next tick to schedule to correctly handle the timer's expiring time. Now while this kick is correctly performed for add_timer_on(), the mod_timer*() family has been a bit neglected. To prepare for fixing this, we need internal_add_timer() to be able to resolve the CPU target associated to a timer's object 'base' so that the kick can be centralized there. This can't be passed as an argument as not all the callers know the CPU number of a timer's base. So lets store it in the struct tvec_base to resolve the CPU without much overhead. It is set once for good at every CPU's first boot. Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org> Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com> Link: http://lkml.kernel.org/r/1403393357-2070-2-git-send-email-fweisbec@gmail.comSigned-off-by: NThomas Gleixner <tglx@linutronix.de>
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由 Thomas Gleixner 提交于
Except for Kconfig.HZ. That needs a separate treatment. Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
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