Commit 98ecadd4 authored by Anna-Maria Gleixner's avatar Anna-Maria Gleixner Committed by Ingo Molnar
Browse files

hrtimer: Add clock bases and hrtimer mode for softirq context 



Currently hrtimer callback functions are always executed in hard interrupt
context. Users of hrtimers, which need their timer function to be executed
in soft interrupt context, make use of tasklets to get the proper context.

Add additional hrtimer clock bases for timers which must expire in softirq
context, so the detour via the tasklet can be avoided. This is also
required for RT, where the majority of hrtimer is moved into softirq
hrtimer context.

The selection of the expiry mode happens via a mode bit. Introduce
HRTIMER_MODE_SOFT and the matching combinations with the ABS/REL/PINNED
bits and update the decoding of hrtimer_mode in tracepoints.

Signed-off-by: default avatarAnna-Maria Gleixner <anna-maria@linutronix.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: keescook@chromium.org
Link: http://lkml.kernel.org/r/20171221104205.7269-27-anna-maria@linutronix.de


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent dd934aa8

include/linux/hrtimer.h

+14 −0
Original line number Diff line number Diff line
@@ -33,14 +33,24 @@ struct hrtimer_cpu_base; 
 * HRTIMER_MODE_REL		- Time value is relative to now

 * HRTIMER_MODE_PINNED		- Timer is bound to CPU (is only considered

 *				  when starting the timer)

 * HRTIMER_MODE_SOFT		- Timer callback function will be executed in

 *				  soft irq context

 */

enum hrtimer_mode {

	HRTIMER_MODE_ABS	= 0x00,

	HRTIMER_MODE_REL	= 0x01,

	HRTIMER_MODE_PINNED	= 0x02,

	HRTIMER_MODE_SOFT	= 0x04,



	HRTIMER_MODE_ABS_PINNED = HRTIMER_MODE_ABS | HRTIMER_MODE_PINNED,

	HRTIMER_MODE_REL_PINNED = HRTIMER_MODE_REL | HRTIMER_MODE_PINNED,



	HRTIMER_MODE_ABS_SOFT	= HRTIMER_MODE_ABS | HRTIMER_MODE_SOFT,

	HRTIMER_MODE_REL_SOFT	= HRTIMER_MODE_REL | HRTIMER_MODE_SOFT,



	HRTIMER_MODE_ABS_PINNED_SOFT = HRTIMER_MODE_ABS_PINNED | HRTIMER_MODE_SOFT,

	HRTIMER_MODE_REL_PINNED_SOFT = HRTIMER_MODE_REL_PINNED | HRTIMER_MODE_SOFT,



};



/*
@@ -151,6 +161,10 @@ enum hrtimer_base_type { 
	HRTIMER_BASE_REALTIME,

	HRTIMER_BASE_BOOTTIME,

	HRTIMER_BASE_TAI,

	HRTIMER_BASE_MONOTONIC_SOFT,

	HRTIMER_BASE_REALTIME_SOFT,

	HRTIMER_BASE_BOOTTIME_SOFT,

	HRTIMER_BASE_TAI_SOFT,

	HRTIMER_MAX_CLOCK_BASES,

};

include/trace/events/timer.h

+5 −1
Original line number Diff line number Diff line
@@ -148,7 +148,11 @@ DEFINE_EVENT(timer_class, timer_cancel, 
		{ HRTIMER_MODE_ABS,		"ABS"		},	\

		{ HRTIMER_MODE_REL,		"REL"		},	\

		{ HRTIMER_MODE_ABS_PINNED,	"ABS|PINNED"	},	\

		{ HRTIMER_MODE_REL_PINNED,	"REL|PINNED"	})

		{ HRTIMER_MODE_REL_PINNED,	"REL|PINNED"	},	\

		{ HRTIMER_MODE_ABS_SOFT,	"ABS|SOFT"	},	\

		{ HRTIMER_MODE_REL_SOFT,	"REL|SOFT"	},	\

		{ HRTIMER_MODE_ABS_PINNED_SOFT,	"ABS|PINNED|SOFT" },	\

		{ HRTIMER_MODE_REL_PINNED_SOFT,	"REL|PINNED|SOFT" })



/**

 * hrtimer_init - called when the hrtimer is initialized

kernel/time/hrtimer.c

+20 −0
Original line number Diff line number Diff line
@@ -92,6 +92,26 @@ DEFINE_PER_CPU(struct hrtimer_cpu_base, hrtimer_bases) = 
			.clockid = CLOCK_TAI,

			.get_time = &ktime_get_clocktai,

		},

		{

			.index = HRTIMER_BASE_MONOTONIC_SOFT,

			.clockid = CLOCK_MONOTONIC,

			.get_time = &ktime_get,

		},

		{

			.index = HRTIMER_BASE_REALTIME_SOFT,

			.clockid = CLOCK_REALTIME,

			.get_time = &ktime_get_real,

		},

		{

			.index = HRTIMER_BASE_BOOTTIME_SOFT,

			.clockid = CLOCK_BOOTTIME,

			.get_time = &ktime_get_boottime,

		},

		{

			.index = HRTIMER_BASE_TAI_SOFT,

			.clockid = CLOCK_TAI,

			.get_time = &ktime_get_clocktai,

		},

	}

};

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