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: Anna-Maria Gleixner <[email protected]> Cc: Christoph Hellwig <[email protected]> Cc: John Stultz <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
tadfisher · Jan 16, 2018 · 98ecadd · 98ecadd
1 parent dd934aa
commit 98ecadd
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diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h
@@ -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,
 };
 

diff --git a/include/trace/events/timer.h b/include/trace/events/timer.h
@@ -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

diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c
@@ -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,
+		},
 	}
 };