Commit 0da11bf0 authored by Eiichi Tsukata's avatar Eiichi Tsukata Committed by Rafael J. Wysocki
Browse files

cpuidle: haltpoll: Add trace points for guest_halt_poll_ns grow/shrink 



Add trace points as are implemented in KVM host halt polling.
This helps tune guest halt polling params.

Signed-off-by: default avatarEiichi Tsukata <eiichi.tsukata@nutanix.com>
Acked-by: default avatarMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent b13baccc

drivers/cpuidle/governors/haltpoll.c

+3 −0
Original line number Diff line number Diff line
@@ -19,6 +19,7 @@ 
#include <linux/sched.h>

#include <linux/module.h>

#include <linux/kvm_para.h>

#include <trace/events/power.h>



static unsigned int guest_halt_poll_ns __read_mostly = 200000;

module_param(guest_halt_poll_ns, uint, 0644);
@@ -90,6 +91,7 @@ static void adjust_poll_limit(struct cpuidle_device *dev, u64 block_ns) 
		if (val > guest_halt_poll_ns)

			val = guest_halt_poll_ns;



		trace_guest_halt_poll_ns_grow(val, dev->poll_limit_ns);

		dev->poll_limit_ns = val;

	} else if (block_ns > guest_halt_poll_ns &&

		   guest_halt_poll_allow_shrink) {
@@ -100,6 +102,7 @@ static void adjust_poll_limit(struct cpuidle_device *dev, u64 block_ns) 
			val = 0;

		else

			val /= shrink;

		trace_guest_halt_poll_ns_shrink(val, dev->poll_limit_ns);

		dev->poll_limit_ns = val;

	}

}

include/trace/events/power.h

+29 −0
Original line number Diff line number Diff line
@@ -500,6 +500,35 @@ DEFINE_EVENT(dev_pm_qos_request, dev_pm_qos_remove_request, 


	TP_ARGS(name, type, new_value)

);



TRACE_EVENT(guest_halt_poll_ns,



	TP_PROTO(bool grow, unsigned int new, unsigned int old),



	TP_ARGS(grow, new, old),



	TP_STRUCT__entry(

		__field(bool, grow)

		__field(unsigned int, new)

		__field(unsigned int, old)

	),



	TP_fast_assign(

		__entry->grow   = grow;

		__entry->new    = new;

		__entry->old    = old;

	),



	TP_printk("halt_poll_ns %u (%s %u)",

		__entry->new,

		__entry->grow ? "grow" : "shrink",

		__entry->old)

);



#define trace_guest_halt_poll_ns_grow(new, old) \

	trace_guest_halt_poll_ns(true, new, old)

#define trace_guest_halt_poll_ns_shrink(new, old) \

	trace_guest_halt_poll_ns(false, new, old)

#endif /* _TRACE_POWER_H */



/* This part must be outside protection */