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

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

Signed-off-by: Eiichi Tsukata <eiichi.tsukata@nutanix.com>
Acked-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Eiichi Tsukata 2022-05-27 00:53:45 +00:00 committed by Rafael J. Wysocki
parent b13baccc38
commit 0da11bf0ca
2 changed files with 32 additions and 0 deletions
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3
drivers/cpuidle/governors/haltpoll.c
View file

@ -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;
}
}

29
include/trace/events/power.h
View file

@ -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 */