Messages in this thread Patch in this message | | | From | Eiichi Tsukata <> | Subject | [PATCH v3] cpuidle: haltpoll: Add trace points for guest_halt_poll_ns grow/shrink | Date | Thu, 26 May 2022 00:16:59 +0000 |
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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> --- drivers/cpuidle/governors/haltpoll.c | 15 +++++++++----- include/trace/events/power.h | 29 ++++++++++++++++++++++++++++ 2 files changed, 39 insertions(+), 5 deletions(-)
diff --git a/drivers/cpuidle/governors/haltpoll.c b/drivers/cpuidle/governors/haltpoll.c index cb2a96eafc02..4c61ff8f460b 100644 --- a/drivers/cpuidle/governors/haltpoll.c +++ b/drivers/cpuidle/governors/haltpoll.c @@ -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); @@ -77,13 +78,16 @@ static int haltpoll_select(struct cpuidle_driver *drv, static void adjust_poll_limit(struct cpuidle_device *dev, u64 block_ns) { - unsigned int val; + unsigned int val, old; - /* Grow cpu_halt_poll_us if - * cpu_halt_poll_us < block_ns < guest_halt_poll_us + val = dev->poll_limit_ns; + old = val; + + /* Grow poll_limit_ns if + * poll_limit_ns < block_ns < guest_halt_poll_ns */ if (block_ns > dev->poll_limit_ns && block_ns <= guest_halt_poll_ns) { - val = dev->poll_limit_ns * guest_halt_poll_grow; + val *= guest_halt_poll_grow; if (val < guest_halt_poll_grow_start) val = guest_halt_poll_grow_start; @@ -91,16 +95,17 @@ static void adjust_poll_limit(struct cpuidle_device *dev, u64 block_ns) val = guest_halt_poll_ns; dev->poll_limit_ns = val; + trace_guest_halt_poll_ns_grow(val, old); } else if (block_ns > guest_halt_poll_ns && guest_halt_poll_allow_shrink) { unsigned int shrink = guest_halt_poll_shrink; - val = dev->poll_limit_ns; if (shrink == 0) val = 0; else val /= shrink; dev->poll_limit_ns = val; + trace_guest_halt_poll_ns_shrink(val, old); } } diff --git a/include/trace/events/power.h b/include/trace/events/power.h index af5018aa9517..c708521e4ed5 100644 --- a/include/trace/events/power.h +++ b/include/trace/events/power.h @@ -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 */ -- 2.36.1
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