| Message ID | 20220523235332.162966-1-eiichi.tsukata@nutanix.com (mailing list archive) |
|---|---|
| State | Superseded, archived |
| Headers | show |
| Series | [v2] cpuidle: haltpoll: Add trace points for guest_halt_poll_ns grow/shrink | expand |
On Mon, 23 May 2022 23:53:32 +0000 Eiichi Tsukata <eiichi.tsukata@nutanix.com> wrote: > @@ -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(smp_processor_id(), val, old); Why are you passing in smp_processor_id()? > } 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(smp_processor_id(), val, old); > } > } > > diff --git a/include/trace/events/power.h b/include/trace/events/power.h > index af5018aa9517..db065af9c3c0 100644 > --- a/include/trace/events/power.h > +++ b/include/trace/events/power.h > @@ -500,6 +500,39 @@ 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 cpu_id, > + unsigned int new, unsigned int old), > + > + TP_ARGS(grow, cpu_id, new, old), > + > + TP_STRUCT__entry( > + __field(bool, grow) > + __field(unsigned int, cpu_id) > + __field(unsigned int, new) > + __field(unsigned int, old) > + ), > + > + TP_fast_assign( > + __entry->grow = grow; > + __entry->cpu_id = cpu_id; You are wasting space to save the cpu_id, as the trace event already knows what CPU it occurred on. # echo 1 > events/sched/enable # cat trace # TASK-PID CPU# ||||| TIMESTAMP FUNCTION # | | | ||||| | | systemd-1 [004] ..... 15.872715: ftrace_boot_snapshot: ** Boot snapshot taken ** systemd-1 [001] ..... 22.555418: initcall_start: func=fuse_len_args+0x0/0x30 [fuse] systemd-1 [001] ..... 22.555425: initcall_finish: func=fuse_len_args+0x0/0x30 [fuse] ret=0 modprobe-643 [006] ..... 26.737355: initcall_start: func=wmidev_evaluate_method+0x46/0x100 [wmi] modprobe-643 [006] ..... 26.742491: initcall_finish: func=wmidev_evaluate_method+0x46/0x100 [wmi] ret=0 -- Steve > + __entry->new = new; > + __entry->old = old; > + ), > + > + TP_printk("cpu %u: halt_poll_ns %u (%s %u)", > + __entry->cpu_id, > + __entry->new, > + __entry->grow ? "grow" : "shrink", > + __entry->old) > +); > +
On Mon, May 23, 2022 at 11:53:32PM +0000, Eiichi Tsukata wrote: > 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 | 33 ++++++++++++++++++++++++++++ > 2 files changed, 43 insertions(+), 5 deletions(-) > > diff --git a/drivers/cpuidle/governors/haltpoll.c b/drivers/cpuidle/governors/haltpoll.c > index cb2a96eafc02..a5b6ad32956c 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; > Can do it before the assignment: trace_guest_halt_poll_ns_grow(val, dev->poll_limit_ns); > dev->poll_limit_ns = val; > + trace_guest_halt_poll_ns_grow(smp_processor_id(), 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(smp_processor_id(), val, old); > } > } > > diff --git a/include/trace/events/power.h b/include/trace/events/power.h > index af5018aa9517..db065af9c3c0 100644 > --- a/include/trace/events/power.h > +++ b/include/trace/events/power.h > @@ -500,6 +500,39 @@ 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 cpu_id, > + unsigned int new, unsigned int old), > + > + TP_ARGS(grow, cpu_id, new, old), > + > + TP_STRUCT__entry( > + __field(bool, grow) > + __field(unsigned int, cpu_id) > + __field(unsigned int, new) > + __field(unsigned int, old) > + ), > + > + TP_fast_assign( > + __entry->grow = grow; > + __entry->cpu_id = cpu_id; > + __entry->new = new; > + __entry->old = old; > + ), > + > + TP_printk("cpu %u: halt_poll_ns %u (%s %u)", > + __entry->cpu_id, > + __entry->new, > + __entry->grow ? "grow" : "shrink", > + __entry->old) > +); > + > +#define trace_guest_halt_poll_ns_grow(cpu_id, new, old) \ > + trace_guest_halt_poll_ns(true, cpu_id, new, old) > +#define trace_guest_halt_poll_ns_shrink(cpu_id, new, old) \ > + trace_guest_halt_poll_ns(false, cpu_id, new, old) > #endif /* _TRACE_POWER_H */ > > /* This part must be outside protection */ > -- > 2.36.1 > >
Hi Steven > On May 26, 2022, at 1:02, Steven Rostedt <rostedt@goodmis.org> wrote: > > On Mon, 23 May 2022 23:53:32 +0000 > Eiichi Tsukata <eiichi.tsukata@nutanix.com> wrote: > >> @@ -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(smp_processor_id(), val, old); > > Why are you passing in smp_processor_id()? > >> } 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(smp_processor_id(), val, old); >> } >> } >> >> diff --git a/include/trace/events/power.h b/include/trace/events/power.h >> index af5018aa9517..db065af9c3c0 100644 >> --- a/include/trace/events/power.h >> +++ b/include/trace/events/power.h >> @@ -500,6 +500,39 @@ 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 cpu_id, >> + unsigned int new, unsigned int old), >> + >> + TP_ARGS(grow, cpu_id, new, old), >> + >> + TP_STRUCT__entry( >> + __field(bool, grow) >> + __field(unsigned int, cpu_id) >> + __field(unsigned int, new) >> + __field(unsigned int, old) >> + ), >> + >> + TP_fast_assign( >> + __entry->grow = grow; >> + __entry->cpu_id = cpu_id; > > You are wasting space to save the cpu_id, as the trace event already knows > what CPU it occurred on. > > # echo 1 > events/sched/enable > # cat trace > # TASK-PID CPU# ||||| TIMESTAMP FUNCTION > # | | | ||||| | | > systemd-1 [004] ..... 15.872715: ftrace_boot_snapshot: ** Boot snapshot taken ** > systemd-1 [001] ..... 22.555418: initcall_start: func=fuse_len_args+0x0/0x30 [fuse] > systemd-1 [001] ..... 22.555425: initcall_finish: func=fuse_len_args+0x0/0x30 [fuse] ret=0 > modprobe-643 [006] ..... 26.737355: initcall_start: func=wmidev_evaluate_method+0x46/0x100 [wmi] > modprobe-643 [006] ..... 26.742491: initcall_finish: func=wmidev_evaluate_method+0x46/0x100 [wmi] ret=0 > > -- Steve Thanks for your suggestion. I added cpu_id as there is a similar precedent “trace_cpu_idle” but I think we can remove cpu_id. Will fix it in v3. Eiichi
Hi Marcelo > On May 26, 2022, at 2:31, Marcelo Tosatti <mtosatti@redhat.com> wrote: > > On Mon, May 23, 2022 at 11:53:32PM +0000, Eiichi Tsukata wrote: >> 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 | 33 ++++++++++++++++++++++++++++ >> 2 files changed, 43 insertions(+), 5 deletions(-) >> >> diff --git a/drivers/cpuidle/governors/haltpoll.c b/drivers/cpuidle/governors/haltpoll.c >> index cb2a96eafc02..a5b6ad32956c 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; >> > > Can do it before the assignment: > > trace_guest_halt_poll_ns_grow(val, dev->poll_limit_ns); Sure. Will fix it in v4. Thanks Eiichi
diff --git a/drivers/cpuidle/governors/haltpoll.c b/drivers/cpuidle/governors/haltpoll.c index cb2a96eafc02..a5b6ad32956c 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(smp_processor_id(), 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(smp_processor_id(), val, old); } } diff --git a/include/trace/events/power.h b/include/trace/events/power.h index af5018aa9517..db065af9c3c0 100644 --- a/include/trace/events/power.h +++ b/include/trace/events/power.h @@ -500,6 +500,39 @@ 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 cpu_id, + unsigned int new, unsigned int old), + + TP_ARGS(grow, cpu_id, new, old), + + TP_STRUCT__entry( + __field(bool, grow) + __field(unsigned int, cpu_id) + __field(unsigned int, new) + __field(unsigned int, old) + ), + + TP_fast_assign( + __entry->grow = grow; + __entry->cpu_id = cpu_id; + __entry->new = new; + __entry->old = old; + ), + + TP_printk("cpu %u: halt_poll_ns %u (%s %u)", + __entry->cpu_id, + __entry->new, + __entry->grow ? "grow" : "shrink", + __entry->old) +); + +#define trace_guest_halt_poll_ns_grow(cpu_id, new, old) \ + trace_guest_halt_poll_ns(true, cpu_id, new, old) +#define trace_guest_halt_poll_ns_shrink(cpu_id, new, old) \ + trace_guest_halt_poll_ns(false, cpu_id, new, old) #endif /* _TRACE_POWER_H */ /* This part must be outside protection */
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 | 33 ++++++++++++++++++++++++++++ 2 files changed, 43 insertions(+), 5 deletions(-)