Commit 36e40df3 authored by Anna-Maria Behnsen's avatar Anna-Maria Behnsen Committed by Thomas Gleixner
Browse files

timer_migration: Add tracepoints 



The timer pull logic needs proper debugging aids. Add tracepoints so the
hierarchical idle machinery can be diagnosed.

Signed-off-by: default avatarAnna-Maria Behnsen <anna-maria@linutronix.de>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20240222103403.31923-1-anna-maria@linutronix.de
parent 7ee98877

MAINTAINERS

+1 −0
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@@ -17499,6 +17499,7 @@ T: git git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git timers/core 
F:	fs/timerfd.c

F:	include/linux/time_namespace.h

F:	include/linux/timer*

F:	include/trace/events/timer*

F:	kernel/time/*timer*

F:	kernel/time/namespace.c

























include/trace/events/timer_migration.h
0 → 100644



+298
−0






























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/* SPDX-License-Identifier: GPL-2.0-only */



















#undef TRACE_SYSTEM









#define TRACE_SYSTEM timer_migration



















#if !defined(_TRACE_TIMER_MIGRATION_H) || defined(TRACE_HEADER_MULTI_READ)









#define _TRACE_TIMER_MIGRATION_H



















#include <linux/tracepoint.h>



















/* Group events */









TRACE_EVENT(tmigr_group_set,



















	TP_PROTO(struct tmigr_group *group),



















	TP_ARGS(group),



















	TP_STRUCT__entry(









		__field( void *,	group		)









		__field( unsigned int,	lvl		)









		__field( unsigned int,	numa_node	)









	),



















	TP_fast_assign(









		__entry->group		= group;









		__entry->lvl		= group->level;









		__entry->numa_node	= group->numa_node;









	),



















	TP_printk("group=%p lvl=%d numa=%d",









		  __entry->group, __entry->lvl, __entry->numa_node)









);



















TRACE_EVENT(tmigr_connect_child_parent,



















	TP_PROTO(struct tmigr_group *child),



















	TP_ARGS(child),



















	TP_STRUCT__entry(









		__field( void *,	child		)









		__field( void *,	parent		)









		__field( unsigned int,	lvl		)









		__field( unsigned int,	numa_node	)









		__field( unsigned int,	num_children	)









		__field( u32,		childmask	)









	),



















	TP_fast_assign(









		__entry->child		= child;









		__entry->parent		= child->parent;









		__entry->lvl		= child->parent->level;









		__entry->numa_node	= child->parent->numa_node;









		__entry->num_children	= child->parent->num_children;









		__entry->childmask	= child->childmask;









	),



















	TP_printk("group=%p childmask=%0x parent=%p lvl=%d numa=%d num_children=%d",









		  __entry->child,  __entry->childmask, __entry->parent,









		  __entry->lvl, __entry->numa_node, __entry->num_children)









);



















TRACE_EVENT(tmigr_connect_cpu_parent,



















	TP_PROTO(struct tmigr_cpu *tmc),



















	TP_ARGS(tmc),



















	TP_STRUCT__entry(









		__field( void *,	parent		)









		__field( unsigned int,	cpu		)









		__field( unsigned int,	lvl		)









		__field( unsigned int,	numa_node	)









		__field( unsigned int,	num_children	)









		__field( u32,		childmask	)









	),



















	TP_fast_assign(









		__entry->parent		= tmc->tmgroup;









		__entry->cpu		= tmc->cpuevt.cpu;









		__entry->lvl		= tmc->tmgroup->level;









		__entry->numa_node	= tmc->tmgroup->numa_node;









		__entry->num_children	= tmc->tmgroup->num_children;









		__entry->childmask	= tmc->childmask;









	),



















	TP_printk("cpu=%d childmask=%0x parent=%p lvl=%d numa=%d num_children=%d",









		  __entry->cpu,	 __entry->childmask, __entry->parent,









		  __entry->lvl, __entry->numa_node, __entry->num_children)









);



















DECLARE_EVENT_CLASS(tmigr_group_and_cpu,



















	TP_PROTO(struct tmigr_group *group, union tmigr_state state, u32 childmask),



















	TP_ARGS(group, state, childmask),



















	TP_STRUCT__entry(









		__field( void *,	group		)









		__field( void *,	parent		)









		__field( unsigned int,	lvl		)









		__field( unsigned int,	numa_node	)









		__field( u32,		childmask	)









		__field( u8,		active		)









		__field( u8,		migrator	)









	),



















	TP_fast_assign(









		__entry->group		= group;









		__entry->parent		= group->parent;









		__entry->lvl		= group->level;









		__entry->numa_node	= group->numa_node;









		__entry->childmask	= childmask;









		__entry->active		= state.active;









		__entry->migrator	= state.migrator;









	),



















	TP_printk("group=%p lvl=%d numa=%d active=%0x migrator=%0x "









		  "parent=%p childmask=%0x",









		  __entry->group, __entry->lvl, __entry->numa_node,









		  __entry->active, __entry->migrator,









		  __entry->parent, __entry->childmask)









);



















DEFINE_EVENT(tmigr_group_and_cpu, tmigr_group_set_cpu_inactive,



















	TP_PROTO(struct tmigr_group *group, union tmigr_state state, u32 childmask),



















	TP_ARGS(group, state, childmask)









);



















DEFINE_EVENT(tmigr_group_and_cpu, tmigr_group_set_cpu_active,



















	TP_PROTO(struct tmigr_group *group, union tmigr_state state, u32 childmask),



















	TP_ARGS(group, state, childmask)









);



















/* CPU events*/









DECLARE_EVENT_CLASS(tmigr_cpugroup,



















	TP_PROTO(struct tmigr_cpu *tmc),



















	TP_ARGS(tmc),



















	TP_STRUCT__entry(









		__field( u64,		wakeup	)









		__field( void *,	parent	)









		__field( unsigned int,	cpu	)



















	),



















	TP_fast_assign(









		__entry->wakeup		= tmc->wakeup;









		__entry->parent		= tmc->tmgroup;









		__entry->cpu		= tmc->cpuevt.cpu;









	),



















	TP_printk("cpu=%d parent=%p wakeup=%llu", __entry->cpu, __entry->parent, __entry->wakeup)









);



















DEFINE_EVENT(tmigr_cpugroup, tmigr_cpu_new_timer,



















	TP_PROTO(struct tmigr_cpu *tmc),



















	TP_ARGS(tmc)









);



















DEFINE_EVENT(tmigr_cpugroup, tmigr_cpu_active,



















	TP_PROTO(struct tmigr_cpu *tmc),



















	TP_ARGS(tmc)









);



















DEFINE_EVENT(tmigr_cpugroup, tmigr_cpu_online,



















	TP_PROTO(struct tmigr_cpu *tmc),



















	TP_ARGS(tmc)









);



















DEFINE_EVENT(tmigr_cpugroup, tmigr_cpu_offline,



















	TP_PROTO(struct tmigr_cpu *tmc),



















	TP_ARGS(tmc)









);



















DEFINE_EVENT(tmigr_cpugroup, tmigr_handle_remote_cpu,



















	TP_PROTO(struct tmigr_cpu *tmc),



















	TP_ARGS(tmc)









);



















DECLARE_EVENT_CLASS(tmigr_idle,



















	TP_PROTO(struct tmigr_cpu *tmc, u64 nextevt),



















	TP_ARGS(tmc, nextevt),



















	TP_STRUCT__entry(









		__field( u64,		nextevt)









		__field( u64,		wakeup)









		__field( void *,	parent)









		__field( unsigned int,	cpu)









	),



















	TP_fast_assign(









		__entry->nextevt	= nextevt;









		__entry->wakeup		= tmc->wakeup;









		__entry->parent		= tmc->tmgroup;









		__entry->cpu		= tmc->cpuevt.cpu;









	),



















	TP_printk("cpu=%d parent=%p nextevt=%llu wakeup=%llu",









		  __entry->cpu, __entry->parent, __entry->nextevt, __entry->wakeup)









);



















DEFINE_EVENT(tmigr_idle, tmigr_cpu_idle,



















	TP_PROTO(struct tmigr_cpu *tmc, u64 nextevt),



















	TP_ARGS(tmc, nextevt)









);



















DEFINE_EVENT(tmigr_idle, tmigr_cpu_new_timer_idle,



















	TP_PROTO(struct tmigr_cpu *tmc, u64 nextevt),



















	TP_ARGS(tmc, nextevt)









);



















TRACE_EVENT(tmigr_update_events,



















	TP_PROTO(struct tmigr_group *child, struct tmigr_group *group,









		 union tmigr_state childstate,	union tmigr_state groupstate,









		 u64 nextevt),



















	TP_ARGS(child, group, childstate, groupstate, nextevt),



















	TP_STRUCT__entry(









		__field( void *,	child			)









		__field( void *,	group			)









		__field( u64,		nextevt			)









		__field( u64,		group_next_expiry	)









		__field( u64,		child_evt_expiry	)









		__field( unsigned int,	group_lvl		)









		__field( unsigned int,	child_evtcpu		)









		__field( u8,		child_active		)









		__field( u8,		group_active		)









	),



















	TP_fast_assign(









		__entry->child			= child;









		__entry->group			= group;









		__entry->nextevt		= nextevt;









		__entry->group_next_expiry	= group->next_expiry;









		__entry->child_evt_expiry	= child ? child->groupevt.nextevt.expires : 0;









		__entry->group_lvl		= group->level;









		__entry->child_evtcpu		= child ? child->groupevt.cpu : 0;









		__entry->child_active		= childstate.active;









		__entry->group_active		= groupstate.active;









	),



















	TP_printk("child=%p group=%p group_lvl=%d child_active=%0x group_active=%0x "









		  "nextevt=%llu next_expiry=%llu child_evt_expiry=%llu child_evtcpu=%d",









		  __entry->child, __entry->group, __entry->group_lvl, __entry->child_active,









		  __entry->group_active,









		  __entry->nextevt, __entry->group_next_expiry, __entry->child_evt_expiry,









		  __entry->child_evtcpu)









);



















TRACE_EVENT(tmigr_handle_remote,



















	TP_PROTO(struct tmigr_group *group),



















	TP_ARGS(group),



















	TP_STRUCT__entry(









		__field( void * ,	group	)









		__field( unsigned int ,	lvl	)









	),



















	TP_fast_assign(









		__entry->group		= group;









		__entry->lvl		= group->level;









	),



















	TP_printk("group=%p lvl=%d",









		   __entry->group, __entry->lvl)









);



















#endif /*  _TRACE_TIMER_MIGRATION_H */



















/* This part must be outside protection */









#include <trace/define_trace.h>
























kernel/time/timer_migration.c



+26
−0






























Original line number
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@@ -14,6 +14,9 @@







#include "timer_migration.h"









#include "tick-internal.h"



















#define CREATE_TRACE_POINTS









#include <trace/events/timer_migration.h>



















/*









 * The timer migration mechanism is built on a hierarchy of groups. The









 * lowest level group contains CPUs, the next level groups of CPU groups








@@ -663,6 +666,8 @@ static bool tmigr_active_up(struct tmigr_group *group,







	 */









	group->groupevt.ignore = true;



















	trace_tmigr_group_set_cpu_active(group, newstate, childmask);



















	return walk_done;









}


















@@ -672,6 +677,8 @@ static void __tmigr_cpu_activate(struct tmigr_cpu *tmc)

















	data.childmask = tmc->childmask;



















	trace_tmigr_cpu_active(tmc);



















	tmc->cpuevt.ignore = true;









	WRITE_ONCE(tmc->wakeup, KTIME_MAX);


















@@ -829,6 +836,9 @@ bool tmigr_update_events(struct tmigr_group *group, struct tmigr_group *child,







		data->firstexp = tmigr_next_groupevt_expires(group);









	}



















	trace_tmigr_update_events(child, group, childstate, groupstate,









				  nextexp);



















unlock:









	raw_spin_unlock(&group->lock);


















@@ -863,6 +873,8 @@ static u64 tmigr_new_timer(struct tmigr_cpu *tmc, u64 nextexp)







	if (tmc->remote)









		return KTIME_MAX;



















	trace_tmigr_cpu_new_timer(tmc);



















	tmc->cpuevt.ignore = false;









	data.remote = false;


















@@ -904,6 +916,8 @@ static void tmigr_handle_remote_cpu(unsigned int cpu, u64 now,







		return;









	}



















	trace_tmigr_handle_remote_cpu(tmc);



















	tmc->remote = true;









	WRITE_ONCE(tmc->wakeup, KTIME_MAX);


















@@ -984,6 +998,7 @@ static bool tmigr_handle_remote_up(struct tmigr_group *group,

















	childmask = data->childmask;



















	trace_tmigr_handle_remote(group);









again:









	/*









	 * Handle the group only if @childmask is the migrator or if the








@@ -1206,6 +1221,7 @@ u64 tmigr_cpu_new_timer(u64 nextexp)







	 */









	WRITE_ONCE(tmc->wakeup, ret);



















	trace_tmigr_cpu_new_timer_idle(tmc, nextexp);









	raw_spin_unlock(&tmc->lock);









	return ret;









}








@@ -1298,6 +1314,8 @@ static bool tmigr_inactive_up(struct tmigr_group *group,







	 */









	WARN_ON_ONCE(data->firstexp != KTIME_MAX && group->parent);



















	trace_tmigr_group_set_cpu_inactive(group, newstate, childmask);



















	return walk_done;









}


















@@ -1350,6 +1368,7 @@ u64 tmigr_cpu_deactivate(u64 nextexp)







	 */









	WRITE_ONCE(tmc->wakeup, ret);



















	trace_tmigr_cpu_idle(tmc, nextexp);









	raw_spin_unlock(&tmc->lock);









	return ret;









}








@@ -1467,6 +1486,7 @@ static struct tmigr_group *tmigr_get_group(unsigned int cpu, int node,

















	/* Setup successful. Add it to the hierarchy */









	list_add(&group->list, &tmigr_level_list[lvl]);









	trace_tmigr_group_set(group);









	return group;









}


















@@ -1484,6 +1504,8 @@ static void tmigr_connect_child_parent(struct tmigr_group *child,







	raw_spin_unlock(&parent->lock);









	raw_spin_unlock_irq(&child->lock);



















	trace_tmigr_connect_child_parent(child);



















	/*









	 * To prevent inconsistent states, active children need to be active in









	 * the new parent as well. Inactive children are already marked inactive








@@ -1575,6 +1597,8 @@ static int tmigr_setup_groups(unsigned int cpu, unsigned int node)

















			raw_spin_unlock_irq(&group->lock);



















			trace_tmigr_connect_cpu_parent(tmc);



















			/* There are no children that need to be connected */









			continue;









		} else {








@@ -1642,6 +1666,7 @@ static int tmigr_cpu_online(unsigned int cpu)







		WRITE_ONCE(tmc->wakeup, KTIME_MAX);









	}









	raw_spin_lock_irq(&tmc->lock);









	trace_tmigr_cpu_online(tmc);









	tmc->idle = timer_base_is_idle();









	if (!tmc->idle)









		__tmigr_cpu_activate(tmc);








@@ -1681,6 +1706,7 @@ static int tmigr_cpu_offline(unsigned int cpu)







	 * offline; Therefore nextevt value is set to KTIME_MAX









	 */









	firstexp = __tmigr_cpu_deactivate(tmc, KTIME_MAX);









	trace_tmigr_cpu_offline(tmc);









	raw_spin_unlock_irq(&tmc->lock);



















	if (firstexp != KTIME_MAX) {