From 36e40df35d2c1891fe58241640c7c95de4aa739b Mon Sep 17 00:00:00 2001 From: Anna-Maria Behnsen Date: Thu, 22 Feb 2024 11:34:03 +0100 Subject: 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: Anna-Maria Behnsen Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/r/20240222103403.31923-1-anna-maria@linutronix.de --- kernel/time/timer_migration.c | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+) (limited to 'kernel/time') diff --git a/kernel/time/timer_migration.c b/kernel/time/timer_migration.c index 23cb6ea3d44e..d85aa2afb969 100644 --- a/kernel/time/timer_migration.c +++ b/kernel/time/timer_migration.c @@ -14,6 +14,9 @@ #include "timer_migration.h" #include "tick-internal.h" +#define CREATE_TRACE_POINTS +#include + /* * 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 @@ check_toplvl: 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) { -- cgit v1.2.3