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authorAnna-Maria Behnsen <anna-maria@linutronix.de>2024-02-22 11:34:03 +0100
committerThomas Gleixner <tglx@linutronix.de>2024-02-22 17:52:32 +0100
commit36e40df35d2c1891fe58241640c7c95de4aa739b (patch)
tree9b095f2fa1ad661f00b5b157667ce6b7d29d2dd9 /kernel
parenttimers: Implement the hierarchical pull model (diff)
downloadlinux-36e40df35d2c1891fe58241640c7c95de4aa739b.tar.xz
linux-36e40df35d2c1891fe58241640c7c95de4aa739b.zip
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 <anna-maria@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20240222103403.31923-1-anna-maria@linutronix.de
Diffstat (limited to 'kernel')
-rw-r--r--kernel/time/timer_migration.c26
1 files changed, 26 insertions, 0 deletions
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 <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 @@ 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) {