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authorJakub Kicinski <kuba@kernel.org>2023-05-18 14:39:34 -0700
committerJakub Kicinski <kuba@kernel.org>2023-05-18 14:39:34 -0700
commit90223c1136b2930751116fb7de9675f55843f3ad (patch)
treead66d6f6fe5deb321b82ed4efff70e748e8f21df /kernel
parent1ecaf17d097c91a7bd2979c57f7c81c5eeaf526b (diff)
parent1f594fe7c90746982569bd4f3489e809104a9176 (diff)
Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Conflicts: drivers/net/ethernet/freescale/fec_main.c 6ead9c98cafc ("net: fec: remove the xdp_return_frame when lack of tx BDs") 144470c88c5d ("net: fec: using the standard return codes when xdp xmit errors") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/events/core.c14
-rw-r--r--kernel/locking/rwsem.c8
-rw-r--r--kernel/sched/core.c4
-rw-r--r--kernel/time/tick-broadcast.c120
4 files changed, 107 insertions, 39 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 68baa8194d9f..db016e418931 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -10150,8 +10150,20 @@ void perf_tp_event(u16 event_type, u64 count, void *record, int entry_size,
perf_trace_buf_update(record, event_type);
hlist_for_each_entry_rcu(event, head, hlist_entry) {
- if (perf_tp_event_match(event, &data, regs))
+ if (perf_tp_event_match(event, &data, regs)) {
perf_swevent_event(event, count, &data, regs);
+
+ /*
+ * Here use the same on-stack perf_sample_data,
+ * some members in data are event-specific and
+ * need to be re-computed for different sweveents.
+ * Re-initialize data->sample_flags safely to avoid
+ * the problem that next event skips preparing data
+ * because data->sample_flags is set.
+ */
+ perf_sample_data_init(&data, 0, 0);
+ perf_sample_save_raw_data(&data, &raw);
+ }
}
/*
diff --git a/kernel/locking/rwsem.c b/kernel/locking/rwsem.c
index acb5a50309a1..9eabd585ce7a 100644
--- a/kernel/locking/rwsem.c
+++ b/kernel/locking/rwsem.c
@@ -1240,7 +1240,7 @@ static struct rw_semaphore *rwsem_downgrade_wake(struct rw_semaphore *sem)
/*
* lock for reading
*/
-static inline int __down_read_common(struct rw_semaphore *sem, int state)
+static __always_inline int __down_read_common(struct rw_semaphore *sem, int state)
{
int ret = 0;
long count;
@@ -1258,17 +1258,17 @@ out:
return ret;
}
-static inline void __down_read(struct rw_semaphore *sem)
+static __always_inline void __down_read(struct rw_semaphore *sem)
{
__down_read_common(sem, TASK_UNINTERRUPTIBLE);
}
-static inline int __down_read_interruptible(struct rw_semaphore *sem)
+static __always_inline int __down_read_interruptible(struct rw_semaphore *sem)
{
return __down_read_common(sem, TASK_INTERRUPTIBLE);
}
-static inline int __down_read_killable(struct rw_semaphore *sem)
+static __always_inline int __down_read_killable(struct rw_semaphore *sem)
{
return __down_read_common(sem, TASK_KILLABLE);
}
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 944c3ae39861..a68d1276bab0 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -11492,7 +11492,7 @@ void call_trace_sched_update_nr_running(struct rq *rq, int count)
#ifdef CONFIG_SCHED_MM_CID
-/**
+/*
* @cid_lock: Guarantee forward-progress of cid allocation.
*
* Concurrency ID allocation within a bitmap is mostly lock-free. The cid_lock
@@ -11501,7 +11501,7 @@ void call_trace_sched_update_nr_running(struct rq *rq, int count)
*/
DEFINE_RAW_SPINLOCK(cid_lock);
-/**
+/*
* @use_cid_lock: Select cid allocation behavior: lock-free vs spinlock.
*
* When @use_cid_lock is 0, the cid allocation is lock-free. When contention is
diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c
index 93bf2b4e47e5..771d1e040303 100644
--- a/kernel/time/tick-broadcast.c
+++ b/kernel/time/tick-broadcast.c
@@ -35,14 +35,15 @@ static __cacheline_aligned_in_smp DEFINE_RAW_SPINLOCK(tick_broadcast_lock);
#ifdef CONFIG_TICK_ONESHOT
static DEFINE_PER_CPU(struct clock_event_device *, tick_oneshot_wakeup_device);
-static void tick_broadcast_setup_oneshot(struct clock_event_device *bc);
+static void tick_broadcast_setup_oneshot(struct clock_event_device *bc, bool from_periodic);
static void tick_broadcast_clear_oneshot(int cpu);
static void tick_resume_broadcast_oneshot(struct clock_event_device *bc);
# ifdef CONFIG_HOTPLUG_CPU
static void tick_broadcast_oneshot_offline(unsigned int cpu);
# endif
#else
-static inline void tick_broadcast_setup_oneshot(struct clock_event_device *bc) { BUG(); }
+static inline void
+tick_broadcast_setup_oneshot(struct clock_event_device *bc, bool from_periodic) { BUG(); }
static inline void tick_broadcast_clear_oneshot(int cpu) { }
static inline void tick_resume_broadcast_oneshot(struct clock_event_device *bc) { }
# ifdef CONFIG_HOTPLUG_CPU
@@ -264,7 +265,7 @@ int tick_device_uses_broadcast(struct clock_event_device *dev, int cpu)
if (tick_broadcast_device.mode == TICKDEV_MODE_PERIODIC)
tick_broadcast_start_periodic(bc);
else
- tick_broadcast_setup_oneshot(bc);
+ tick_broadcast_setup_oneshot(bc, false);
ret = 1;
} else {
/*
@@ -500,7 +501,7 @@ void tick_broadcast_control(enum tick_broadcast_mode mode)
if (tick_broadcast_device.mode == TICKDEV_MODE_PERIODIC)
tick_broadcast_start_periodic(bc);
else
- tick_broadcast_setup_oneshot(bc);
+ tick_broadcast_setup_oneshot(bc, false);
}
}
out:
@@ -1020,48 +1021,101 @@ static inline ktime_t tick_get_next_period(void)
/**
* tick_broadcast_setup_oneshot - setup the broadcast device
*/
-static void tick_broadcast_setup_oneshot(struct clock_event_device *bc)
+static void tick_broadcast_setup_oneshot(struct clock_event_device *bc,
+ bool from_periodic)
{
int cpu = smp_processor_id();
+ ktime_t nexttick = 0;
if (!bc)
return;
- /* Set it up only once ! */
- if (bc->event_handler != tick_handle_oneshot_broadcast) {
- int was_periodic = clockevent_state_periodic(bc);
-
- bc->event_handler = tick_handle_oneshot_broadcast;
-
+ /*
+ * When the broadcast device was switched to oneshot by the first
+ * CPU handling the NOHZ change, the other CPUs will reach this
+ * code via hrtimer_run_queues() -> tick_check_oneshot_change()
+ * too. Set up the broadcast device only once!
+ */
+ if (bc->event_handler == tick_handle_oneshot_broadcast) {
/*
- * We must be careful here. There might be other CPUs
- * waiting for periodic broadcast. We need to set the
- * oneshot_mask bits for those and program the
- * broadcast device to fire.
+ * The CPU which switched from periodic to oneshot mode
+ * set the broadcast oneshot bit for all other CPUs which
+ * are in the general (periodic) broadcast mask to ensure
+ * that CPUs which wait for the periodic broadcast are
+ * woken up.
+ *
+ * Clear the bit for the local CPU as the set bit would
+ * prevent the first tick_broadcast_enter() after this CPU
+ * switched to oneshot state to program the broadcast
+ * device.
+ *
+ * This code can also be reached via tick_broadcast_control(),
+ * but this cannot avoid the tick_broadcast_clear_oneshot()
+ * as that would break the periodic to oneshot transition of
+ * secondary CPUs. But that's harmless as the below only
+ * clears already cleared bits.
*/
+ tick_broadcast_clear_oneshot(cpu);
+ return;
+ }
+
+
+ bc->event_handler = tick_handle_oneshot_broadcast;
+ bc->next_event = KTIME_MAX;
+
+ /*
+ * When the tick mode is switched from periodic to oneshot it must
+ * be ensured that CPUs which are waiting for periodic broadcast
+ * get their wake-up at the next tick. This is achieved by ORing
+ * tick_broadcast_mask into tick_broadcast_oneshot_mask.
+ *
+ * For other callers, e.g. broadcast device replacement,
+ * tick_broadcast_oneshot_mask must not be touched as this would
+ * set bits for CPUs which are already NOHZ, but not idle. Their
+ * next tick_broadcast_enter() would observe the bit set and fail
+ * to update the expiry time and the broadcast event device.
+ */
+ if (from_periodic) {
cpumask_copy(tmpmask, tick_broadcast_mask);
+ /* Remove the local CPU as it is obviously not idle */
cpumask_clear_cpu(cpu, tmpmask);
- cpumask_or(tick_broadcast_oneshot_mask,
- tick_broadcast_oneshot_mask, tmpmask);
+ cpumask_or(tick_broadcast_oneshot_mask, tick_broadcast_oneshot_mask, tmpmask);
- if (was_periodic && !cpumask_empty(tmpmask)) {
- ktime_t nextevt = tick_get_next_period();
+ /*
+ * Ensure that the oneshot broadcast handler will wake the
+ * CPUs which are still waiting for periodic broadcast.
+ */
+ nexttick = tick_get_next_period();
+ tick_broadcast_init_next_event(tmpmask, nexttick);
- clockevents_switch_state(bc, CLOCK_EVT_STATE_ONESHOT);
- tick_broadcast_init_next_event(tmpmask, nextevt);
- tick_broadcast_set_event(bc, cpu, nextevt);
- } else
- bc->next_event = KTIME_MAX;
- } else {
/*
- * The first cpu which switches to oneshot mode sets
- * the bit for all other cpus which are in the general
- * (periodic) broadcast mask. So the bit is set and
- * would prevent the first broadcast enter after this
- * to program the bc device.
+ * If the underlying broadcast clock event device is
+ * already in oneshot state, then there is nothing to do.
+ * The device was already armed for the next tick
+ * in tick_handle_broadcast_periodic()
*/
- tick_broadcast_clear_oneshot(cpu);
+ if (clockevent_state_oneshot(bc))
+ return;
}
+
+ /*
+ * When switching from periodic to oneshot mode arm the broadcast
+ * device for the next tick.
+ *
+ * If the broadcast device has been replaced in oneshot mode and
+ * the oneshot broadcast mask is not empty, then arm it to expire
+ * immediately in order to reevaluate the next expiring timer.
+ * @nexttick is 0 and therefore in the past which will cause the
+ * clockevent code to force an event.
+ *
+ * For both cases the programming can be avoided when the oneshot
+ * broadcast mask is empty.
+ *
+ * tick_broadcast_set_event() implicitly switches the broadcast
+ * device to oneshot state.
+ */
+ if (!cpumask_empty(tick_broadcast_oneshot_mask))
+ tick_broadcast_set_event(bc, cpu, nexttick);
}
/*
@@ -1070,14 +1124,16 @@ static void tick_broadcast_setup_oneshot(struct clock_event_device *bc)
void tick_broadcast_switch_to_oneshot(void)
{
struct clock_event_device *bc;
+ enum tick_device_mode oldmode;
unsigned long flags;
raw_spin_lock_irqsave(&tick_broadcast_lock, flags);
+ oldmode = tick_broadcast_device.mode;
tick_broadcast_device.mode = TICKDEV_MODE_ONESHOT;
bc = tick_broadcast_device.evtdev;
if (bc)
- tick_broadcast_setup_oneshot(bc);
+ tick_broadcast_setup_oneshot(bc, oldmode == TICKDEV_MODE_PERIODIC);
raw_spin_unlock_irqrestore(&tick_broadcast_lock, flags);
}