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Merge tag 'locking-urgent-2020-08-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

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Pull locking fixes from Thomas Gleixner:
 "A set of fixes for lockdep, tracing and RCU:

   - Prevent recursion by using raw_cpu_* operations

   - Fixup the interrupt state in the cpu idle code to be consistent

   - Push rcu_idle_enter/exit() invocations deeper into the idle path so
     that the lock operations are inside the RCU watching sections

   - Move trace_cpu_idle() into generic code so it's called before RCU
     goes idle.

   - Handle raw_local_irq* vs. local_irq* operations correctly

   - Move the tracepoints out from under the lockdep recursion handling
     which turned out to be fragile and inconsistent"

* tag 'locking-urgent-2020-08-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  lockdep,trace: Expose tracepoints
  lockdep: Only trace IRQ edges
  mips: Implement arch_irqs_disabled()
  arm64: Implement arch_irqs_disabled()
  nds32: Implement arch_irqs_disabled()
  locking/lockdep: Cleanup
  x86/entry: Remove unused THUNKs
  cpuidle: Move trace_cpu_idle() into generic code
  cpuidle: Make CPUIDLE_FLAG_TLB_FLUSHED generic
  sched,idle,rcu: Push rcu_idle deeper into the idle path
  cpuidle: Fixup IRQ state
  lockdep: Use raw_cpu_*() for per-cpu variables
This commit is contained in:
Linus Torvalds
2020-08-30 11:43:50 -07:00
parent 3edd8db2d5 eb1f00237a
commit b69bea8a65
19 changed files with 124 additions and 123 deletions
Download Patch File Download Diff File Expand all files Collapse all files
kernel/locking/lockdep.c
+11 -7
View File
@@ -3756,7 +3756,7 @@ void noinstr lockdep_hardirqs_on(unsigned long ip)
skip_checks:
/* we'll do an OFF -> ON transition: */
this_cpu_write(hardirqs_enabled, 1);
__this_cpu_write(hardirqs_enabled, 1);
trace->hardirq_enable_ip = ip;
trace->hardirq_enable_event = ++trace->irq_events;
debug_atomic_inc(hardirqs_on_events);
@@ -3795,7 +3795,7 @@ void noinstr lockdep_hardirqs_off(unsigned long ip)
/*
* We have done an ON -> OFF transition:
*/
this_cpu_write(hardirqs_enabled, 0);
__this_cpu_write(hardirqs_enabled, 0);
trace->hardirq_disable_ip = ip;
trace->hardirq_disable_event = ++trace->irq_events;
debug_atomic_inc(hardirqs_off_events);
@@ -4977,6 +4977,8 @@ void lock_acquire(struct lockdep_map *lock, unsigned int subclass,
{
unsigned long flags;
trace_lock_acquire(lock, subclass, trylock, read, check, nest_lock, ip);
if (unlikely(current->lockdep_recursion)) {
/* XXX allow trylock from NMI ?!? */
if (lockdep_nmi() && !trylock) {
@@ -5001,7 +5003,6 @@ void lock_acquire(struct lockdep_map *lock, unsigned int subclass,
check_flags(flags);
current->lockdep_recursion++;
trace_lock_acquire(lock, subclass, trylock, read, check, nest_lock, ip);
__lock_acquire(lock, subclass, trylock, read, check,
irqs_disabled_flags(flags), nest_lock, ip, 0, 0);
lockdep_recursion_finish();
@@ -5013,13 +5014,15 @@ void lock_release(struct lockdep_map *lock, unsigned long ip)
{
unsigned long flags;
trace_lock_release(lock, ip);
if (unlikely(current->lockdep_recursion))
return;
raw_local_irq_save(flags);
check_flags(flags);
current->lockdep_recursion++;
trace_lock_release(lock, ip);
if (__lock_release(lock, ip))
check_chain_key(current);
lockdep_recursion_finish();
@@ -5205,8 +5208,6 @@ __lock_acquired(struct lockdep_map *lock, unsigned long ip)
hlock->holdtime_stamp = now;
}
trace_lock_acquired(lock, ip);
stats = get_lock_stats(hlock_class(hlock));
if (waittime) {
if (hlock->read)
@@ -5225,6 +5226,8 @@ void lock_contended(struct lockdep_map *lock, unsigned long ip)
{
unsigned long flags;
trace_lock_acquired(lock, ip);
if (unlikely(!lock_stat || !debug_locks))
return;
@@ -5234,7 +5237,6 @@ void lock_contended(struct lockdep_map *lock, unsigned long ip)
raw_local_irq_save(flags);
check_flags(flags);
current->lockdep_recursion++;
trace_lock_contended(lock, ip);
__lock_contended(lock, ip);
lockdep_recursion_finish();
raw_local_irq_restore(flags);
@@ -5245,6 +5247,8 @@ void lock_acquired(struct lockdep_map *lock, unsigned long ip)
{
unsigned long flags;
trace_lock_contended(lock, ip);
if (unlikely(!lock_stat || !debug_locks))
return;
kernel/sched/idle.c
+12 -15
View File
@@ -54,17 +54,18 @@ __setup("hlt", cpu_idle_nopoll_setup);
static noinline int __cpuidle cpu_idle_poll(void)
{
rcu_idle_enter();
trace_cpu_idle_rcuidle(0, smp_processor_id());
local_irq_enable();
trace_cpu_idle(0, smp_processor_id());
stop_critical_timings();
rcu_idle_enter();
local_irq_enable();
while (!tif_need_resched() &&
(cpu_idle_force_poll || tick_check_broadcast_expired()))
(cpu_idle_force_poll || tick_check_broadcast_expired()))
cpu_relax();
start_critical_timings();
trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, smp_processor_id());
rcu_idle_exit();
start_critical_timings();
trace_cpu_idle(PWR_EVENT_EXIT, smp_processor_id());
return 1;
}
@@ -90,9 +91,14 @@ void __cpuidle default_idle_call(void)
if (current_clr_polling_and_test()) {
local_irq_enable();
} else {
trace_cpu_idle(1, smp_processor_id());
stop_critical_timings();
rcu_idle_enter();
arch_cpu_idle();
rcu_idle_exit();
start_critical_timings();
trace_cpu_idle(PWR_EVENT_EXIT, smp_processor_id());
}
}
@@ -158,7 +164,6 @@ static void cpuidle_idle_call(void)
if (cpuidle_not_available(drv, dev)) {
tick_nohz_idle_stop_tick();
rcu_idle_enter();
default_idle_call();
goto exit_idle;
@@ -178,21 +183,17 @@ static void cpuidle_idle_call(void)
u64 max_latency_ns;
if (idle_should_enter_s2idle()) {
rcu_idle_enter();
entered_state = call_cpuidle_s2idle(drv, dev);
if (entered_state > 0)
goto exit_idle;
rcu_idle_exit();
max_latency_ns = U64_MAX;
} else {
max_latency_ns = dev->forced_idle_latency_limit_ns;
}
tick_nohz_idle_stop_tick();
rcu_idle_enter();
next_state = cpuidle_find_deepest_state(drv, dev, max_latency_ns);
call_cpuidle(drv, dev, next_state);
@@ -209,8 +210,6 @@ static void cpuidle_idle_call(void)
else
tick_nohz_idle_retain_tick();
rcu_idle_enter();
entered_state = call_cpuidle(drv, dev, next_state);
/*
* Give the governor an opportunity to reflect on the outcome
@@ -226,8 +225,6 @@ exit_idle:
*/
if (WARN_ON_ONCE(irqs_disabled()))
local_irq_enable();
rcu_idle_exit();
}
/*