4.19-stable patches

added patches:
	sched-idle-rcu-push-rcu_idle-deeper-into-the-idle-path.patch

diff --git a/queue-4.19/sched-idle-rcu-push-rcu_idle-deeper-into-the-idle-path.patch b/queue-4.19/sched-idle-rcu-push-rcu_idle-deeper-into-the-idle-path.patch
new file mode 100644 (file)
index 0000000..7bee06e
--- /dev/null
+++ b/queue-4.19/sched-idle-rcu-push-rcu_idle-deeper-into-the-idle-path.patch
@@ -0,0 +1,164 @@
+From 1098582a0f6c4e8fd28da0a6305f9233d02c9c1d Mon Sep 17 00:00:00 2001
+From: Peter Zijlstra <peterz@infradead.org>
+Date: Fri, 7 Aug 2020 20:50:19 +0200
+Subject: sched,idle,rcu: Push rcu_idle deeper into the idle path
+
+From: Peter Zijlstra <peterz@infradead.org>
+
+commit 1098582a0f6c4e8fd28da0a6305f9233d02c9c1d upstream.
+
+Lots of things take locks, due to a wee bug, rcu_lockdep didn't notice
+that the locking tracepoints were using RCU.
+
+Push rcu_idle_{enter,exit}() as deep as possible into the idle paths,
+this also resolves a lot of _rcuidle()/RCU_NONIDLE() usage.
+
+Specifically, sched_clock_idle_wakeup_event() will use ktime which
+will use seqlocks which will tickle lockdep, and
+stop_critical_timings() uses lock.
+
+Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
+Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
+Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
+Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
+Tested-by: Marco Elver <elver@google.com>
+Link: https://lkml.kernel.org/r/20200821085348.310943801@infradead.org
+Tested-by: Linux Kernel Functional Testing <lkft@linaro.org>
+Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ drivers/cpuidle/cpuidle.c |   12 ++++++++----
+ kernel/sched/idle.c       |   22 ++++++++--------------
+ 2 files changed, 16 insertions(+), 18 deletions(-)
+
+--- a/drivers/cpuidle/cpuidle.c
++++ b/drivers/cpuidle/cpuidle.c
+@@ -140,13 +140,14 @@ static void enter_s2idle_proper(struct c
+        * executing it contains RCU usage regarded as invalid in the idle
+        * context, so tell RCU about that.
+        */
+-      RCU_NONIDLE(tick_freeze());
++      tick_freeze();
+       /*
+        * The state used here cannot be a "coupled" one, because the "coupled"
+        * cpuidle mechanism enables interrupts and doing that with timekeeping
+        * suspended is generally unsafe.
+        */
+       stop_critical_timings();
++      rcu_idle_enter();
+       drv->states[index].enter_s2idle(dev, drv, index);
+       if (WARN_ON_ONCE(!irqs_disabled()))
+               local_irq_disable();
+@@ -155,7 +156,8 @@ static void enter_s2idle_proper(struct c
+        * first CPU executing it calls functions containing RCU read-side
+        * critical sections, so tell RCU about that.
+        */
+-      RCU_NONIDLE(tick_unfreeze());
++      rcu_idle_exit();
++      tick_unfreeze();
+       start_critical_timings();
+ 
+       time_end = ns_to_ktime(local_clock());
+@@ -224,16 +226,18 @@ int cpuidle_enter_state(struct cpuidle_d
+       /* Take note of the planned idle state. */
+       sched_idle_set_state(target_state);
+ 
+-      trace_cpu_idle_rcuidle(index, dev->cpu);
++      trace_cpu_idle(index, dev->cpu);
+       time_start = ns_to_ktime(local_clock());
+ 
+       stop_critical_timings();
++      rcu_idle_enter();
+       entered_state = target_state->enter(dev, drv, index);
++      rcu_idle_exit();
+       start_critical_timings();
+ 
+       sched_clock_idle_wakeup_event();
+       time_end = ns_to_ktime(local_clock());
+-      trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, dev->cpu);
++      trace_cpu_idle(PWR_EVENT_EXIT, dev->cpu);
+ 
+       /* The cpu is no longer idle or about to enter idle. */
+       sched_idle_set_state(NULL);
+--- a/kernel/sched/idle.c
++++ b/kernel/sched/idle.c
+@@ -53,17 +53,18 @@ __setup("hlt", cpu_idle_nopoll_setup);
+ 
+ static noinline int __cpuidle cpu_idle_poll(void)
+ {
++      trace_cpu_idle(0, smp_processor_id());
++      stop_critical_timings();
+       rcu_idle_enter();
+-      trace_cpu_idle_rcuidle(0, smp_processor_id());
+       local_irq_enable();
+-      stop_critical_timings();
+ 
+       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;
+ }
+@@ -90,7 +91,9 @@ void __cpuidle default_idle_call(void)
+               local_irq_enable();
+       } else {
+               stop_critical_timings();
++              rcu_idle_enter();
+               arch_cpu_idle();
++              rcu_idle_exit();
+               start_critical_timings();
+       }
+ }
+@@ -148,7 +151,6 @@ 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;
+@@ -166,19 +168,15 @@ static void cpuidle_idle_call(void)
+ 
+       if (idle_should_enter_s2idle() || dev->use_deepest_state) {
+               if (idle_should_enter_s2idle()) {
+-                      rcu_idle_enter();
+ 
+                       entered_state = cpuidle_enter_s2idle(drv, dev);
+                       if (entered_state > 0) {
+                               local_irq_enable();
+                               goto exit_idle;
+                       }
+-
+-                      rcu_idle_exit();
+               }
+ 
+               tick_nohz_idle_stop_tick();
+-              rcu_idle_enter();
+ 
+               next_state = cpuidle_find_deepest_state(drv, dev);
+               call_cpuidle(drv, dev, next_state);
+@@ -195,8 +193,6 @@ 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
+@@ -212,8 +208,6 @@ exit_idle:
+        */
+       if (WARN_ON_ONCE(irqs_disabled()))
+               local_irq_enable();
+-
+-      rcu_idle_exit();
+ }
+ 
+ /*

diff --git a/queue-4.19/series b/queue-4.19/series
index 94d356646727f8b163257a0f50bcafa874aed40f..0d1a6443a2e4f2595685e70342ab2b60c978a4c2 100644 (file)
--- a/queue-4.19/series
+++ b/queue-4.19/series
@@ -18,3 +18,4 @@ net-nfc-fix-races-in-nfc_llcp_sock_get-and-nfc_llcp_.patch
 nfc-nci-assert-requested-protocol-is-valid.patch
 workqueue-override-implicit-ordered-attribute-in-wor.patch
 perf-inject-fix-gen_elf_text_offset-for-jit.patch
+sched-idle-rcu-push-rcu_idle-deeper-into-the-idle-path.patch