diff options
author | Sebastian Andrzej Siewior <bigeasy@linutronix.de> | 2015-04-10 11:50:22 +0200 |
---|---|---|
committer | Anders Roxell <anders.roxell@linaro.org> | 2015-06-01 12:03:39 +0200 |
commit | 0545bb2edf4c723d64c106b8bcac7a965deec53b (patch) | |
tree | efea82f7ce2a990b72cac7b17a689cf63714e85a | |
parent | 873c6bc22569e32fa14f6310599f9a42d172c1a7 (diff) |
kernel/irq_work: fix no_hz deadlock
Invoking NO_HZ's irq_work callback from timer irq is not working very
well if the callback decides to invoke hrtimer_cancel():
|hrtimer_try_to_cancel+0x55/0x5f
|hrtimer_cancel+0x16/0x28
|tick_nohz_restart+0x17/0x72
|__tick_nohz_full_check+0x8e/0x93
|nohz_full_kick_work_func+0xe/0x10
|irq_work_run_list+0x39/0x57
|irq_work_tick+0x60/0x67
|update_process_times+0x57/0x67
|tick_sched_handle+0x4a/0x59
|tick_sched_timer+0x3b/0x64
|__run_hrtimer+0x7a/0x149
|hrtimer_interrupt+0x1cc/0x2c5
and here we deadlock while waiting for the lock which we are holding.
To fix this I'm doing the same thing that upstream is doing: is the
irq_work dedicated IRQ and use it only for what is marked as "hirq"
which should only be the FULL_NO_HZ related work.
Cc: stable-rt@vger.kernel.org
Reported-by: Carsten Emde <C.Emde@osadl.org>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
[ Added back in_irq() check for non PREEMPT_RT configs ]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
-rw-r--r-- | arch/arm/kernel/smp.c | 2 | ||||
-rw-r--r-- | arch/powerpc/kernel/time.c | 2 | ||||
-rw-r--r-- | arch/sparc/kernel/pcr.c | 2 | ||||
-rw-r--r-- | arch/x86/kernel/irq_work.c | 2 | ||||
-rw-r--r-- | kernel/irq_work.c | 5 | ||||
-rw-r--r-- | kernel/time/tick-sched.c | 5 | ||||
-rw-r--r-- | kernel/timer.c | 2 |
7 files changed, 8 insertions, 12 deletions
diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c index 686f1d1eb32e..8cd3724714fe 100644 --- a/arch/arm/kernel/smp.c +++ b/arch/arm/kernel/smp.c @@ -463,14 +463,12 @@ void arch_send_call_function_single_ipi(int cpu) } #ifdef CONFIG_IRQ_WORK -#ifndef CONFIG_PREEMPT_RT_FULL void arch_irq_work_raise(void) { if (is_smp()) smp_cross_call(cpumask_of(smp_processor_id()), IPI_IRQ_WORK); } #endif -#endif static const char *ipi_types[NR_IPI] = { #define S(x,s) [x] = s diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c index 6d37d7603a8f..5bec5fd82a7e 100644 --- a/arch/powerpc/kernel/time.c +++ b/arch/powerpc/kernel/time.c @@ -423,7 +423,7 @@ unsigned long profile_pc(struct pt_regs *regs) EXPORT_SYMBOL(profile_pc); #endif -#if defined(CONFIG_IRQ_WORK) && !defined(CONFIG_PREEMPT_RT_FULL) +#if defined(CONFIG_IRQ_WORK) /* * 64-bit uses a byte in the PACA, 32-bit uses a per-cpu variable... diff --git a/arch/sparc/kernel/pcr.c b/arch/sparc/kernel/pcr.c index 927d9c5e50f5..7e967c8018c8 100644 --- a/arch/sparc/kernel/pcr.c +++ b/arch/sparc/kernel/pcr.c @@ -43,12 +43,10 @@ void __irq_entry deferred_pcr_work_irq(int irq, struct pt_regs *regs) set_irq_regs(old_regs); } -#ifndef CONFIG_PREEMPT_RT_FULL void arch_irq_work_raise(void) { set_softint(1 << PIL_DEFERRED_PCR_WORK); } -#endif const struct pcr_ops *pcr_ops; EXPORT_SYMBOL_GPL(pcr_ops); diff --git a/arch/x86/kernel/irq_work.c b/arch/x86/kernel/irq_work.c index 3d21f7bd7b42..1de84e3ab4e0 100644 --- a/arch/x86/kernel/irq_work.c +++ b/arch/x86/kernel/irq_work.c @@ -38,7 +38,6 @@ __visible void smp_trace_irq_work_interrupt(struct pt_regs *regs) exiting_irq(); } -#ifndef CONFIG_PREEMPT_RT_FULL void arch_irq_work_raise(void) { #ifdef CONFIG_X86_LOCAL_APIC @@ -49,4 +48,3 @@ void arch_irq_work_raise(void) apic_wait_icr_idle(); #endif } -#endif diff --git a/kernel/irq_work.c b/kernel/irq_work.c index 35d21f93bbe8..5f7d93d89c7f 100644 --- a/kernel/irq_work.c +++ b/kernel/irq_work.c @@ -16,6 +16,7 @@ #include <linux/tick.h> #include <linux/cpu.h> #include <linux/notifier.h> +#include <linux/interrupt.h> #include <asm/processor.h> @@ -51,11 +52,7 @@ static bool irq_work_claim(struct irq_work *work) return true; } -#ifdef CONFIG_PREEMPT_RT_FULL -void arch_irq_work_raise(void) -#else void __weak arch_irq_work_raise(void) -#endif { /* * Lame architectures will get the timer tick callback diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index ab32130964b6..6c97081f67f9 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -180,6 +180,11 @@ static bool can_stop_full_tick(void) return false; } + if (!arch_irq_work_has_interrupt()) { + trace_tick_stop(0, "missing irq work interrupt\n"); + return false; + } + /* sched_clock_tick() needs us? */ #ifdef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK /* diff --git a/kernel/timer.c b/kernel/timer.c index 34fd2dbba3e3..36b9f10bb3c7 100644 --- a/kernel/timer.c +++ b/kernel/timer.c @@ -1450,7 +1450,7 @@ void update_process_times(int user_tick) scheduler_tick(); run_local_timers(); rcu_check_callbacks(cpu, user_tick); -#if defined(CONFIG_IRQ_WORK) +#if defined(CONFIG_IRQ_WORK) && !defined(CONFIG_PREEMPT_RT_FULL) if (in_irq()) irq_work_run(); #endif |