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| author | Paul E. McKenney <paulmck@kernel.org> | 2021-07-28 16:04:35 -0700 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@kernel.org> | 2021-08-25 11:45:59 -0700 |
| commit | 545fb85f707c973cc4f1718572e33267c9c110a2 (patch) | |
| tree | 23be9f3beb1827c1c03f8edafeb29599c97b8742 | |
| parent | 652af0f9f927ead578fa9cdb4c87b121bbbc050c (diff) | |
| download | linux-rcu-545fb85f707c973cc4f1718572e33267c9c110a2.tar.gz | |
EXP cpu: Make cpu_hp_check_delay() return true when detecting an anomaly
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
| -rw-r--r-- | include/linux/cpu.h | 4 | ||||
| -rw-r--r-- | kernel/cpu.c | 17 |
2 files changed, 14 insertions, 7 deletions
diff --git a/include/linux/cpu.h b/include/linux/cpu.h index 2cdd1afd03504..93b9a28ea2bcd 100644 --- a/include/linux/cpu.h +++ b/include/linux/cpu.h @@ -130,7 +130,7 @@ int cpu_device_down(struct device *dev); extern void smp_shutdown_nonboot_cpus(unsigned int primary_cpu); extern void cpu_hp_start_now(void); extern void cpu_hp_stop_now(void); -extern void cpu_hp_check_delay(const char *s, const void *func); +extern bool cpu_hp_check_delay(const char *s, const void *func); #else /* CONFIG_HOTPLUG_CPU */ @@ -146,7 +146,7 @@ static inline int remove_cpu(unsigned int cpu) { return -EPERM; } static inline void smp_shutdown_nonboot_cpus(unsigned int primary_cpu) { } static inline void cpu_hp_start_now(void) { } static inline void cpu_hp_stop_now(void) { } -static inline void cpu_hp_check_delay(const char *s, void *func) { } +static inline bool cpu_hp_check_delay(const char *s, void *func) { return false; } #endif /* !CONFIG_HOTPLUG_CPU */ /* Wrappers which go away once all code is converted */ diff --git a/kernel/cpu.c b/kernel/cpu.c index b0112cd976e3e..6ae1c7544d5b4 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -154,21 +154,28 @@ void cpu_hp_stop_now(void) smp_store_release(&cpu_hp_start_time_valid, false); } -void cpu_hp_check_delay(const char *s, const void *func) +/* Return true if a time-delay anomaly was detected. */ +bool cpu_hp_check_delay(const char *s, const void *func) { + bool ret = false; u64 t, t1; if (!smp_load_acquire(&cpu_hp_start_time_valid)) - return; + return false; t = READ_ONCE(cpu_hp_start_time); smp_mb(); if (!READ_ONCE(cpu_hp_start_time_valid)) - return; + return false; t1 = ktime_get(); - if (WARN_ONCE(time_after64(t1, t + 100 * NSEC_PER_SEC), "%s %ps took %llu milliseconds\n", s, func, (t1 - t) / NSEC_PER_MSEC)) + if (WARN_ONCE(time_after64(t1, t + 100 * NSEC_PER_SEC), "%s %ps took %llu milliseconds\n", s, func, (t1 - t) / NSEC_PER_MSEC)) { WRITE_ONCE(cpu_hp_start_time, t1); - if (WARN_ONCE(time_before64(t1, t - 25 * NSEC_PER_MSEC), "%s %ps clock went backwards %llu milliseconds\n", s, func, (t - t1) / NSEC_PER_MSEC)) + ret = true; + } + if (WARN_ONCE(time_before64(t1, t - 25 * NSEC_PER_MSEC), "%s %ps clock went backwards %llu milliseconds\n", s, func, (t - t1) / NSEC_PER_MSEC)){ WRITE_ONCE(cpu_hp_start_time, t1); + ret = true; + } + return ret; } #endif /* #ifdef CONFIG_SMP */ |