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author | Linus Torvalds <torvalds@linux-foundation.org> | 2014-10-09 06:30:57 -0400 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-10-09 06:30:57 -0400 |
commit | afa3536be88b435a057cb727b48fd3d760a497d2 (patch) | |
tree | 8562d3c8327286746ae835ef8eb39d4494a1054d /kernel/time | |
parent | 35a9ad8af0bb0fa3525e6d0d20e32551d226f38e (diff) | |
parent | 9b01f5bf3999a3db5b1bbd9fdfd80d8d304e94ee (diff) | |
download | op-kernel-dev-afa3536be88b435a057cb727b48fd3d760a497d2.zip op-kernel-dev-afa3536be88b435a057cb727b48fd3d760a497d2.tar.gz |
Merge branch 'timers-nohz-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer fixes from Ingo Molnar:
"Main changes:
- Fix the deadlock reported by Dave Jones et al
- Clean up and fix nohz_full interaction with arch abilities
- nohz init code consolidation/cleanup"
* 'timers-nohz-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
nohz: nohz full depends on irq work self IPI support
nohz: Consolidate nohz full init code
arm64: Tell irq work about self IPI support
arm: Tell irq work about self IPI support
x86: Tell irq work about self IPI support
irq_work: Force raised irq work to run on irq work interrupt
irq_work: Introduce arch_irq_work_has_interrupt()
nohz: Move nohz full init call to tick init
Diffstat (limited to 'kernel/time')
-rw-r--r-- | kernel/time/tick-common.c | 1 | ||||
-rw-r--r-- | kernel/time/tick-internal.h | 7 | ||||
-rw-r--r-- | kernel/time/tick-sched.c | 52 | ||||
-rw-r--r-- | kernel/time/timer.c | 2 |
4 files changed, 42 insertions, 20 deletions
diff --git a/kernel/time/tick-common.c b/kernel/time/tick-common.c index 0a0608e..052b4b5 100644 --- a/kernel/time/tick-common.c +++ b/kernel/time/tick-common.c @@ -400,4 +400,5 @@ void tick_resume(void) void __init tick_init(void) { tick_broadcast_init(); + tick_nohz_init(); } diff --git a/kernel/time/tick-internal.h b/kernel/time/tick-internal.h index c19c1d8..366aeb4 100644 --- a/kernel/time/tick-internal.h +++ b/kernel/time/tick-internal.h @@ -99,6 +99,13 @@ static inline int tick_broadcast_oneshot_active(void) { return 0; } static inline bool tick_broadcast_oneshot_available(void) { return false; } #endif /* !TICK_ONESHOT */ +/* NO_HZ_FULL internal */ +#ifdef CONFIG_NO_HZ_FULL +extern void tick_nohz_init(void); +# else +static inline void tick_nohz_init(void) { } +#endif + /* * Broadcasting support */ diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index f654a8a..5a9ff24 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -295,22 +295,12 @@ out: /* Parse the boot-time nohz CPU list from the kernel parameters. */ static int __init tick_nohz_full_setup(char *str) { - int cpu; - alloc_bootmem_cpumask_var(&tick_nohz_full_mask); - alloc_bootmem_cpumask_var(&housekeeping_mask); if (cpulist_parse(str, tick_nohz_full_mask) < 0) { pr_warning("NOHZ: Incorrect nohz_full cpumask\n"); + free_bootmem_cpumask_var(tick_nohz_full_mask); return 1; } - - cpu = smp_processor_id(); - if (cpumask_test_cpu(cpu, tick_nohz_full_mask)) { - pr_warning("NO_HZ: Clearing %d from nohz_full range for timekeeping\n", cpu); - cpumask_clear_cpu(cpu, tick_nohz_full_mask); - } - cpumask_andnot(housekeeping_mask, - cpu_possible_mask, tick_nohz_full_mask); tick_nohz_full_running = true; return 1; @@ -349,18 +339,11 @@ static int tick_nohz_init_all(void) #ifdef CONFIG_NO_HZ_FULL_ALL if (!alloc_cpumask_var(&tick_nohz_full_mask, GFP_KERNEL)) { - pr_err("NO_HZ: Can't allocate full dynticks cpumask\n"); - return err; - } - if (!alloc_cpumask_var(&housekeeping_mask, GFP_KERNEL)) { - pr_err("NO_HZ: Can't allocate not-full dynticks cpumask\n"); + WARN(1, "NO_HZ: Can't allocate full dynticks cpumask\n"); return err; } err = 0; cpumask_setall(tick_nohz_full_mask); - cpumask_clear_cpu(smp_processor_id(), tick_nohz_full_mask); - cpumask_clear(housekeeping_mask); - cpumask_set_cpu(smp_processor_id(), housekeeping_mask); tick_nohz_full_running = true; #endif return err; @@ -375,6 +358,37 @@ void __init tick_nohz_init(void) return; } + if (!alloc_cpumask_var(&housekeeping_mask, GFP_KERNEL)) { + WARN(1, "NO_HZ: Can't allocate not-full dynticks cpumask\n"); + cpumask_clear(tick_nohz_full_mask); + tick_nohz_full_running = false; + return; + } + + /* + * Full dynticks uses irq work to drive the tick rescheduling on safe + * locking contexts. But then we need irq work to raise its own + * interrupts to avoid circular dependency on the tick + */ + if (!arch_irq_work_has_interrupt()) { + pr_warning("NO_HZ: Can't run full dynticks because arch doesn't " + "support irq work self-IPIs\n"); + cpumask_clear(tick_nohz_full_mask); + cpumask_copy(housekeeping_mask, cpu_possible_mask); + tick_nohz_full_running = false; + return; + } + + cpu = smp_processor_id(); + + if (cpumask_test_cpu(cpu, tick_nohz_full_mask)) { + pr_warning("NO_HZ: Clearing %d from nohz_full range for timekeeping\n", cpu); + cpumask_clear_cpu(cpu, tick_nohz_full_mask); + } + + cpumask_andnot(housekeeping_mask, + cpu_possible_mask, tick_nohz_full_mask); + for_each_cpu(cpu, tick_nohz_full_mask) context_tracking_cpu_set(cpu); diff --git a/kernel/time/timer.c b/kernel/time/timer.c index aca5dfe..9bbb834 100644 --- a/kernel/time/timer.c +++ b/kernel/time/timer.c @@ -1385,7 +1385,7 @@ void update_process_times(int user_tick) rcu_check_callbacks(cpu, user_tick); #ifdef CONFIG_IRQ_WORK if (in_irq()) - irq_work_run(); + irq_work_tick(); #endif scheduler_tick(); run_posix_cpu_timers(p); |