diff options
| -rw-r--r-- | include/linux/stop_machine.h | 34 | ||||
| -rw-r--r-- | kernel/cpu.c | 3 | ||||
| -rw-r--r-- | kernel/stop_machine.c | 27 |
3 files changed, 39 insertions, 25 deletions
diff --git a/include/linux/stop_machine.h b/include/linux/stop_machine.h index 36c2c72..f1cb0ba 100644 --- a/include/linux/stop_machine.h +++ b/include/linux/stop_machine.h @@ -5,19 +5,19 @@ (and more). So the "read" side to such a lock is anything which diables preeempt. */ #include <linux/cpu.h> +#include <linux/cpumask.h> #include <asm/system.h> #if defined(CONFIG_STOP_MACHINE) && defined(CONFIG_SMP) +/* Deprecated, but useful for transition. */ #define ALL_CPUS ~0U /** - * stop_machine_run: freeze the machine on all CPUs and run this function + * stop_machine: freeze the machine on all CPUs and run this function * @fn: the function to run * @data: the data ptr for the @fn() - * @cpu: if @cpu == n, run @fn() on cpu n - * if @cpu == NR_CPUS, run @fn() on any cpu - * if @cpu == ALL_CPUS, run @fn() on every online CPU. + * @cpus: the cpus to run the @fn() on (NULL = any online cpu) * * Description: This causes a thread to be scheduled on every cpu, * each of which disables interrupts. The result is that noone is @@ -26,22 +26,22 @@ * * This can be thought of as a very heavy write lock, equivalent to * grabbing every spinlock in the kernel. */ -int stop_machine_run(int (*fn)(void *), void *data, unsigned int cpu); +int stop_machine(int (*fn)(void *), void *data, const cpumask_t *cpus); /** - * __stop_machine_run: freeze the machine on all CPUs and run this function + * __stop_machine: freeze the machine on all CPUs and run this function * @fn: the function to run * @data: the data ptr for the @fn - * @cpu: the cpu to run @fn on (or any, if @cpu == NR_CPUS. + * @cpus: the cpus to run the @fn() on (NULL = any online cpu) * * Description: This is a special version of the above, which assumes cpus * won't come or go while it's being called. Used by hotplug cpu. */ -int __stop_machine_run(int (*fn)(void *), void *data, unsigned int cpu); +int __stop_machine(int (*fn)(void *), void *data, const cpumask_t *cpus); #else -static inline int stop_machine_run(int (*fn)(void *), void *data, - unsigned int cpu) +static inline int stop_machine(int (*fn)(void *), void *data, + const cpumask_t *cpus) { int ret; local_irq_disable(); @@ -50,4 +50,18 @@ static inline int stop_machine_run(int (*fn)(void *), void *data, return ret; } #endif /* CONFIG_SMP */ + +static inline int __deprecated stop_machine_run(int (*fn)(void *), void *data, + unsigned int cpu) +{ + /* If they don't care which cpu fn runs on, just pick one. */ + if (cpu == NR_CPUS) + return stop_machine(fn, data, NULL); + else if (cpu == ~0U) + return stop_machine(fn, data, &cpu_possible_map); + else { + cpumask_t cpus = cpumask_of_cpu(cpu); + return stop_machine(fn, data, &cpus); + } +} #endif /* _LINUX_STOP_MACHINE */ diff --git a/kernel/cpu.c b/kernel/cpu.c index 53cf508..29510d68 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -248,8 +248,9 @@ static int __ref _cpu_down(unsigned int cpu, int tasks_frozen) cpus_setall(tmp); cpu_clear(cpu, tmp); set_cpus_allowed_ptr(current, &tmp); + tmp = cpumask_of_cpu(cpu); - err = __stop_machine_run(take_cpu_down, &tcd_param, cpu); + err = __stop_machine(take_cpu_down, &tcd_param, &tmp); if (err) { /* CPU didn't die: tell everyone. Can't complain. */ if (raw_notifier_call_chain(&cpu_chain, CPU_DOWN_FAILED | mod, diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c index 35882dc..e446c7c 100644 --- a/kernel/stop_machine.c +++ b/kernel/stop_machine.c @@ -100,7 +100,7 @@ static int chill(void *unused) return 0; } -int __stop_machine_run(int (*fn)(void *), void *data, unsigned int cpu) +int __stop_machine(int (*fn)(void *), void *data, const cpumask_t *cpus) { int i, err; struct stop_machine_data active, idle; @@ -112,10 +112,6 @@ int __stop_machine_run(int (*fn)(void *), void *data, unsigned int cpu) idle.fn = chill; idle.data = NULL; - /* If they don't care which cpu fn runs on, just pick one. */ - if (cpu == NR_CPUS) - cpu = any_online_cpu(cpu_online_map); - /* This could be too big for stack on large machines. */ threads = kcalloc(NR_CPUS, sizeof(threads[0]), GFP_KERNEL); if (!threads) @@ -128,13 +124,16 @@ int __stop_machine_run(int (*fn)(void *), void *data, unsigned int cpu) set_state(STOPMACHINE_PREPARE); for_each_online_cpu(i) { - struct stop_machine_data *smdata; + struct stop_machine_data *smdata = &idle; struct sched_param param = { .sched_priority = MAX_RT_PRIO-1 }; - if (cpu == ALL_CPUS || i == cpu) - smdata = &active; - else - smdata = &idle; + if (!cpus) { + if (i == first_cpu(cpu_online_map)) + smdata = &active; + } else { + if (cpu_isset(i, *cpus)) + smdata = &active; + } threads[i] = kthread_create((void *)stop_cpu, smdata, "kstop%u", i); @@ -154,7 +153,7 @@ int __stop_machine_run(int (*fn)(void *), void *data, unsigned int cpu) /* We've created all the threads. Wake them all: hold this CPU so one * doesn't hit this CPU until we're ready. */ - cpu = get_cpu(); + get_cpu(); for_each_online_cpu(i) wake_up_process(threads[i]); @@ -177,15 +176,15 @@ kill_threads: return err; } -int stop_machine_run(int (*fn)(void *), void *data, unsigned int cpu) +int stop_machine(int (*fn)(void *), void *data, const cpumask_t *cpus) { int ret; /* No CPUs can come up or down during this. */ get_online_cpus(); - ret = __stop_machine_run(fn, data, cpu); + ret = __stop_machine(fn, data, cpus); put_online_cpus(); return ret; } -EXPORT_SYMBOL_GPL(stop_machine_run); +EXPORT_SYMBOL_GPL(stop_machine); |
