redonkable/alistair23-linux
redonkable/alistair23-linux
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Merge branch 'core-ipi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

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* 'core-ipi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  generic-ipi: Add smp_call_function_any()
  generic-ipi: Fix misleading smp_call_function*() description
This commit is contained in:
Linus Torvalds 2009-12-05 09:49:46 -08:00
parent 7b626acb8f 2ea6dec4a2
commit 9b269d4034
2 changed files with 58 additions and 9 deletions
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11
include/linux/smp.h
View file

@ -76,6 +76,9 @@ void smp_call_function_many(const struct cpumask *mask,
void __smp_call_function_single(int cpuid, struct call_single_data *data,
int wait);
int smp_call_function_any(const struct cpumask *mask,
void (*func)(void *info), void *info, int wait);
/*
* Generic and arch helpers
*/
@ -137,9 +140,15 @@ static inline void smp_send_reschedule(int cpu) { }
#define smp_prepare_boot_cpu() do {} while (0)
#define smp_call_function_many(mask, func, info, wait) \
(up_smp_call_function(func, info))
static inline void init_call_single_data(void)
static inline void init_call_single_data(void) { }
static inline int
smp_call_function_any(const struct cpumask *mask, void (*func)(void *info),
void *info, int wait)
{
return smp_call_function_single(0, func, info, wait);
}
#endif /* !SMP */
/*

56
kernel/smp.c
View file

@ -265,9 +265,7 @@ static DEFINE_PER_CPU(struct call_single_data, csd_data);
* @info: An arbitrary pointer to pass to the function.
* @wait: If true, wait until function has completed on other CPUs.
*
* Returns 0 on success, else a negative status code. Note that @wait
* will be implicitly turned on in case of allocation failures, since
* we fall back to on-stack allocation.
* Returns 0 on success, else a negative status code.
*/
int smp_call_function_single(int cpu, void (*func) (void *info), void *info,
int wait)
@ -321,6 +319,51 @@ int smp_call_function_single(int cpu, void (*func) (void *info), void *info,
}
EXPORT_SYMBOL(smp_call_function_single);
/*
* smp_call_function_any - Run a function on any of the given cpus
* @mask: The mask of cpus it can run on.
* @func: The function to run. This must be fast and non-blocking.
* @info: An arbitrary pointer to pass to the function.
* @wait: If true, wait until function has completed.
*
* Returns 0 on success, else a negative status code (if no cpus were online).
* Note that @wait will be implicitly turned on in case of allocation failures,
* since we fall back to on-stack allocation.
*
* Selection preference:
* 1) current cpu if in @mask
* 2) any cpu of current node if in @mask
* 3) any other online cpu in @mask
*/
int smp_call_function_any(const struct cpumask *mask,
void (*func)(void *info), void *info, int wait)
{
unsigned int cpu;
const struct cpumask *nodemask;
int ret;
/* Try for same CPU (cheapest) */
cpu = get_cpu();
if (cpumask_test_cpu(cpu, mask))
goto call;
/* Try for same node. */
nodemask = cpumask_of_node(cpu);
for (cpu = cpumask_first_and(nodemask, mask); cpu < nr_cpu_ids;
cpu = cpumask_next_and(cpu, nodemask, mask)) {
if (cpu_online(cpu))
goto call;
}
/* Any online will do: smp_call_function_single handles nr_cpu_ids. */
cpu = cpumask_any_and(mask, cpu_online_mask);
call:
ret = smp_call_function_single(cpu, func, info, wait);
put_cpu();
return ret;
}
EXPORT_SYMBOL_GPL(smp_call_function_any);
/**
* __smp_call_function_single(): Run a function on another CPU
* @cpu: The CPU to run on.
@ -355,9 +398,7 @@ void __smp_call_function_single(int cpu, struct call_single_data *data,
* @wait: If true, wait (atomically) until function has completed
* on other CPUs.
*
* If @wait is true, then returns once @func has returned. Note that @wait
* will be implicitly turned on in case of allocation failures, since
* we fall back to on-stack allocation.
* If @wait is true, then returns once @func has returned.
*
* You must not call this function with disabled interrupts or from a
* hardware interrupt handler or from a bottom half handler. Preemption
@ -443,8 +484,7 @@ EXPORT_SYMBOL(smp_call_function_many);
* Returns 0.
*
* If @wait is true, then returns once @func has returned; otherwise
* it returns just before the target cpu calls @func. In case of allocation
* failure, @wait will be implicitly turned on.
* it returns just before the target cpu calls @func.
*
* You must not call this function with disabled interrupts or from a
* hardware interrupt handler or from a bottom half handler.