A small set of SMP core code changes:

- Rework the smp function call core code to avoid the allocation of an
    additional cpumask.
 
  - Remove the not longer required GFP argument from on_each_cpu_cond() and
    on_each_cpu_cond_mask() and fixup the callers.
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Merge tag 'smp-core-2020-01-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull core SMP updates from Thomas Gleixner:
 "A small set of SMP core code changes:

   - Rework the smp function call core code to avoid the allocation of
     an additional cpumask

   - Remove the not longer required GFP argument from on_each_cpu_cond()
     and on_each_cpu_cond_mask() and fixup the callers"

* tag 'smp-core-2020-01-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  smp: Remove allocation mask from on_each_cpu_cond.*()
  smp: Add a smp_cond_func_t argument to smp_call_function_many()
  smp: Use smp_cond_func_t as type for the conditional function
This commit is contained in:
Linus Torvalds 2020-01-27 17:04:51 -08:00
commit ab67f60025
6 changed files with 54 additions and 70 deletions

View File

@ -708,7 +708,7 @@ void native_flush_tlb_others(const struct cpumask *cpumask,
(void *)info, 1);
else
on_each_cpu_cond_mask(tlb_is_not_lazy, flush_tlb_func_remote,
(void *)info, 1, GFP_ATOMIC, cpumask);
(void *)info, 1, cpumask);
}
/*

View File

@ -1433,7 +1433,7 @@ static bool has_bh_in_lru(int cpu, void *dummy)
void invalidate_bh_lrus(void)
{
on_each_cpu_cond(has_bh_in_lru, invalidate_bh_lru, NULL, 1, GFP_KERNEL);
on_each_cpu_cond(has_bh_in_lru, invalidate_bh_lru, NULL, 1);
}
EXPORT_SYMBOL_GPL(invalidate_bh_lrus);

View File

@ -15,6 +15,7 @@
#include <linux/llist.h>
typedef void (*smp_call_func_t)(void *info);
typedef bool (*smp_cond_func_t)(int cpu, void *info);
struct __call_single_data {
struct llist_node llist;
smp_call_func_t func;
@ -49,13 +50,11 @@ void on_each_cpu_mask(const struct cpumask *mask, smp_call_func_t func,
* cond_func returns a positive value. This may include the local
* processor.
*/
void on_each_cpu_cond(bool (*cond_func)(int cpu, void *info),
smp_call_func_t func, void *info, bool wait,
gfp_t gfp_flags);
void on_each_cpu_cond(smp_cond_func_t cond_func, smp_call_func_t func,
void *info, bool wait);
void on_each_cpu_cond_mask(bool (*cond_func)(int cpu, void *info),
smp_call_func_t func, void *info, bool wait,
gfp_t gfp_flags, const struct cpumask *mask);
void on_each_cpu_cond_mask(smp_cond_func_t cond_func, smp_call_func_t func,
void *info, bool wait, const struct cpumask *mask);
int smp_call_function_single_async(int cpu, call_single_data_t *csd);

View File

@ -395,22 +395,9 @@ int smp_call_function_any(const struct cpumask *mask,
}
EXPORT_SYMBOL_GPL(smp_call_function_any);
/**
* smp_call_function_many(): Run a function on a set of other CPUs.
* @mask: The set of cpus to run on (only runs on online subset).
* @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 (atomically) until function has completed
* on other CPUs.
*
* 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
* must be disabled when calling this function.
*/
void smp_call_function_many(const struct cpumask *mask,
smp_call_func_t func, void *info, bool wait)
static void smp_call_function_many_cond(const struct cpumask *mask,
smp_call_func_t func, void *info,
bool wait, smp_cond_func_t cond_func)
{
struct call_function_data *cfd;
int cpu, next_cpu, this_cpu = smp_processor_id();
@ -448,7 +435,8 @@ void smp_call_function_many(const struct cpumask *mask,
/* Fastpath: do that cpu by itself. */
if (next_cpu >= nr_cpu_ids) {
smp_call_function_single(cpu, func, info, wait);
if (!cond_func || (cond_func && cond_func(cpu, info)))
smp_call_function_single(cpu, func, info, wait);
return;
}
@ -465,6 +453,9 @@ void smp_call_function_many(const struct cpumask *mask,
for_each_cpu(cpu, cfd->cpumask) {
call_single_data_t *csd = per_cpu_ptr(cfd->csd, cpu);
if (cond_func && !cond_func(cpu, info))
continue;
csd_lock(csd);
if (wait)
csd->flags |= CSD_FLAG_SYNCHRONOUS;
@ -486,6 +477,26 @@ void smp_call_function_many(const struct cpumask *mask,
}
}
}
/**
* smp_call_function_many(): Run a function on a set of other CPUs.
* @mask: The set of cpus to run on (only runs on online subset).
* @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 (atomically) until function has completed
* on other CPUs.
*
* 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
* must be disabled when calling this function.
*/
void smp_call_function_many(const struct cpumask *mask,
smp_call_func_t func, void *info, bool wait)
{
smp_call_function_many_cond(mask, func, info, wait, NULL);
}
EXPORT_SYMBOL(smp_call_function_many);
/**
@ -668,11 +679,6 @@ EXPORT_SYMBOL(on_each_cpu_mask);
* @info: An arbitrary pointer to pass to both functions.
* @wait: If true, wait (atomically) until function has
* completed on other CPUs.
* @gfp_flags: GFP flags to use when allocating the cpumask
* used internally by the function.
*
* The function might sleep if the GFP flags indicates a non
* atomic allocation is allowed.
*
* Preemption is disabled to protect against CPUs going offline but not online.
* CPUs going online during the call will not be seen or sent an IPI.
@ -680,46 +686,27 @@ EXPORT_SYMBOL(on_each_cpu_mask);
* You must not call this function with disabled interrupts or
* from a hardware interrupt handler or from a bottom half handler.
*/
void on_each_cpu_cond_mask(bool (*cond_func)(int cpu, void *info),
smp_call_func_t func, void *info, bool wait,
gfp_t gfp_flags, const struct cpumask *mask)
void on_each_cpu_cond_mask(smp_cond_func_t cond_func, smp_call_func_t func,
void *info, bool wait, const struct cpumask *mask)
{
cpumask_var_t cpus;
int cpu, ret;
int cpu = get_cpu();
might_sleep_if(gfpflags_allow_blocking(gfp_flags));
smp_call_function_many_cond(mask, func, info, wait, cond_func);
if (cpumask_test_cpu(cpu, mask) && cond_func(cpu, info)) {
unsigned long flags;
if (likely(zalloc_cpumask_var(&cpus, (gfp_flags|__GFP_NOWARN)))) {
preempt_disable();
for_each_cpu(cpu, mask)
if (cond_func(cpu, info))
__cpumask_set_cpu(cpu, cpus);
on_each_cpu_mask(cpus, func, info, wait);
preempt_enable();
free_cpumask_var(cpus);
} else {
/*
* No free cpumask, bother. No matter, we'll
* just have to IPI them one by one.
*/
preempt_disable();
for_each_cpu(cpu, mask)
if (cond_func(cpu, info)) {
ret = smp_call_function_single(cpu, func,
info, wait);
WARN_ON_ONCE(ret);
}
preempt_enable();
local_irq_save(flags);
func(info);
local_irq_restore(flags);
}
put_cpu();
}
EXPORT_SYMBOL(on_each_cpu_cond_mask);
void on_each_cpu_cond(bool (*cond_func)(int cpu, void *info),
smp_call_func_t func, void *info, bool wait,
gfp_t gfp_flags)
void on_each_cpu_cond(smp_cond_func_t cond_func, smp_call_func_t func,
void *info, bool wait)
{
on_each_cpu_cond_mask(cond_func, func, info, wait, gfp_flags,
cpu_online_mask);
on_each_cpu_cond_mask(cond_func, func, info, wait, cpu_online_mask);
}
EXPORT_SYMBOL(on_each_cpu_cond);

View File

@ -68,9 +68,8 @@ EXPORT_SYMBOL(on_each_cpu_mask);
* Preemption is disabled here to make sure the cond_func is called under the
* same condtions in UP and SMP.
*/
void on_each_cpu_cond_mask(bool (*cond_func)(int cpu, void *info),
smp_call_func_t func, void *info, bool wait,
gfp_t gfp_flags, const struct cpumask *mask)
void on_each_cpu_cond_mask(smp_cond_func_t cond_func, smp_call_func_t func,
void *info, bool wait, const struct cpumask *mask)
{
unsigned long flags;
@ -84,11 +83,10 @@ void on_each_cpu_cond_mask(bool (*cond_func)(int cpu, void *info),
}
EXPORT_SYMBOL(on_each_cpu_cond_mask);
void on_each_cpu_cond(bool (*cond_func)(int cpu, void *info),
smp_call_func_t func, void *info, bool wait,
gfp_t gfp_flags)
void on_each_cpu_cond(smp_cond_func_t cond_func, smp_call_func_t func,
void *info, bool wait)
{
on_each_cpu_cond_mask(cond_func, func, info, wait, gfp_flags, NULL);
on_each_cpu_cond_mask(cond_func, func, info, wait, NULL);
}
EXPORT_SYMBOL(on_each_cpu_cond);

View File

@ -2341,7 +2341,7 @@ static bool has_cpu_slab(int cpu, void *info)
static void flush_all(struct kmem_cache *s)
{
on_each_cpu_cond(has_cpu_slab, flush_cpu_slab, s, 1, GFP_ATOMIC);
on_each_cpu_cond(has_cpu_slab, flush_cpu_slab, s, 1);
}
/*