[GIT pull] smp/core for
From: Thomas Gleixner
Date: Mon Jan 27 2020 - 19:06:46 EST
Linus,
please pull the latest smp/core branch from:
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git smp-core-2020-01-28
up to: cb923159bbb8: smp: Remove allocation mask from on_each_cpu_cond.*()
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.
Thanks,
tglx
------------------>
Sebastian Andrzej Siewior (3):
smp: Use smp_cond_func_t as type for the conditional function
smp: Add a smp_cond_func_t argument to smp_call_function_many()
smp: Remove allocation mask from on_each_cpu_cond.*()
arch/x86/mm/tlb.c | 2 +-
fs/buffer.c | 2 +-
include/linux/smp.h | 11 +++---
kernel/smp.c | 99 +++++++++++++++++++++++------------------------------
kernel/up.c | 12 +++----
mm/slub.c | 2 +-
6 files changed, 56 insertions(+), 72 deletions(-)
diff --git a/arch/x86/mm/tlb.c b/arch/x86/mm/tlb.c
index e6a9edc5baaf..66f96f21a7b6 100644
--- a/arch/x86/mm/tlb.c
+++ b/arch/x86/mm/tlb.c
@@ -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);
}
/*
diff --git a/fs/buffer.c b/fs/buffer.c
index 18a87ec8a465..b8d28370cfd7 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -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);
diff --git a/include/linux/smp.h b/include/linux/smp.h
index 6fc856c9eda5..cbc9162689d0 100644
--- a/include/linux/smp.h
+++ b/include/linux/smp.h
@@ -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);
diff --git a/kernel/smp.c b/kernel/smp.c
index 7dbcb402c2fc..3b7bedc97af3 100644
--- a/kernel/smp.c
+++ b/kernel/smp.c
@@ -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;
-
- might_sleep_if(gfpflags_allow_blocking(gfp_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();
+ int cpu = get_cpu();
+
+ smp_call_function_many_cond(mask, func, info, wait, cond_func);
+ if (cpumask_test_cpu(cpu, mask) && cond_func(cpu, info)) {
+ unsigned long flags;
+
+ 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);
diff --git a/kernel/up.c b/kernel/up.c
index 862b460ab97a..53144d056252 100644
--- a/kernel/up.c
+++ b/kernel/up.c
@@ -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);
diff --git a/mm/slub.c b/mm/slub.c
index 8eafccf75940..2e1a57723f8e 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -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);
}
/*