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smp: Cleanup smp_call_function*()

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Get rid of the __call_single_node union and cleanup the API a little
to avoid external code relying on the structure layout as much.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
This commit is contained in:
Peter Zijlstra
2020-11-24 16:47:49 +01:00
parent 7a9f50a058
commit 545b8c8df4
13 changed files with 61 additions and 95 deletions
Download Patch File Download Diff File Expand all files Collapse all files
kernel/debug/debug_core.c
+3 -3
View File
@@ -225,8 +225,6 @@ NOKPROBE_SYMBOL(kgdb_skipexception);
* Default (weak) implementation for kgdb_roundup_cpus
*/
static DEFINE_PER_CPU(call_single_data_t, kgdb_roundup_csd);
void __weak kgdb_call_nmi_hook(void *ignored)
{
/*
@@ -241,6 +239,9 @@ void __weak kgdb_call_nmi_hook(void *ignored)
}
NOKPROBE_SYMBOL(kgdb_call_nmi_hook);
static DEFINE_PER_CPU(call_single_data_t, kgdb_roundup_csd) =
CSD_INIT(kgdb_call_nmi_hook, NULL);
void __weak kgdb_roundup_cpus(void)
{
call_single_data_t *csd;
@@ -267,7 +268,6 @@ void __weak kgdb_roundup_cpus(void)
continue;
kgdb_info[cpu].rounding_up = true;
csd->func = kgdb_call_nmi_hook;
ret = smp_call_function_single_async(cpu, csd);
if (ret)
kgdb_info[cpu].rounding_up = false;
kernel/sched/core.c
+2 -10
View File
@@ -320,14 +320,6 @@ void update_rq_clock(struct rq *rq)
update_rq_clock_task(rq, delta);
}
static inline void
rq_csd_init(struct rq *rq, call_single_data_t *csd, smp_call_func_t func)
{
csd->flags = 0;
csd->func = func;
csd->info = rq;
}
#ifdef CONFIG_SCHED_HRTICK
/*
* Use HR-timers to deliver accurate preemption points.
@@ -428,7 +420,7 @@ void hrtick_start(struct rq *rq, u64 delay)
static void hrtick_rq_init(struct rq *rq)
{
#ifdef CONFIG_SMP
rq_csd_init(rq, &rq->hrtick_csd, __hrtick_start);
INIT_CSD(&rq->hrtick_csd, __hrtick_start, rq);
#endif
hrtimer_init(&rq->hrtick_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_HARD);
rq->hrtick_timer.function = hrtick;
@@ -7774,7 +7766,7 @@ void __init sched_init(void)
rq->last_blocked_load_update_tick = jiffies;
atomic_set(&rq->nohz_flags, 0);
rq_csd_init(rq, &rq->nohz_csd, nohz_csd_func);
INIT_CSD(&rq->nohz_csd, nohz_csd_func, rq);
#endif
#ifdef CONFIG_HOTPLUG_CPU
rcuwait_init(&rq->hotplug_wait);
kernel/smp.c
+25 -25
View File
@@ -27,7 +27,7 @@
#include "smpboot.h"
#include "sched/smp.h"
#define CSD_TYPE(_csd) ((_csd)->flags & CSD_FLAG_TYPE_MASK)
#define CSD_TYPE(_csd) ((_csd)->node.u_flags & CSD_FLAG_TYPE_MASK)
struct call_function_data {
call_single_data_t __percpu *csd;
@@ -146,7 +146,7 @@ static __always_inline bool csd_lock_wait_toolong(call_single_data_t *csd, u64 t
bool firsttime;
u64 ts2, ts_delta;
call_single_data_t *cpu_cur_csd;
unsigned int flags = READ_ONCE(csd->flags);
unsigned int flags = READ_ONCE(csd->node.u_flags);
if (!(flags & CSD_FLAG_LOCK)) {
if (!unlikely(*bug_id))
@@ -224,14 +224,14 @@ static void csd_lock_record(call_single_data_t *csd)
static __always_inline void csd_lock_wait(call_single_data_t *csd)
{
smp_cond_load_acquire(&csd->flags, !(VAL & CSD_FLAG_LOCK));
smp_cond_load_acquire(&csd->node.u_flags, !(VAL & CSD_FLAG_LOCK));
}
#endif
static __always_inline void csd_lock(call_single_data_t *csd)
{
csd_lock_wait(csd);
csd->flags |= CSD_FLAG_LOCK;
csd->node.u_flags |= CSD_FLAG_LOCK;
/*
* prevent CPU from reordering the above assignment
@@ -243,12 +243,12 @@ static __always_inline void csd_lock(call_single_data_t *csd)
static __always_inline void csd_unlock(call_single_data_t *csd)
{
WARN_ON(!(csd->flags & CSD_FLAG_LOCK));
WARN_ON(!(csd->node.u_flags & CSD_FLAG_LOCK));
/*
* ensure we're all done before releasing data:
*/
smp_store_release(&csd->flags, 0);
smp_store_release(&csd->node.u_flags, 0);
}
static DEFINE_PER_CPU_SHARED_ALIGNED(call_single_data_t, csd_data);
@@ -300,7 +300,7 @@ static int generic_exec_single(int cpu, call_single_data_t *csd)
return -ENXIO;
}
__smp_call_single_queue(cpu, &csd->llist);
__smp_call_single_queue(cpu, &csd->node.llist);
return 0;
}
@@ -353,7 +353,7 @@ static void flush_smp_call_function_queue(bool warn_cpu_offline)
* We don't have to use the _safe() variant here
* because we are not invoking the IPI handlers yet.
*/
llist_for_each_entry(csd, entry, llist) {
llist_for_each_entry(csd, entry, node.llist) {
switch (CSD_TYPE(csd)) {
case CSD_TYPE_ASYNC:
case CSD_TYPE_SYNC:
@@ -378,16 +378,16 @@ static void flush_smp_call_function_queue(bool warn_cpu_offline)
* First; run all SYNC callbacks, people are waiting for us.
*/
prev = NULL;
llist_for_each_entry_safe(csd, csd_next, entry, llist) {
llist_for_each_entry_safe(csd, csd_next, entry, node.llist) {
/* Do we wait until *after* callback? */
if (CSD_TYPE(csd) == CSD_TYPE_SYNC) {
smp_call_func_t func = csd->func;
void *info = csd->info;
if (prev) {
prev->next = &csd_next->llist;
prev->next = &csd_next->node.llist;
} else {
entry = &csd_next->llist;
entry = &csd_next->node.llist;
}
csd_lock_record(csd);
@@ -395,7 +395,7 @@ static void flush_smp_call_function_queue(bool warn_cpu_offline)
csd_unlock(csd);
csd_lock_record(NULL);
} else {
prev = &csd->llist;
prev = &csd->node.llist;
}
}
@@ -406,14 +406,14 @@ static void flush_smp_call_function_queue(bool warn_cpu_offline)
* Second; run all !SYNC callbacks.
*/
prev = NULL;
llist_for_each_entry_safe(csd, csd_next, entry, llist) {
llist_for_each_entry_safe(csd, csd_next, entry, node.llist) {
int type = CSD_TYPE(csd);
if (type != CSD_TYPE_TTWU) {
if (prev) {
prev->next = &csd_next->llist;
prev->next = &csd_next->node.llist;
} else {
entry = &csd_next->llist;
entry = &csd_next->node.llist;
}
if (type == CSD_TYPE_ASYNC) {
@@ -429,7 +429,7 @@ static void flush_smp_call_function_queue(bool warn_cpu_offline)
}
} else {
prev = &csd->llist;
prev = &csd->node.llist;
}
}
@@ -465,7 +465,7 @@ int smp_call_function_single(int cpu, smp_call_func_t func, void *info,
{
call_single_data_t *csd;
call_single_data_t csd_stack = {
.flags = CSD_FLAG_LOCK | CSD_TYPE_SYNC,
.node = { .u_flags = CSD_FLAG_LOCK | CSD_TYPE_SYNC, },
};
int this_cpu;
int err;
@@ -502,8 +502,8 @@ int smp_call_function_single(int cpu, smp_call_func_t func, void *info,
csd->func = func;
csd->info = info;
#ifdef CONFIG_CSD_LOCK_WAIT_DEBUG
csd->src = smp_processor_id();
csd->dst = cpu;
csd->node.src = smp_processor_id();
csd->node.dst = cpu;
#endif
err = generic_exec_single(cpu, csd);
@@ -544,12 +544,12 @@ int smp_call_function_single_async(int cpu, call_single_data_t *csd)
preempt_disable();
if (csd->flags & CSD_FLAG_LOCK) {
if (csd->node.u_flags & CSD_FLAG_LOCK) {
err = -EBUSY;
goto out;
}
csd->flags = CSD_FLAG_LOCK;
csd->node.u_flags = CSD_FLAG_LOCK;
smp_wmb();
err = generic_exec_single(cpu, csd);
@@ -667,14 +667,14 @@ static void smp_call_function_many_cond(const struct cpumask *mask,
csd_lock(csd);
if (wait)
csd->flags |= CSD_TYPE_SYNC;
csd->node.u_flags |= CSD_TYPE_SYNC;
csd->func = func;
csd->info = info;
#ifdef CONFIG_CSD_LOCK_WAIT_DEBUG
csd->src = smp_processor_id();
csd->dst = cpu;
csd->node.src = smp_processor_id();
csd->node.dst = cpu;
#endif
if (llist_add(&csd->llist, &per_cpu(call_single_queue, cpu)))
if (llist_add(&csd->node.llist, &per_cpu(call_single_queue, cpu)))
__cpumask_set_cpu(cpu, cfd->cpumask_ipi);
}