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smp: Cleanup smp_call_function*() 

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>
zero-sugar-mainline-defconfig
Peter Zijlstra 2020-06-15 11:29:31 +02:00
parent 7a9f50a058
commit 545b8c8df4
13 changed files with 61 additions and 95 deletions
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5
arch/mips/kernel/process.c
View File

@ -702,7 +702,6 @@ unsigned long arch_align_stack(unsigned long sp)
return sp & ALMASK;
}
static DEFINE_PER_CPU(call_single_data_t, backtrace_csd);
static struct cpumask backtrace_csd_busy;
static void handle_backtrace(void *info)
@ -711,6 +710,9 @@ static void handle_backtrace(void *info)
cpumask_clear_cpu(smp_processor_id(), &backtrace_csd_busy);
}
static DEFINE_PER_CPU(call_single_data_t, backtrace_csd) =
CSD_INIT(handle_backtrace, NULL);
static void raise_backtrace(cpumask_t *mask)
{
call_single_data_t *csd;
@ -730,7 +732,6 @@ static void raise_backtrace(cpumask_t *mask)
}
csd = &per_cpu(backtrace_csd, cpu);
csd->func = handle_backtrace;
smp_call_function_single_async(cpu, csd);
}
}

27
arch/mips/kernel/smp.c
View File

@ -687,7 +687,13 @@ EXPORT_SYMBOL(flush_tlb_one);
#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
static DEFINE_PER_CPU(call_single_data_t, tick_broadcast_csd);
static void tick_broadcast_callee(void *info)
{
tick_receive_broadcast();
}
static DEFINE_PER_CPU(call_single_data_t, tick_broadcast_csd) =
CSD_INIT(tick_broadcast_callee, NULL);
void tick_broadcast(const struct cpumask *mask)
{
@ -700,23 +706,4 @@ void tick_broadcast(const struct cpumask *mask)
}
}
static void tick_broadcast_callee(void *info)
{
tick_receive_broadcast();
}
static int __init tick_broadcast_init(void)
{
call_single_data_t *csd;
int cpu;
for (cpu = 0; cpu < NR_CPUS; cpu++) {
csd = &per_cpu(tick_broadcast_csd, cpu);
csd->func = tick_broadcast_callee;
}
return 0;
}
early_initcall(tick_broadcast_init);
#endif /* CONFIG_GENERIC_CLOCKEVENTS_BROADCAST */

4
arch/s390/pci/pci_irq.c
View File

@ -178,9 +178,7 @@ static void zpci_handle_fallback_irq(void)
if (atomic_inc_return(&cpu_data->scheduled) > 1)
continue;
cpu_data->csd.func = zpci_handle_remote_irq;
cpu_data->csd.info = &cpu_data->scheduled;
cpu_data->csd.flags = 0;
INIT_CSD(&cpu_data->csd, zpci_handle_remote_irq, &cpu_data->scheduled);
smp_call_function_single_async(cpu, &cpu_data->csd);
}
}

7
arch/x86/kernel/cpuid.c
View File

@ -74,10 +74,9 @@ static ssize_t cpuid_read(struct file *file, char __user *buf,
init_completion(&cmd.done);
for (; count; count -= 16) {
call_single_data_t csd = {
.func = cpuid_smp_cpuid,
.info = &cmd,
};
call_single_data_t csd;
INIT_CSD(&csd, cpuid_smp_cpuid, &cmd);
cmd.regs.eax = pos;
cmd.regs.ecx = pos >> 32;

7
arch/x86/lib/msr-smp.c
View File

@ -169,12 +169,11 @@ static void __wrmsr_safe_on_cpu(void *info)
int rdmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h)
{
struct msr_info_completion rv;
call_single_data_t csd = {
.func = __rdmsr_safe_on_cpu,
.info = &rv,
};
call_single_data_t csd;
int err;
INIT_CSD(&csd, __rdmsr_safe_on_cpu, &rv);
memset(&rv, 0, sizeof(rv));
init_completion(&rv.done);
rv.msr.msr_no = msr_no;

4
block/blk-mq.c
View File

@ -671,9 +671,7 @@ bool blk_mq_complete_request_remote(struct request *rq)
return false;
if (blk_mq_complete_need_ipi(rq)) {
rq->csd.func = __blk_mq_complete_request_remote;
rq->csd.info = rq;
rq->csd.flags = 0;
INIT_CSD(&rq->csd, __blk_mq_complete_request_remote, rq);
smp_call_function_single_async(rq->mq_ctx->cpu, &rq->csd);
} else {
if (rq->q->nr_hw_queues > 1)

3
drivers/cpuidle/coupled.c
View File

@ -674,8 +674,7 @@ have_coupled:
coupled->refcnt++;
csd = &per_cpu(cpuidle_coupled_poke_cb, dev->cpu);
csd->func = cpuidle_coupled_handle_poke;
csd->info = (void *)(unsigned long)dev->cpu;
INIT_CSD(csd, cpuidle_coupled_handle_poke, (void *)(unsigned long)dev->cpu);
return 0;
}

9
drivers/net/ethernet/cavium/liquidio/lio_core.c
View File

@ -729,13 +729,8 @@ static void liquidio_napi_drv_callback(void *arg)
droq->cpu_id == this_cpu) {
napi_schedule_irqoff(&droq->napi);
} else {
call_single_data_t *csd = &droq->csd;
csd->func = napi_schedule_wrapper;
csd->info = &droq->napi;
csd->flags = 0;
smp_call_function_single_async(droq->cpu_id, csd);
INIT_CSD(&droq->csd, napi_schedule_wrapper, &droq->napi);
smp_call_function_single_async(droq->cpu_id, &droq->csd);
}
}

19
include/linux/smp.h
View File

@ -21,24 +21,23 @@ typedef bool (*smp_cond_func_t)(int cpu, void *info);
* structure shares (partial) layout with struct irq_work
*/
struct __call_single_data {
union {
struct __call_single_node node;
struct {
struct llist_node llist;
unsigned int flags;
#ifdef CONFIG_64BIT
u16 src, dst;
#endif
};
};
struct __call_single_node node;
smp_call_func_t func;
void *info;
};
#define CSD_INIT(_func, _info) \
(struct __call_single_data){ .func = (_func), .info = (_info), }
/* Use __aligned() to avoid to use 2 cache lines for 1 csd */
typedef struct __call_single_data call_single_data_t
__aligned(sizeof(struct __call_single_data));
#define INIT_CSD(_csd, _func, _info) \
do { \
*(_csd) = CSD_INIT((_func), (_info)); \
} while (0)
/*
* Enqueue a llist_node on the call_single_queue; be very careful, read
* flush_smp_call_function_queue() in detail.

6
kernel/debug/debug_core.c
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;

12
kernel/sched/core.c
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);

50
kernel/smp.c
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);
}

3
net/core/dev.c
View File

@ -11165,8 +11165,7 @@ static int __init net_dev_init(void)
INIT_LIST_HEAD(&sd->poll_list);
sd->output_queue_tailp = &sd->output_queue;
#ifdef CONFIG_RPS
sd->csd.func = rps_trigger_softirq;
sd->csd.info = sd;
INIT_CSD(&sd->csd, rps_trigger_softirq, sd);
sd->cpu = i;
#endif