summaryrefslogtreecommitdiffstats
path: root/kernel
diff options
context:
space:
mode:
Diffstat (limited to 'kernel')
-rw-r--r--kernel/cpu.c196
-rw-r--r--kernel/padata.c88
-rw-r--r--kernel/relay.c124
-rw-r--r--kernel/softirq.c27
4 files changed, 203 insertions, 232 deletions
diff --git a/kernel/cpu.c b/kernel/cpu.c
index c506485eaa75..7c783876cbcb 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -23,6 +23,8 @@
#include <linux/tick.h>
#include <linux/irq.h>
#include <linux/smpboot.h>
+#include <linux/relay.h>
+#include <linux/slab.h>
#include <trace/events/power.h>
#define CREATE_TRACE_POINTS
@@ -73,15 +75,15 @@ static DEFINE_PER_CPU(struct cpuhp_cpu_state, cpuhp_state);
struct cpuhp_step {
const char *name;
union {
- int (*startup)(unsigned int cpu);
- int (*startup_multi)(unsigned int cpu,
- struct hlist_node *node);
- };
+ int (*single)(unsigned int cpu);
+ int (*multi)(unsigned int cpu,
+ struct hlist_node *node);
+ } startup;
union {
- int (*teardown)(unsigned int cpu);
- int (*teardown_multi)(unsigned int cpu,
- struct hlist_node *node);
- };
+ int (*single)(unsigned int cpu);
+ int (*multi)(unsigned int cpu,
+ struct hlist_node *node);
+ } teardown;
struct hlist_head list;
bool skip_onerr;
bool cant_stop;
@@ -127,7 +129,7 @@ static int cpuhp_invoke_callback(unsigned int cpu, enum cpuhp_state state,
int ret, cnt;
if (!step->multi_instance) {
- cb = bringup ? step->startup : step->teardown;
+ cb = bringup ? step->startup.single : step->teardown.single;
if (!cb)
return 0;
trace_cpuhp_enter(cpu, st->target, state, cb);
@@ -135,7 +137,7 @@ static int cpuhp_invoke_callback(unsigned int cpu, enum cpuhp_state state,
trace_cpuhp_exit(cpu, st->state, state, ret);
return ret;
}
- cbm = bringup ? step->startup_multi : step->teardown_multi;
+ cbm = bringup ? step->startup.multi : step->teardown.multi;
if (!cbm)
return 0;
@@ -160,7 +162,7 @@ static int cpuhp_invoke_callback(unsigned int cpu, enum cpuhp_state state,
return 0;
err:
/* Rollback the instances if one failed */
- cbm = !bringup ? step->startup_multi : step->teardown_multi;
+ cbm = !bringup ? step->startup.multi : step->teardown.multi;
if (!cbm)
return ret;
@@ -331,10 +333,17 @@ void cpu_hotplug_disable(void)
}
EXPORT_SYMBOL_GPL(cpu_hotplug_disable);
+static void __cpu_hotplug_enable(void)
+{
+ if (WARN_ONCE(!cpu_hotplug_disabled, "Unbalanced cpu hotplug enable\n"))
+ return;
+ cpu_hotplug_disabled--;
+}
+
void cpu_hotplug_enable(void)
{
cpu_maps_update_begin();
- WARN_ON(--cpu_hotplug_disabled < 0);
+ __cpu_hotplug_enable();
cpu_maps_update_done();
}
EXPORT_SYMBOL_GPL(cpu_hotplug_enable);
@@ -401,12 +410,6 @@ static int notify_online(unsigned int cpu)
return 0;
}
-static int notify_starting(unsigned int cpu)
-{
- cpu_notify(CPU_STARTING, cpu);
- return 0;
-}
-
static int bringup_wait_for_ap(unsigned int cpu)
{
struct cpuhp_cpu_state *st = per_cpu_ptr(&cpuhp_state, cpu);
@@ -752,12 +755,6 @@ static int notify_down_prepare(unsigned int cpu)
return err;
}
-static int notify_dying(unsigned int cpu)
-{
- cpu_notify(CPU_DYING, cpu);
- return 0;
-}
-
/* Take this CPU down. */
static int take_cpu_down(void *_param)
{
@@ -816,7 +813,7 @@ static int takedown_cpu(unsigned int cpu)
BUG_ON(cpu_online(cpu));
/*
- * The migration_call() CPU_DYING callback will have removed all
+ * The CPUHP_AP_SCHED_MIGRATE_DYING callback will have removed all
* runnable tasks from the cpu, there's only the idle task left now
* that the migration thread is done doing the stop_machine thing.
*
@@ -869,7 +866,6 @@ void cpuhp_report_idle_dead(void)
#define notify_down_prepare NULL
#define takedown_cpu NULL
#define notify_dead NULL
-#define notify_dying NULL
#endif
#ifdef CONFIG_HOTPLUG_CPU
@@ -959,10 +955,9 @@ EXPORT_SYMBOL(cpu_down);
#endif /*CONFIG_HOTPLUG_CPU*/
/**
- * notify_cpu_starting(cpu) - call the CPU_STARTING notifiers
+ * notify_cpu_starting(cpu) - Invoke the callbacks on the starting CPU
* @cpu: cpu that just started
*
- * This function calls the cpu_chain notifiers with CPU_STARTING.
* It must be called by the arch code on the new cpu, before the new cpu
* enables interrupts and before the "boot" cpu returns from __cpu_up().
*/
@@ -1160,7 +1155,7 @@ void enable_nonboot_cpus(void)
/* Allow everyone to use the CPU hotplug again */
cpu_maps_update_begin();
- WARN_ON(--cpu_hotplug_disabled < 0);
+ __cpu_hotplug_enable();
if (cpumask_empty(frozen_cpus))
goto out;
@@ -1249,40 +1244,50 @@ core_initcall(cpu_hotplug_pm_sync_init);
static struct cpuhp_step cpuhp_bp_states[] = {
[CPUHP_OFFLINE] = {
.name = "offline",
- .startup = NULL,
- .teardown = NULL,
+ .startup.single = NULL,
+ .teardown.single = NULL,
},
#ifdef CONFIG_SMP
[CPUHP_CREATE_THREADS]= {
- .name = "threads:create",
- .startup = smpboot_create_threads,
- .teardown = NULL,
+ .name = "threads:prepare",
+ .startup.single = smpboot_create_threads,
+ .teardown.single = NULL,
.cant_stop = true,
},
[CPUHP_PERF_PREPARE] = {
- .name = "perf prepare",
- .startup = perf_event_init_cpu,
- .teardown = perf_event_exit_cpu,
+ .name = "perf:prepare",
+ .startup.single = perf_event_init_cpu,
+ .teardown.single = perf_event_exit_cpu,
},
[CPUHP_WORKQUEUE_PREP] = {
- .name = "workqueue prepare",
- .startup = workqueue_prepare_cpu,
- .teardown = NULL,
+ .name = "workqueue:prepare",
+ .startup.single = workqueue_prepare_cpu,
+ .teardown.single = NULL,
},
[CPUHP_HRTIMERS_PREPARE] = {
- .name = "hrtimers prepare",
- .startup = hrtimers_prepare_cpu,
- .teardown = hrtimers_dead_cpu,
+ .name = "hrtimers:prepare",
+ .startup.single = hrtimers_prepare_cpu,
+ .teardown.single = hrtimers_dead_cpu,
},
[CPUHP_SMPCFD_PREPARE] = {
- .name = "SMPCFD prepare",
- .startup = smpcfd_prepare_cpu,
- .teardown = smpcfd_dead_cpu,
+ .name = "smpcfd:prepare",
+ .startup.single = smpcfd_prepare_cpu,
+ .teardown.single = smpcfd_dead_cpu,
+ },
+ [CPUHP_RELAY_PREPARE] = {
+ .name = "relay:prepare",
+ .startup.single = relay_prepare_cpu,
+ .teardown.single = NULL,
+ },
+ [CPUHP_SLAB_PREPARE] = {
+ .name = "slab:prepare",
+ .startup.single = slab_prepare_cpu,
+ .teardown.single = slab_dead_cpu,
},
[CPUHP_RCUTREE_PREP] = {
- .name = "RCU-tree prepare",
- .startup = rcutree_prepare_cpu,
- .teardown = rcutree_dead_cpu,
+ .name = "RCU/tree:prepare",
+ .startup.single = rcutree_prepare_cpu,
+ .teardown.single = rcutree_dead_cpu,
},
/*
* Preparatory and dead notifiers. Will be replaced once the notifiers
@@ -1290,8 +1295,8 @@ static struct cpuhp_step cpuhp_bp_states[] = {
*/
[CPUHP_NOTIFY_PREPARE] = {
.name = "notify:prepare",
- .startup = notify_prepare,
- .teardown = notify_dead,
+ .startup.single = notify_prepare,
+ .teardown.single = notify_dead,
.skip_onerr = true,
.cant_stop = true,
},
@@ -1301,20 +1306,21 @@ static struct cpuhp_step cpuhp_bp_states[] = {
* otherwise a RCU stall occurs.
*/
[CPUHP_TIMERS_DEAD] = {
- .name = "timers dead",
- .startup = NULL,
- .teardown = timers_dead_cpu,
+ .name = "timers:dead",
+ .startup.single = NULL,
+ .teardown.single = timers_dead_cpu,
},
/* Kicks the plugged cpu into life */
[CPUHP_BRINGUP_CPU] = {
.name = "cpu:bringup",
- .startup = bringup_cpu,
- .teardown = NULL,
+ .startup.single = bringup_cpu,
+ .teardown.single = NULL,
.cant_stop = true,
},
[CPUHP_AP_SMPCFD_DYING] = {
- .startup = NULL,
- .teardown = smpcfd_dying_cpu,
+ .name = "smpcfd:dying",
+ .startup.single = NULL,
+ .teardown.single = smpcfd_dying_cpu,
},
/*
* Handled on controll processor until the plugged processor manages
@@ -1322,8 +1328,8 @@ static struct cpuhp_step cpuhp_bp_states[] = {
*/
[CPUHP_TEARDOWN_CPU] = {
.name = "cpu:teardown",
- .startup = NULL,
- .teardown = takedown_cpu,
+ .startup.single = NULL,
+ .teardown.single = takedown_cpu,
.cant_stop = true,
},
#else
@@ -1349,24 +1355,13 @@ static struct cpuhp_step cpuhp_ap_states[] = {
/* First state is scheduler control. Interrupts are disabled */
[CPUHP_AP_SCHED_STARTING] = {
.name = "sched:starting",
- .startup = sched_cpu_starting,
- .teardown = sched_cpu_dying,
+ .startup.single = sched_cpu_starting,
+ .teardown.single = sched_cpu_dying,
},
[CPUHP_AP_RCUTREE_DYING] = {
- .startup = NULL,
- .teardown = rcutree_dying_cpu,
- },
- /*
- * Low level startup/teardown notifiers. Run with interrupts
- * disabled. Will be removed once the notifiers are converted to
- * states.
- */
- [CPUHP_AP_NOTIFY_STARTING] = {
- .name = "notify:starting",
- .startup = notify_starting,
- .teardown = notify_dying,
- .skip_onerr = true,
- .cant_stop = true,
+ .name = "RCU/tree:dying",
+ .startup.single = NULL,
+ .teardown.single = rcutree_dying_cpu,
},
/* Entry state on starting. Interrupts enabled from here on. Transient
* state for synchronsization */
@@ -1375,24 +1370,24 @@ static struct cpuhp_step cpuhp_ap_states[] = {
},
/* Handle smpboot threads park/unpark */
[CPUHP_AP_SMPBOOT_THREADS] = {
- .name = "smpboot:threads",
- .startup = smpboot_unpark_threads,
- .teardown = NULL,
+ .name = "smpboot/threads:online",
+ .startup.single = smpboot_unpark_threads,
+ .teardown.single = NULL,
},
[CPUHP_AP_PERF_ONLINE] = {
- .name = "perf online",
- .startup = perf_event_init_cpu,
- .teardown = perf_event_exit_cpu,
+ .name = "perf:online",
+ .startup.single = perf_event_init_cpu,
+ .teardown.single = perf_event_exit_cpu,
},
[CPUHP_AP_WORKQUEUE_ONLINE] = {
- .name = "workqueue online",
- .startup = workqueue_online_cpu,
- .teardown = workqueue_offline_cpu,
+ .name = "workqueue:online",
+ .startup.single = workqueue_online_cpu,
+ .teardown.single = workqueue_offline_cpu,
},
[CPUHP_AP_RCUTREE_ONLINE] = {
- .name = "RCU-tree online",
- .startup = rcutree_online_cpu,
- .teardown = rcutree_offline_cpu,
+ .name = "RCU/tree:online",
+ .startup.single = rcutree_online_cpu,
+ .teardown.single = rcutree_offline_cpu,
},
/*
@@ -1401,8 +1396,8 @@ static struct cpuhp_step cpuhp_ap_states[] = {
*/
[CPUHP_AP_NOTIFY_ONLINE] = {
.name = "notify:online",
- .startup = notify_online,
- .teardown = notify_down_prepare,
+ .startup.single = notify_online,
+ .teardown.single = notify_down_prepare,
.skip_onerr = true,
},
#endif
@@ -1414,16 +1409,16 @@ static struct cpuhp_step cpuhp_ap_states[] = {
/* Last state is scheduler control setting the cpu active */
[CPUHP_AP_ACTIVE] = {
.name = "sched:active",
- .startup = sched_cpu_activate,
- .teardown = sched_cpu_deactivate,
+ .startup.single = sched_cpu_activate,
+ .teardown.single = sched_cpu_deactivate,
},
#endif
/* CPU is fully up and running. */
[CPUHP_ONLINE] = {
.name = "online",
- .startup = NULL,
- .teardown = NULL,
+ .startup.single = NULL,
+ .teardown.single = NULL,
},
};
@@ -1446,8 +1441,8 @@ static void cpuhp_store_callbacks(enum cpuhp_state state,
mutex_lock(&cpuhp_state_mutex);
sp = cpuhp_get_step(state);
- sp->startup = startup;
- sp->teardown = teardown;
+ sp->startup.single = startup;
+ sp->teardown.single = teardown;
sp->name = name;
sp->multi_instance = multi_instance;
INIT_HLIST_HEAD(&sp->list);
@@ -1456,7 +1451,7 @@ static void cpuhp_store_callbacks(enum cpuhp_state state,
static void *cpuhp_get_teardown_cb(enum cpuhp_state state)
{
- return cpuhp_get_step(state)->teardown;
+ return cpuhp_get_step(state)->teardown.single;
}
/*
@@ -1469,7 +1464,8 @@ static int cpuhp_issue_call(int cpu, enum cpuhp_state state, bool bringup,
struct cpuhp_step *sp = cpuhp_get_step(state);
int ret;
- if ((bringup && !sp->startup) || (!bringup && !sp->teardown))
+ if ((bringup && !sp->startup.single) ||
+ (!bringup && !sp->teardown.single))
return 0;
/*
* The non AP bound callbacks can fail on bringup. On teardown
@@ -1547,7 +1543,7 @@ int __cpuhp_state_add_instance(enum cpuhp_state state, struct hlist_node *node,
get_online_cpus();
- if (!invoke || !sp->startup_multi)
+ if (!invoke || !sp->startup.multi)
goto add_node;
/*
@@ -1563,7 +1559,7 @@ int __cpuhp_state_add_instance(enum cpuhp_state state, struct hlist_node *node,
ret = cpuhp_issue_call(cpu, state, true, node);
if (ret) {
- if (sp->teardown_multi)
+ if (sp->teardown.multi)
cpuhp_rollback_install(cpu, state, node);
goto err;
}
diff --git a/kernel/padata.c b/kernel/padata.c
index 993278895ccc..7848f0566403 100644
--- a/kernel/padata.c
+++ b/kernel/padata.c
@@ -30,6 +30,7 @@
#include <linux/slab.h>
#include <linux/sysfs.h>
#include <linux/rcupdate.h>
+#include <linux/module.h>
#define MAX_OBJ_NUM 1000
@@ -769,52 +770,43 @@ static inline int pinst_has_cpu(struct padata_instance *pinst, int cpu)
cpumask_test_cpu(cpu, pinst->cpumask.cbcpu);
}
-
-static int padata_cpu_callback(struct notifier_block *nfb,
- unsigned long action, void *hcpu)
+static int padata_cpu_online(unsigned int cpu, struct hlist_node *node)
{
- int err;
struct padata_instance *pinst;
- int cpu = (unsigned long)hcpu;
+ int ret;
- pinst = container_of(nfb, struct padata_instance, cpu_notifier);
+ pinst = hlist_entry_safe(node, struct padata_instance, node);
+ if (!pinst_has_cpu(pinst, cpu))
+ return 0;
- switch (action) {
- case CPU_ONLINE:
- case CPU_ONLINE_FROZEN:
- case CPU_DOWN_FAILED:
- case CPU_DOWN_FAILED_FROZEN:
- if (!pinst_has_cpu(pinst, cpu))
- break;
- mutex_lock(&pinst->lock);
- err = __padata_add_cpu(pinst, cpu);
- mutex_unlock(&pinst->lock);
- if (err)
- return notifier_from_errno(err);
- break;
+ mutex_lock(&pinst->lock);
+ ret = __padata_add_cpu(pinst, cpu);
+ mutex_unlock(&pinst->lock);
+ return ret;
+}
- case CPU_DOWN_PREPARE:
- case CPU_DOWN_PREPARE_FROZEN:
- case CPU_UP_CANCELED:
- case CPU_UP_CANCELED_FROZEN:
- if (!pinst_has_cpu(pinst, cpu))
- break;
- mutex_lock(&pinst->lock);
- err = __padata_remove_cpu(pinst, cpu);
- mutex_unlock(&pinst->lock);
- if (err)
- return notifier_from_errno(err);
- break;
- }
+static int padata_cpu_prep_down(unsigned int cpu, struct hlist_node *node)
+{
+ struct padata_instance *pinst;
+ int ret;
+
+ pinst = hlist_entry_safe(node, struct padata_instance, node);
+ if (!pinst_has_cpu(pinst, cpu))
+ return 0;
- return NOTIFY_OK;
+ mutex_lock(&pinst->lock);
+ ret = __padata_remove_cpu(pinst, cpu);
+ mutex_unlock(&pinst->lock);
+ return ret;
}
+
+static enum cpuhp_state hp_online;
#endif
static void __padata_free(struct padata_instance *pinst)
{
#ifdef CONFIG_HOTPLUG_CPU
- unregister_hotcpu_notifier(&pinst->cpu_notifier);
+ cpuhp_state_remove_instance_nocalls(hp_online, &pinst->node);
#endif
padata_stop(pinst);
@@ -1012,11 +1004,8 @@ struct padata_instance *padata_alloc(struct workqueue_struct *wq,
mutex_init(&pinst->lock);
#ifdef CONFIG_HOTPLUG_CPU
- pinst->cpu_notifier.notifier_call = padata_cpu_callback;
- pinst->cpu_notifier.priority = 0;
- register_hotcpu_notifier(&pinst->cpu_notifier);
+ cpuhp_state_add_instance_nocalls(hp_online, &pinst->node);
#endif
-
return pinst;
err_free_masks:
@@ -1039,3 +1028,26 @@ void padata_free(struct padata_instance *pinst)
kobject_put(&pinst->kobj);
}
EXPORT_SYMBOL(padata_free);
+
+#ifdef CONFIG_HOTPLUG_CPU
+
+static __init int padata_driver_init(void)
+{
+ int ret;
+
+ ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, "padata:online",
+ padata_cpu_online,
+ padata_cpu_prep_down);
+ if (ret < 0)
+ return ret;
+ hp_online = ret;
+ return 0;
+}
+module_init(padata_driver_init);
+
+static __exit void padata_driver_exit(void)
+{
+ cpuhp_remove_multi_state(hp_online);
+}
+module_exit(padata_driver_exit);
+#endif
diff --git a/kernel/relay.c b/kernel/relay.c
index d797502140b9..fc9b4a4af463 100644
--- a/kernel/relay.c
+++ b/kernel/relay.c
@@ -214,7 +214,7 @@ static void relay_destroy_buf(struct rchan_buf *buf)
__free_page(buf->page_array[i]);
relay_free_page_array(buf->page_array);
}
- chan->buf[buf->cpu] = NULL;
+ *per_cpu_ptr(chan->buf, buf->cpu) = NULL;
kfree(buf->padding);
kfree(buf);
kref_put(&chan->kref, relay_destroy_channel);
@@ -382,20 +382,21 @@ static void __relay_reset(struct rchan_buf *buf, unsigned int init)
*/
void relay_reset(struct rchan *chan)
{
+ struct rchan_buf *buf;
unsigned int i;
if (!chan)
return;
- if (chan->is_global && chan->buf[0]) {
- __relay_reset(chan->buf[0], 0);
+ if (chan->is_global && (buf = *per_cpu_ptr(chan->buf, 0))) {
+ __relay_reset(buf, 0);
return;
}
mutex_lock(&relay_channels_mutex);
for_each_possible_cpu(i)
- if (chan->buf[i])
- __relay_reset(chan->buf[i], 0);
+ if ((buf = *per_cpu_ptr(chan->buf, i)))
+ __relay_reset(buf, 0);
mutex_unlock(&relay_channels_mutex);
}
EXPORT_SYMBOL_GPL(relay_reset);
@@ -440,7 +441,7 @@ static struct rchan_buf *relay_open_buf(struct rchan *chan, unsigned int cpu)
struct dentry *dentry;
if (chan->is_global)
- return chan->buf[0];
+ return *per_cpu_ptr(chan->buf, 0);
buf = relay_create_buf(chan);
if (!buf)
@@ -464,7 +465,7 @@ static struct rchan_buf *relay_open_buf(struct rchan *chan, unsigned int cpu)
__relay_reset(buf, 1);
if(chan->is_global) {
- chan->buf[0] = buf;
+ *per_cpu_ptr(chan->buf, 0) = buf;
buf->cpu = 0;
}
@@ -512,46 +513,25 @@ static void setup_callbacks(struct rchan *chan,
chan->cb = cb;
}
-/**
- * relay_hotcpu_callback - CPU hotplug callback
- * @nb: notifier block
- * @action: hotplug action to take
- * @hcpu: CPU number
- *
- * Returns the success/failure of the operation. (%NOTIFY_OK, %NOTIFY_BAD)
- */
-static int relay_hotcpu_callback(struct notifier_block *nb,
- unsigned long action,
- void *hcpu)
+int relay_prepare_cpu(unsigned int cpu)
{
- unsigned int hotcpu = (unsigned long)hcpu;
struct rchan *chan;
+ struct rchan_buf *buf;
- switch(action) {
- case CPU_UP_PREPARE:
- case CPU_UP_PREPARE_FROZEN:
- mutex_lock(&relay_channels_mutex);
- list_for_each_entry(chan, &relay_channels, list) {
- if (chan->buf[hotcpu])
- continue;
- chan->buf[hotcpu] = relay_open_buf(chan, hotcpu);
- if(!chan->buf[hotcpu]) {
- printk(KERN_ERR
- "relay_hotcpu_callback: cpu %d buffer "
- "creation failed\n", hotcpu);
- mutex_unlock(&relay_channels_mutex);
- return notifier_from_errno(-ENOMEM);
- }
+ mutex_lock(&relay_channels_mutex);
+ list_for_each_entry(chan, &relay_channels, list) {
+ if ((buf = *per_cpu_ptr(chan->buf, cpu)))
+ continue;
+ buf = relay_open_buf(chan, cpu);
+ if (!buf) {
+ pr_err("relay: cpu %d buffer creation failed\n", cpu);
+ mutex_unlock(&relay_channels_mutex);
+ return -ENOMEM;
}
- mutex_unlock(&relay_channels_mutex);
- break;
- case CPU_DEAD:
- case CPU_DEAD_FROZEN:
- /* No need to flush the cpu : will be flushed upon
- * final relay_flush() call. */
- break;
+ *per_cpu_ptr(chan->buf, cpu) = buf;
}
- return NOTIFY_OK;
+ mutex_unlock(&relay_channels_mutex);
+ return 0;
}
/**
@@ -583,6 +563,7 @@ struct rchan *relay_open(const char *base_filename,
{
unsigned int i;
struct rchan *chan;
+ struct rchan_buf *buf;
if (!(subbuf_size && n_subbufs))
return NULL;
@@ -593,6 +574,7 @@ struct rchan *relay_open(const char *base_filename,
if (!chan)
return NULL;
+ chan->buf = alloc_percpu(struct rchan_buf *);
chan->version = RELAYFS_CHANNEL_VERSION;
chan->n_subbufs = n_subbufs;
chan->subbuf_size = subbuf_size;
@@ -608,9 +590,10 @@ struct rchan *relay_open(const char *base_filename,
mutex_lock(&relay_channels_mutex);
for_each_online_cpu(i) {
- chan->buf[i] = relay_open_buf(chan, i);
- if (!chan->buf[i])
+ buf = relay_open_buf(chan, i);
+ if (!buf)
goto free_bufs;
+ *per_cpu_ptr(chan->buf, i) = buf;
}
list_add(&chan->list, &relay_channels);
mutex_unlock(&relay_channels_mutex);
@@ -619,8 +602,8 @@ struct rchan *relay_open(const char *base_filename,
free_bufs:
for_each_possible_cpu(i) {
- if (chan->buf[i])
- relay_close_buf(chan->buf[i]);
+ if ((buf = *per_cpu_ptr(chan->buf, i)))
+ relay_close_buf(buf);
}
kref_put(&chan->kref, relay_destroy_channel);
@@ -666,6 +649,7 @@ int relay_late_setup_files(struct rchan *chan,
unsigned int i, curr_cpu;
unsigned long flags;
struct dentry *dentry;
+ struct rchan_buf *buf;
struct rchan_percpu_buf_dispatcher disp;
if (!chan || !base_filename)
@@ -684,10 +668,11 @@ int relay_late_setup_files(struct rchan *chan,
if (chan->is_global) {
err = -EINVAL;
- if (!WARN_ON_ONCE(!chan->buf[0])) {
- dentry = relay_create_buf_file(chan, chan->buf[0], 0);
+ buf = *per_cpu_ptr(chan->buf, 0);
+ if (!WARN_ON_ONCE(!buf)) {
+ dentry = relay_create_buf_file(chan, buf, 0);
if (dentry && !WARN_ON_ONCE(!chan->is_global)) {
- relay_set_buf_dentry(chan->buf[0], dentry);
+ relay_set_buf_dentry(buf, dentry);
err = 0;
}
}
@@ -702,13 +687,14 @@ int relay_late_setup_files(struct rchan *chan,
* on all currently online CPUs.
*/
for_each_online_cpu(i) {
- if (unlikely(!chan->buf[i])) {
+ buf = *per_cpu_ptr(chan->buf, i);
+ if (unlikely(!buf)) {
WARN_ONCE(1, KERN_ERR "CPU has no buffer!\n");
err = -EINVAL;
break;
}
- dentry = relay_create_buf_file(chan, chan->buf[i], i);
+ dentry = relay_create_buf_file(chan, buf, i);
if (unlikely(!dentry)) {
err = -EINVAL;
break;
@@ -716,10 +702,10 @@ int relay_late_setup_files(struct rchan *chan,
if (curr_cpu == i) {
local_irq_save(flags);
- relay_set_buf_dentry(chan->buf[i], dentry);
+ relay_set_buf_dentry(buf, dentry);
local_irq_restore(flags);
} else {
- disp.buf = chan->buf[i];
+ disp.buf = buf;
disp.dentry = dentry;
smp_mb();
/* relay_channels_mutex must be held, so wait. */
@@ -822,11 +808,10 @@ void relay_subbufs_consumed(struct rchan *chan,
if (!chan)
return;
- if (cpu >= NR_CPUS || !chan->buf[cpu] ||
- subbufs_consumed > chan->n_subbufs)
+ buf = *per_cpu_ptr(chan->buf, cpu);
+ if (cpu >= NR_CPUS || !buf || subbufs_consumed > chan->n_subbufs)
return;
- buf = chan->buf[cpu];
if (subbufs_consumed > buf->subbufs_produced - buf->subbufs_consumed)
buf->subbufs_consumed = buf->subbufs_produced;
else
@@ -842,18 +827,19 @@ EXPORT_SYMBOL_GPL(relay_subbufs_consumed);
*/
void relay_close(struct rchan *chan)
{
+ struct rchan_buf *buf;
unsigned int i;
if (!chan)
return;
mutex_lock(&relay_channels_mutex);
- if (chan->is_global && chan->buf[0])
- relay_close_buf(chan->buf[0]);
+ if (chan->is_global && (buf = *per_cpu_ptr(chan->buf, 0)))
+ relay_close_buf(buf);
else
for_each_possible_cpu(i)
- if (chan->buf[i])
- relay_close_buf(chan->buf[i]);
+ if ((buf = *per_cpu_ptr(chan->buf, i)))
+ relay_close_buf(buf);
if (chan->last_toobig)
printk(KERN_WARNING "relay: one or more items not logged "
@@ -874,20 +860,21 @@ EXPORT_SYMBOL_GPL(relay_close);
*/
void relay_flush(struct rchan *chan)
{
+ struct rchan_buf *buf;
unsigned int i;
if (!chan)
return;
- if (chan->is_global && chan->buf[0]) {
- relay_switch_subbuf(chan->buf[0], 0);
+ if (chan->is_global && (buf = *per_cpu_ptr(chan->buf, 0))) {
+ relay_switch_subbuf(buf, 0);
return;
}
mutex_lock(&relay_channels_mutex);
for_each_possible_cpu(i)
- if (chan->buf[i])
- relay_switch_subbuf(chan->buf[i], 0);
+ if ((buf = *per_cpu_ptr(chan->buf, i)))
+ relay_switch_subbuf(buf, 0);
mutex_unlock(&relay_channels_mutex);
}
EXPORT_SYMBOL_GPL(relay_flush);
@@ -1377,12 +1364,3 @@ const struct file_operations relay_file_operations = {
.splice_read = relay_file_splice_read,
};
EXPORT_SYMBOL_GPL(relay_file_operations);
-
-static __init int relay_init(void)
-{
-
- hotcpu_notifier(relay_hotcpu_callback, 0);
- return 0;
-}
-
-early_initcall(relay_init);
diff --git a/kernel/softirq.c b/kernel/softirq.c
index 17caf4b63342..c372114494f5 100644
--- a/kernel/softirq.c
+++ b/kernel/softirq.c
@@ -700,7 +700,7 @@ void tasklet_kill_immediate(struct tasklet_struct *t, unsigned int cpu)
BUG();
}
-static void takeover_tasklets(unsigned int cpu)
+static int takeover_tasklets(unsigned int cpu)
{
/* CPU is dead, so no lock needed. */
local_irq_disable();
@@ -723,27 +723,12 @@ static void takeover_tasklets(unsigned int cpu)
raise_softirq_irqoff(HI_SOFTIRQ);
local_irq_enable();
+ return 0;
}
+#else
+#define takeover_tasklets NULL
#endif /* CONFIG_HOTPLUG_CPU */
-static int cpu_callback(struct notifier_block *nfb, unsigned long action,
- void *hcpu)
-{
- switch (action) {
-#ifdef CONFIG_HOTPLUG_CPU
- case CPU_DEAD:
- case CPU_DEAD_FROZEN:
- takeover_tasklets((unsigned long)hcpu);
- break;
-#endif /* CONFIG_HOTPLUG_CPU */
- }
- return NOTIFY_OK;
-}
-
-static struct notifier_block cpu_nfb = {
- .notifier_call = cpu_callback
-};
-
static struct smp_hotplug_thread softirq_threads = {
.store = &ksoftirqd,
.thread_should_run = ksoftirqd_should_run,
@@ -753,8 +738,8 @@ static struct smp_hotplug_thread softirq_threads = {
static __init int spawn_ksoftirqd(void)
{
- register_cpu_notifier(&cpu_nfb);
-
+ cpuhp_setup_state_nocalls(CPUHP_SOFTIRQ_DEAD, "softirq:dead", NULL,
+ takeover_tasklets);
BUG_ON(smpboot_register_percpu_thread(&softirq_threads));
return 0;
OpenPOWER on IntegriCloud