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-rw-r--r--kernel/printk/printk.c25
-rw-r--r--kernel/time/tick-sched.c33
-rw-r--r--kernel/trace/ring_buffer.c137
-rw-r--r--kernel/trace/trace.c15
4 files changed, 86 insertions, 124 deletions
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index f7a55e9ff2f7..577f2288d19f 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -2166,27 +2166,20 @@ void resume_console(void)
/**
* console_cpu_notify - print deferred console messages after CPU hotplug
- * @self: notifier struct
- * @action: CPU hotplug event
- * @hcpu: unused
+ * @cpu: unused
*
* If printk() is called from a CPU that is not online yet, the messages
* will be spooled but will not show up on the console. This function is
* called when a new CPU comes online (or fails to come up), and ensures
* that any such output gets printed.
*/
-static int console_cpu_notify(struct notifier_block *self,
- unsigned long action, void *hcpu)
-{
- switch (action) {
- case CPU_ONLINE:
- case CPU_DEAD:
- case CPU_DOWN_FAILED:
- case CPU_UP_CANCELED:
+static int console_cpu_notify(unsigned int cpu)
+{
+ if (!cpuhp_tasks_frozen) {
console_lock();
console_unlock();
}
- return NOTIFY_OK;
+ return 0;
}
/**
@@ -2824,6 +2817,7 @@ EXPORT_SYMBOL(unregister_console);
static int __init printk_late_init(void)
{
struct console *con;
+ int ret;
for_each_console(con) {
if (!keep_bootcon && con->flags & CON_BOOT) {
@@ -2838,7 +2832,12 @@ static int __init printk_late_init(void)
unregister_console(con);
}
}
- hotcpu_notifier(console_cpu_notify, 0);
+ ret = cpuhp_setup_state_nocalls(CPUHP_PRINTK_DEAD, "printk:dead", NULL,
+ console_cpu_notify);
+ WARN_ON(ret < 0);
+ ret = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, "printk:online",
+ console_cpu_notify, NULL);
+ WARN_ON(ret < 0);
return 0;
}
late_initcall(printk_late_init);
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 3bcb61b52f6c..71496a20e670 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -390,24 +390,16 @@ static int __init tick_nohz_full_setup(char *str)
}
__setup("nohz_full=", tick_nohz_full_setup);
-static int tick_nohz_cpu_down_callback(struct notifier_block *nfb,
- unsigned long action,
- void *hcpu)
+static int tick_nohz_cpu_down(unsigned int cpu)
{
- unsigned int cpu = (unsigned long)hcpu;
-
- switch (action & ~CPU_TASKS_FROZEN) {
- case CPU_DOWN_PREPARE:
- /*
- * The boot CPU handles housekeeping duty (unbound timers,
- * workqueues, timekeeping, ...) on behalf of full dynticks
- * CPUs. It must remain online when nohz full is enabled.
- */
- if (tick_nohz_full_running && tick_do_timer_cpu == cpu)
- return NOTIFY_BAD;
- break;
- }
- return NOTIFY_OK;
+ /*
+ * The boot CPU handles housekeeping duty (unbound timers,
+ * workqueues, timekeeping, ...) on behalf of full dynticks
+ * CPUs. It must remain online when nohz full is enabled.
+ */
+ if (tick_nohz_full_running && tick_do_timer_cpu == cpu)
+ return -EBUSY;
+ return 0;
}
static int tick_nohz_init_all(void)
@@ -428,7 +420,7 @@ static int tick_nohz_init_all(void)
void __init tick_nohz_init(void)
{
- int cpu;
+ int cpu, ret;
if (!tick_nohz_full_running) {
if (tick_nohz_init_all() < 0)
@@ -469,7 +461,10 @@ void __init tick_nohz_init(void)
for_each_cpu(cpu, tick_nohz_full_mask)
context_tracking_cpu_set(cpu);
- cpu_notifier(tick_nohz_cpu_down_callback, 0);
+ ret = cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN,
+ "kernel/nohz:predown", NULL,
+ tick_nohz_cpu_down);
+ WARN_ON(ret < 0);
pr_info("NO_HZ: Full dynticks CPUs: %*pbl.\n",
cpumask_pr_args(tick_nohz_full_mask));
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 9c143739b8d7..89a2611a1635 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -479,9 +479,7 @@ struct ring_buffer {
struct ring_buffer_per_cpu **buffers;
-#ifdef CONFIG_HOTPLUG_CPU
- struct notifier_block cpu_notify;
-#endif
+ struct hlist_node node;
u64 (*clock)(void);
struct rb_irq_work irq_work;
@@ -1274,11 +1272,6 @@ static void rb_free_cpu_buffer(struct ring_buffer_per_cpu *cpu_buffer)
kfree(cpu_buffer);
}
-#ifdef CONFIG_HOTPLUG_CPU
-static int rb_cpu_notify(struct notifier_block *self,
- unsigned long action, void *hcpu);
-#endif
-
/**
* __ring_buffer_alloc - allocate a new ring_buffer
* @size: the size in bytes per cpu that is needed.
@@ -1296,6 +1289,7 @@ struct ring_buffer *__ring_buffer_alloc(unsigned long size, unsigned flags,
long nr_pages;
int bsize;
int cpu;
+ int ret;
/* keep it in its own cache line */
buffer = kzalloc(ALIGN(sizeof(*buffer), cache_line_size()),
@@ -1303,7 +1297,7 @@ struct ring_buffer *__ring_buffer_alloc(unsigned long size, unsigned flags,
if (!buffer)
return NULL;
- if (!alloc_cpumask_var(&buffer->cpumask, GFP_KERNEL))
+ if (!zalloc_cpumask_var(&buffer->cpumask, GFP_KERNEL))
goto fail_free_buffer;
nr_pages = DIV_ROUND_UP(size, BUF_PAGE_SIZE);
@@ -1318,17 +1312,6 @@ struct ring_buffer *__ring_buffer_alloc(unsigned long size, unsigned flags,
if (nr_pages < 2)
nr_pages = 2;
- /*
- * In case of non-hotplug cpu, if the ring-buffer is allocated
- * in early initcall, it will not be notified of secondary cpus.
- * In that off case, we need to allocate for all possible cpus.
- */
-#ifdef CONFIG_HOTPLUG_CPU
- cpu_notifier_register_begin();
- cpumask_copy(buffer->cpumask, cpu_online_mask);
-#else
- cpumask_copy(buffer->cpumask, cpu_possible_mask);
-#endif
buffer->cpus = nr_cpu_ids;
bsize = sizeof(void *) * nr_cpu_ids;
@@ -1337,19 +1320,15 @@ struct ring_buffer *__ring_buffer_alloc(unsigned long size, unsigned flags,
if (!buffer->buffers)
goto fail_free_cpumask;
- for_each_buffer_cpu(buffer, cpu) {
- buffer->buffers[cpu] =
- rb_allocate_cpu_buffer(buffer, nr_pages, cpu);
- if (!buffer->buffers[cpu])
- goto fail_free_buffers;
- }
+ cpu = raw_smp_processor_id();
+ cpumask_set_cpu(cpu, buffer->cpumask);
+ buffer->buffers[cpu] = rb_allocate_cpu_buffer(buffer, nr_pages, cpu);
+ if (!buffer->buffers[cpu])
+ goto fail_free_buffers;
-#ifdef CONFIG_HOTPLUG_CPU
- buffer->cpu_notify.notifier_call = rb_cpu_notify;
- buffer->cpu_notify.priority = 0;
- __register_cpu_notifier(&buffer->cpu_notify);
- cpu_notifier_register_done();
-#endif
+ ret = cpuhp_state_add_instance(CPUHP_TRACE_RB_PREPARE, &buffer->node);
+ if (ret < 0)
+ goto fail_free_buffers;
mutex_init(&buffer->mutex);
@@ -1364,9 +1343,6 @@ struct ring_buffer *__ring_buffer_alloc(unsigned long size, unsigned flags,
fail_free_cpumask:
free_cpumask_var(buffer->cpumask);
-#ifdef CONFIG_HOTPLUG_CPU
- cpu_notifier_register_done();
-#endif
fail_free_buffer:
kfree(buffer);
@@ -1383,18 +1359,11 @@ ring_buffer_free(struct ring_buffer *buffer)
{
int cpu;
-#ifdef CONFIG_HOTPLUG_CPU
- cpu_notifier_register_begin();
- __unregister_cpu_notifier(&buffer->cpu_notify);
-#endif
+ cpuhp_state_remove_instance(CPUHP_TRACE_RB_PREPARE, &buffer->node);
for_each_buffer_cpu(buffer, cpu)
rb_free_cpu_buffer(buffer->buffers[cpu]);
-#ifdef CONFIG_HOTPLUG_CPU
- cpu_notifier_register_done();
-#endif
-
kfree(buffer->buffers);
free_cpumask_var(buffer->cpumask);
@@ -4633,62 +4602,48 @@ int ring_buffer_read_page(struct ring_buffer *buffer,
}
EXPORT_SYMBOL_GPL(ring_buffer_read_page);
-#ifdef CONFIG_HOTPLUG_CPU
-static int rb_cpu_notify(struct notifier_block *self,
- unsigned long action, void *hcpu)
+/*
+ * We only allocate new buffers, never free them if the CPU goes down.
+ * If we were to free the buffer, then the user would lose any trace that was in
+ * the buffer.
+ */
+int trace_rb_cpu_prepare(unsigned int cpu, struct hlist_node *node)
{
- struct ring_buffer *buffer =
- container_of(self, struct ring_buffer, cpu_notify);
- long cpu = (long)hcpu;
+ struct ring_buffer *buffer;
long nr_pages_same;
int cpu_i;
unsigned long nr_pages;
- switch (action) {
- case CPU_UP_PREPARE:
- case CPU_UP_PREPARE_FROZEN:
- if (cpumask_test_cpu(cpu, buffer->cpumask))
- return NOTIFY_OK;
-
- nr_pages = 0;
- nr_pages_same = 1;
- /* check if all cpu sizes are same */
- for_each_buffer_cpu(buffer, cpu_i) {
- /* fill in the size from first enabled cpu */
- if (nr_pages == 0)
- nr_pages = buffer->buffers[cpu_i]->nr_pages;
- if (nr_pages != buffer->buffers[cpu_i]->nr_pages) {
- nr_pages_same = 0;
- break;
- }
- }
- /* allocate minimum pages, user can later expand it */
- if (!nr_pages_same)
- nr_pages = 2;
- buffer->buffers[cpu] =
- rb_allocate_cpu_buffer(buffer, nr_pages, cpu);
- if (!buffer->buffers[cpu]) {
- WARN(1, "failed to allocate ring buffer on CPU %ld\n",
- cpu);
- return NOTIFY_OK;
+ buffer = container_of(node, struct ring_buffer, node);
+ if (cpumask_test_cpu(cpu, buffer->cpumask))
+ return 0;
+
+ nr_pages = 0;
+ nr_pages_same = 1;
+ /* check if all cpu sizes are same */
+ for_each_buffer_cpu(buffer, cpu_i) {
+ /* fill in the size from first enabled cpu */
+ if (nr_pages == 0)
+ nr_pages = buffer->buffers[cpu_i]->nr_pages;
+ if (nr_pages != buffer->buffers[cpu_i]->nr_pages) {
+ nr_pages_same = 0;
+ break;
}
- smp_wmb();
- cpumask_set_cpu(cpu, buffer->cpumask);
- break;
- case CPU_DOWN_PREPARE:
- case CPU_DOWN_PREPARE_FROZEN:
- /*
- * Do nothing.
- * If we were to free the buffer, then the user would
- * lose any trace that was in the buffer.
- */
- break;
- default:
- break;
}
- return NOTIFY_OK;
+ /* allocate minimum pages, user can later expand it */
+ if (!nr_pages_same)
+ nr_pages = 2;
+ buffer->buffers[cpu] =
+ rb_allocate_cpu_buffer(buffer, nr_pages, cpu);
+ if (!buffer->buffers[cpu]) {
+ WARN(1, "failed to allocate ring buffer on CPU %u\n",
+ cpu);
+ return -ENOMEM;
+ }
+ smp_wmb();
+ cpumask_set_cpu(cpu, buffer->cpumask);
+ return 0;
}
-#endif
#ifdef CONFIG_RING_BUFFER_STARTUP_TEST
/*
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 8696ce6bf2f6..465d56febc5b 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -7659,10 +7659,21 @@ __init static int tracer_alloc_buffers(void)
raw_spin_lock_init(&global_trace.start_lock);
+ /*
+ * The prepare callbacks allocates some memory for the ring buffer. We
+ * don't free the buffer if the if the CPU goes down. If we were to free
+ * the buffer, then the user would lose any trace that was in the
+ * buffer. The memory will be removed once the "instance" is removed.
+ */
+ ret = cpuhp_setup_state_multi(CPUHP_TRACE_RB_PREPARE,
+ "trace/RB:preapre", trace_rb_cpu_prepare,
+ NULL);
+ if (ret < 0)
+ goto out_free_cpumask;
/* Used for event triggers */
temp_buffer = ring_buffer_alloc(PAGE_SIZE, RB_FL_OVERWRITE);
if (!temp_buffer)
- goto out_free_cpumask;
+ goto out_rm_hp_state;
if (trace_create_savedcmd() < 0)
goto out_free_temp_buffer;
@@ -7723,6 +7734,8 @@ out_free_savedcmd:
free_saved_cmdlines_buffer(savedcmd);
out_free_temp_buffer:
ring_buffer_free(temp_buffer);
+out_rm_hp_state:
+ cpuhp_remove_multi_state(CPUHP_TRACE_RB_PREPARE);
out_free_cpumask:
free_cpumask_var(global_trace.tracing_cpumask);
out_free_buffer_mask:
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-16 15:54:07 +0000