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Diffstat (limited to 'kernel/trace/ring_buffer.c')
-rw-r--r--kernel/trace/ring_buffer.c115
1 files changed, 70 insertions, 45 deletions
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index a56e07c8d15b..5040d44fe5a3 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -9,7 +9,6 @@
#include <linux/trace_seq.h>
#include <linux/spinlock.h>
#include <linux/irq_work.h>
-#include <linux/debugfs.h>
#include <linux/uaccess.h>
#include <linux/hardirq.h>
#include <linux/kthread.h> /* for self test */
@@ -23,7 +22,6 @@
#include <linux/hash.h>
#include <linux/list.h>
#include <linux/cpu.h>
-#include <linux/fs.h>
#include <asm/local.h>
@@ -34,21 +32,19 @@ static void update_pages_handler(struct work_struct *work);
*/
int ring_buffer_print_entry_header(struct trace_seq *s)
{
- int ret;
-
- ret = trace_seq_puts(s, "# compressed entry header\n");
- ret = trace_seq_puts(s, "\ttype_len : 5 bits\n");
- ret = trace_seq_puts(s, "\ttime_delta : 27 bits\n");
- ret = trace_seq_puts(s, "\tarray : 32 bits\n");
- ret = trace_seq_putc(s, '\n');
- ret = trace_seq_printf(s, "\tpadding : type == %d\n",
- RINGBUF_TYPE_PADDING);
- ret = trace_seq_printf(s, "\ttime_extend : type == %d\n",
- RINGBUF_TYPE_TIME_EXTEND);
- ret = trace_seq_printf(s, "\tdata max type_len == %d\n",
- RINGBUF_TYPE_DATA_TYPE_LEN_MAX);
+ trace_seq_puts(s, "# compressed entry header\n");
+ trace_seq_puts(s, "\ttype_len : 5 bits\n");
+ trace_seq_puts(s, "\ttime_delta : 27 bits\n");
+ trace_seq_puts(s, "\tarray : 32 bits\n");
+ trace_seq_putc(s, '\n');
+ trace_seq_printf(s, "\tpadding : type == %d\n",
+ RINGBUF_TYPE_PADDING);
+ trace_seq_printf(s, "\ttime_extend : type == %d\n",
+ RINGBUF_TYPE_TIME_EXTEND);
+ trace_seq_printf(s, "\tdata max type_len == %d\n",
+ RINGBUF_TYPE_DATA_TYPE_LEN_MAX);
- return ret;
+ return !trace_seq_has_overflowed(s);
}
/*
@@ -419,38 +415,40 @@ static inline int test_time_stamp(u64 delta)
int ring_buffer_print_page_header(struct trace_seq *s)
{
struct buffer_data_page field;
- int ret;
- ret = trace_seq_printf(s, "\tfield: u64 timestamp;\t"
- "offset:0;\tsize:%u;\tsigned:%u;\n",
- (unsigned int)sizeof(field.time_stamp),
- (unsigned int)is_signed_type(u64));
-
- ret = trace_seq_printf(s, "\tfield: local_t commit;\t"
- "offset:%u;\tsize:%u;\tsigned:%u;\n",
- (unsigned int)offsetof(typeof(field), commit),
- (unsigned int)sizeof(field.commit),
- (unsigned int)is_signed_type(long));
-
- ret = trace_seq_printf(s, "\tfield: int overwrite;\t"
- "offset:%u;\tsize:%u;\tsigned:%u;\n",
- (unsigned int)offsetof(typeof(field), commit),
- 1,
- (unsigned int)is_signed_type(long));
-
- ret = trace_seq_printf(s, "\tfield: char data;\t"
- "offset:%u;\tsize:%u;\tsigned:%u;\n",
- (unsigned int)offsetof(typeof(field), data),
- (unsigned int)BUF_PAGE_SIZE,
- (unsigned int)is_signed_type(char));
+ trace_seq_printf(s, "\tfield: u64 timestamp;\t"
+ "offset:0;\tsize:%u;\tsigned:%u;\n",
+ (unsigned int)sizeof(field.time_stamp),
+ (unsigned int)is_signed_type(u64));
- return ret;
+ trace_seq_printf(s, "\tfield: local_t commit;\t"
+ "offset:%u;\tsize:%u;\tsigned:%u;\n",
+ (unsigned int)offsetof(typeof(field), commit),
+ (unsigned int)sizeof(field.commit),
+ (unsigned int)is_signed_type(long));
+
+ trace_seq_printf(s, "\tfield: int overwrite;\t"
+ "offset:%u;\tsize:%u;\tsigned:%u;\n",
+ (unsigned int)offsetof(typeof(field), commit),
+ 1,
+ (unsigned int)is_signed_type(long));
+
+ trace_seq_printf(s, "\tfield: char data;\t"
+ "offset:%u;\tsize:%u;\tsigned:%u;\n",
+ (unsigned int)offsetof(typeof(field), data),
+ (unsigned int)BUF_PAGE_SIZE,
+ (unsigned int)is_signed_type(char));
+
+ return !trace_seq_has_overflowed(s);
}
struct rb_irq_work {
struct irq_work work;
wait_queue_head_t waiters;
+ wait_queue_head_t full_waiters;
bool waiters_pending;
+ bool full_waiters_pending;
+ bool wakeup_full;
};
/*
@@ -532,6 +530,10 @@ static void rb_wake_up_waiters(struct irq_work *work)
struct rb_irq_work *rbwork = container_of(work, struct rb_irq_work, work);
wake_up_all(&rbwork->waiters);
+ if (rbwork->wakeup_full) {
+ rbwork->wakeup_full = false;
+ wake_up_all(&rbwork->full_waiters);
+ }
}
/**
@@ -556,9 +558,11 @@ int ring_buffer_wait(struct ring_buffer *buffer, int cpu, bool full)
* data in any cpu buffer, or a specific buffer, put the
* caller on the appropriate wait queue.
*/
- if (cpu == RING_BUFFER_ALL_CPUS)
+ if (cpu == RING_BUFFER_ALL_CPUS) {
work = &buffer->irq_work;
- else {
+ /* Full only makes sense on per cpu reads */
+ full = false;
+ } else {
if (!cpumask_test_cpu(cpu, buffer->cpumask))
return -ENODEV;
cpu_buffer = buffer->buffers[cpu];
@@ -567,7 +571,10 @@ int ring_buffer_wait(struct ring_buffer *buffer, int cpu, bool full)
while (true) {
- prepare_to_wait(&work->waiters, &wait, TASK_INTERRUPTIBLE);
+ if (full)
+ prepare_to_wait(&work->full_waiters, &wait, TASK_INTERRUPTIBLE);
+ else
+ prepare_to_wait(&work->waiters, &wait, TASK_INTERRUPTIBLE);
/*
* The events can happen in critical sections where
@@ -589,7 +596,10 @@ int ring_buffer_wait(struct ring_buffer *buffer, int cpu, bool full)
* that is necessary is that the wake up happens after
* a task has been queued. It's OK for spurious wake ups.
*/
- work->waiters_pending = true;
+ if (full)
+ work->full_waiters_pending = true;
+ else
+ work->waiters_pending = true;
if (signal_pending(current)) {
ret = -EINTR;
@@ -618,7 +628,10 @@ int ring_buffer_wait(struct ring_buffer *buffer, int cpu, bool full)
schedule();
}
- finish_wait(&work->waiters, &wait);
+ if (full)
+ finish_wait(&work->full_waiters, &wait);
+ else
+ finish_wait(&work->waiters, &wait);
return ret;
}
@@ -1233,6 +1246,7 @@ rb_allocate_cpu_buffer(struct ring_buffer *buffer, int nr_pages, int cpu)
init_completion(&cpu_buffer->update_done);
init_irq_work(&cpu_buffer->irq_work.work, rb_wake_up_waiters);
init_waitqueue_head(&cpu_buffer->irq_work.waiters);
+ init_waitqueue_head(&cpu_buffer->irq_work.full_waiters);
bpage = kzalloc_node(ALIGN(sizeof(*bpage), cache_line_size()),
GFP_KERNEL, cpu_to_node(cpu));
@@ -2804,6 +2818,8 @@ static void rb_commit(struct ring_buffer_per_cpu *cpu_buffer,
static __always_inline void
rb_wakeups(struct ring_buffer *buffer, struct ring_buffer_per_cpu *cpu_buffer)
{
+ bool pagebusy;
+
if (buffer->irq_work.waiters_pending) {
buffer->irq_work.waiters_pending = false;
/* irq_work_queue() supplies it's own memory barriers */
@@ -2815,6 +2831,15 @@ rb_wakeups(struct ring_buffer *buffer, struct ring_buffer_per_cpu *cpu_buffer)
/* irq_work_queue() supplies it's own memory barriers */
irq_work_queue(&cpu_buffer->irq_work.work);
}
+
+ pagebusy = cpu_buffer->reader_page == cpu_buffer->commit_page;
+
+ if (!pagebusy && cpu_buffer->irq_work.full_waiters_pending) {
+ cpu_buffer->irq_work.wakeup_full = true;
+ cpu_buffer->irq_work.full_waiters_pending = false;
+ /* irq_work_queue() supplies it's own memory barriers */
+ irq_work_queue(&cpu_buffer->irq_work.work);
+ }
}
/**
generated by cgit v1.2.3 (git 2.0.4) at 2025-09-09 00:34:08 +0000