#define for_each_buffer_cpu(buffer, cpu) \
for_each_cpu(cpu, buffer->cpumask)
+#define for_each_online_buffer_cpu(buffer, cpu) \
+ for_each_cpu_and(cpu, buffer->cpumask, cpu_online_mask)
+
#define TS_SHIFT 27
#define TS_MASK ((1ULL << TS_SHIFT) - 1)
#define TS_DELTA_TEST (~TS_MASK)
int add_timestamp;
};
+/*
+ * Used for the add_timestamp
+ * NONE
+ * EXTEND - wants a time extend
+ * ABSOLUTE - the buffer requests all events to have absolute time stamps
+ * FORCE - force a full time stamp.
+ */
+enum {
+ RB_ADD_STAMP_NONE = 0,
+ RB_ADD_STAMP_EXTEND = BIT(1),
+ RB_ADD_STAMP_ABSOLUTE = BIT(2),
+ RB_ADD_STAMP_FORCE = BIT(3)
+};
/*
* Used for which event context the event is in.
* NMI = 0
RB_CTX_MAX
};
+#if BITS_PER_LONG == 32
+#define RB_TIME_32
+#endif
+
+/* To test on 64 bit machines */
+//#define RB_TIME_32
+
+#ifdef RB_TIME_32
+
+struct rb_time_struct {
+ local_t cnt;
+ local_t top;
+ local_t bottom;
+};
+#else
+#include <asm/local64.h>
+struct rb_time_struct {
+ local64_t time;
+};
+#endif
+typedef struct rb_time_struct rb_time_t;
+
/*
* head_page == tail_page && head == tail then buffer is empty.
*/
size_t shortest_full;
unsigned long read;
unsigned long read_bytes;
- u64 write_stamp;
+ rb_time_t write_stamp;
+ rb_time_t before_stamp;
u64 read_stamp;
/* ring buffer pages to update, > 0 to add, < 0 to remove */
long nr_pages_to_update;
int missed_events;
};
+#ifdef RB_TIME_32
+
+/*
+ * On 32 bit machines, local64_t is very expensive. As the ring
+ * buffer doesn't need all the features of a true 64 bit atomic,
+ * on 32 bit, it uses these functions (64 still uses local64_t).
+ *
+ * For the ring buffer, 64 bit required operations for the time is
+ * the following:
+ *
+ * - Only need 59 bits (uses 60 to make it even).
+ * - Reads may fail if it interrupted a modification of the time stamp.
+ * It will succeed if it did not interrupt another write even if
+ * the read itself is interrupted by a write.
+ * It returns whether it was successful or not.
+ *
+ * - Writes always succeed and will overwrite other writes and writes
+ * that were done by events interrupting the current write.
+ *
+ * - A write followed by a read of the same time stamp will always succeed,
+ * but may not contain the same value.
+ *
+ * - A cmpxchg will fail if it interrupted another write or cmpxchg.
+ * Other than that, it acts like a normal cmpxchg.
+ *
+ * The 60 bit time stamp is broken up by 30 bits in a top and bottom half
+ * (bottom being the least significant 30 bits of the 60 bit time stamp).
+ *
+ * The two most significant bits of each half holds a 2 bit counter (0-3).
+ * Each update will increment this counter by one.
+ * When reading the top and bottom, if the two counter bits match then the
+ * top and bottom together make a valid 60 bit number.
+ */
+#define RB_TIME_SHIFT 30
+#define RB_TIME_VAL_MASK ((1 << RB_TIME_SHIFT) - 1)
+
+static inline int rb_time_cnt(unsigned long val)
+{
+ return (val >> RB_TIME_SHIFT) & 3;
+}
+
+static inline u64 rb_time_val(unsigned long top, unsigned long bottom)
+{
+ u64 val;
+
+ val = top & RB_TIME_VAL_MASK;
+ val <<= RB_TIME_SHIFT;
+ val |= bottom & RB_TIME_VAL_MASK;
+
+ return val;
+}
+
+static inline bool __rb_time_read(rb_time_t *t, u64 *ret, unsigned long *cnt)
+{
+ unsigned long top, bottom;
+ unsigned long c;
+
+ /*
+ * If the read is interrupted by a write, then the cnt will
+ * be different. Loop until both top and bottom have been read
+ * without interruption.
+ */
+ do {
+ c = local_read(&t->cnt);
+ top = local_read(&t->top);
+ bottom = local_read(&t->bottom);
+ } while (c != local_read(&t->cnt));
+
+ *cnt = rb_time_cnt(top);
+
+ /* If top and bottom counts don't match, this interrupted a write */
+ if (*cnt != rb_time_cnt(bottom))
+ return false;
+
+ *ret = rb_time_val(top, bottom);
+ return true;
+}
+
+static bool rb_time_read(rb_time_t *t, u64 *ret)
+{
+ unsigned long cnt;
+
+ return __rb_time_read(t, ret, &cnt);
+}
+
+static inline unsigned long rb_time_val_cnt(unsigned long val, unsigned long cnt)
+{
+ return (val & RB_TIME_VAL_MASK) | ((cnt & 3) << RB_TIME_SHIFT);
+}
+
+static inline void rb_time_split(u64 val, unsigned long *top, unsigned long *bottom)
+{
+ *top = (unsigned long)((val >> RB_TIME_SHIFT) & RB_TIME_VAL_MASK);
+ *bottom = (unsigned long)(val & RB_TIME_VAL_MASK);
+}
+
+static inline void rb_time_val_set(local_t *t, unsigned long val, unsigned long cnt)
+{
+ val = rb_time_val_cnt(val, cnt);
+ local_set(t, val);
+}
+
+static void rb_time_set(rb_time_t *t, u64 val)
+{
+ unsigned long cnt, top, bottom;
+
+ rb_time_split(val, &top, &bottom);
+
+ /* Writes always succeed with a valid number even if it gets interrupted. */
+ do {
+ cnt = local_inc_return(&t->cnt);
+ rb_time_val_set(&t->top, top, cnt);
+ rb_time_val_set(&t->bottom, bottom, cnt);
+ } while (cnt != local_read(&t->cnt));
+}
+
+static inline bool
+rb_time_read_cmpxchg(local_t *l, unsigned long expect, unsigned long set)
+{
+ unsigned long ret;
+
+ ret = local_cmpxchg(l, expect, set);
+ return ret == expect;
+}
+
+static int rb_time_cmpxchg(rb_time_t *t, u64 expect, u64 set)
+{
+ unsigned long cnt, top, bottom;
+ unsigned long cnt2, top2, bottom2;
+ u64 val;
+
+ /* The cmpxchg always fails if it interrupted an update */
+ if (!__rb_time_read(t, &val, &cnt2))
+ return false;
+
+ if (val != expect)
+ return false;
+
+ cnt = local_read(&t->cnt);
+ if ((cnt & 3) != cnt2)
+ return false;
+
+ cnt2 = cnt + 1;
+
+ rb_time_split(val, &top, &bottom);
+ top = rb_time_val_cnt(top, cnt);
+ bottom = rb_time_val_cnt(bottom, cnt);
+
+ rb_time_split(set, &top2, &bottom2);
+ top2 = rb_time_val_cnt(top2, cnt2);
+ bottom2 = rb_time_val_cnt(bottom2, cnt2);
+
+ if (!rb_time_read_cmpxchg(&t->cnt, cnt, cnt2))
+ return false;
+ if (!rb_time_read_cmpxchg(&t->top, top, top2))
+ return false;
+ if (!rb_time_read_cmpxchg(&t->bottom, bottom, bottom2))
+ return false;
+ return true;
+}
+
+#else /* 64 bits */
+
+/* local64_t always succeeds */
+
+static inline bool rb_time_read(rb_time_t *t, u64 *ret)
+{
+ *ret = local64_read(&t->time);
+ return true;
+}
+static void rb_time_set(rb_time_t *t, u64 val)
+{
+ local64_set(&t->time, val);
+}
+
+static bool rb_time_cmpxchg(rb_time_t *t, u64 expect, u64 set)
+{
+ u64 val;
+ val = local64_cmpxchg(&t->time, expect, set);
+ return val == expect;
+}
+#endif
+
/**
* ring_buffer_nr_pages - get the number of buffer pages in the ring buffer
* @buffer: The ring_buffer to get the number of pages from
unsigned length = info->length;
u64 delta = info->delta;
- /* Only a commit updates the timestamp */
- if (unlikely(!rb_event_is_commit(cpu_buffer, event)))
- delta = 0;
-
/*
* If we need to add a timestamp, then we
* add it to the start of the reserved space.
*/
if (unlikely(info->add_timestamp)) {
- bool abs = ring_buffer_time_stamp_abs(cpu_buffer->buffer);
+ bool abs = info->add_timestamp &
+ (RB_ADD_STAMP_FORCE | RB_ADD_STAMP_ABSOLUTE);
event = rb_add_time_stamp(event, abs ? info->delta : delta, abs);
length -= RB_LEN_TIME_EXTEND;
}
#endif
+static __always_inline bool
+rb_event_is_commit(struct ring_buffer_per_cpu *cpu_buffer,
+ struct ring_buffer_event *event)
+{
+ unsigned long addr = (unsigned long)event;
+ unsigned long index;
+
+ index = rb_event_index(event);
+ addr &= PAGE_MASK;
+
+ return cpu_buffer->commit_page->page == (void *)addr &&
+ rb_commit_index(cpu_buffer) == index;
+}
+
+static u64 rb_time_delta(struct ring_buffer_event *event)
+{
+ switch (event->type_len) {
+ case RINGBUF_TYPE_PADDING:
+ return 0;
+
+ case RINGBUF_TYPE_TIME_EXTEND:
+ return ring_buffer_event_time_stamp(event);
+
+ case RINGBUF_TYPE_TIME_STAMP:
+ return 0;
+
+ case RINGBUF_TYPE_DATA:
+ return event->time_delta;
+ default:
+ return 0;
+ }
+}
+
static inline int
rb_try_to_discard(struct ring_buffer_per_cpu *cpu_buffer,
struct ring_buffer_event *event)
struct buffer_page *bpage;
unsigned long index;
unsigned long addr;
+ u64 write_stamp;
+ u64 delta;
new_index = rb_event_index(event);
old_index = new_index + rb_event_ts_length(event);
bpage = READ_ONCE(cpu_buffer->tail_page);
+ delta = rb_time_delta(event);
+
+ if (!rb_time_read(&cpu_buffer->write_stamp, &write_stamp))
+ return 0;
+
+ /* Make sure the write stamp is read before testing the location */
+ barrier();
+
if (bpage->page == (void *)addr && rb_page_write(bpage) == old_index) {
unsigned long write_mask =
local_read(&bpage->write) & ~RB_WRITE_MASK;
unsigned long event_length = rb_event_length(event);
+
+ /* Something came in, can't discard */
+ if (!rb_time_cmpxchg(&cpu_buffer->write_stamp,
+ write_stamp, write_stamp - delta))
+ return 0;
+
+ /*
+ * If an event were to come in now, it would see that the
+ * write_stamp and the before_stamp are different, and assume
+ * that this event just added itself before updating
+ * the write stamp. The interrupting event will fix the
+ * write stamp for us, and use the before stamp as its delta.
+ */
+
/*
* This is on the tail page. It is possible that
* a write could come in and move the tail page
local_set(&cpu_buffer->commit_page->page->commit,
rb_page_write(cpu_buffer->commit_page));
rb_inc_page(cpu_buffer, &cpu_buffer->commit_page);
- /* Only update the write stamp if the page has an event */
- if (rb_page_write(cpu_buffer->commit_page))
- cpu_buffer->write_stamp =
- cpu_buffer->commit_page->page->time_stamp;
/* add barrier to keep gcc from optimizing too much */
barrier();
}
event->time_delta = 1;
}
-static __always_inline bool
-rb_event_is_commit(struct ring_buffer_per_cpu *cpu_buffer,
- struct ring_buffer_event *event)
-{
- unsigned long addr = (unsigned long)event;
- unsigned long index;
-
- index = rb_event_index(event);
- addr &= PAGE_MASK;
-
- return cpu_buffer->commit_page->page == (void *)addr &&
- rb_commit_index(cpu_buffer) == index;
-}
-
-static __always_inline void
-rb_update_write_stamp(struct ring_buffer_per_cpu *cpu_buffer,
- struct ring_buffer_event *event)
-{
- u64 delta;
-
- /*
- * The event first in the commit queue updates the
- * time stamp.
- */
- if (rb_event_is_commit(cpu_buffer, event)) {
- /*
- * A commit event that is first on a page
- * updates the write timestamp with the page stamp
- */
- if (!rb_event_index(event))
- cpu_buffer->write_stamp =
- cpu_buffer->commit_page->page->time_stamp;
- else if (event->type_len == RINGBUF_TYPE_TIME_EXTEND) {
- delta = ring_buffer_event_time_stamp(event);
- cpu_buffer->write_stamp += delta;
- } else if (event->type_len == RINGBUF_TYPE_TIME_STAMP) {
- delta = ring_buffer_event_time_stamp(event);
- cpu_buffer->write_stamp = delta;
- } else
- cpu_buffer->write_stamp += event->time_delta;
- }
-}
-
static void rb_commit(struct ring_buffer_per_cpu *cpu_buffer,
struct ring_buffer_event *event)
{
local_inc(&cpu_buffer->entries);
- rb_update_write_stamp(cpu_buffer, event);
rb_end_commit(cpu_buffer);
}
EXPORT_SYMBOL_GPL(ring_buffer_unlock_commit);
static noinline void
-rb_handle_timestamp(struct ring_buffer_per_cpu *cpu_buffer,
- struct rb_event_info *info)
+rb_check_timestamp(struct ring_buffer_per_cpu *cpu_buffer,
+ struct rb_event_info *info)
{
+ u64 write_stamp;
+
WARN_ONCE(info->delta > (1ULL << 59),
KERN_WARNING "Delta way too big! %llu ts=%llu write stamp = %llu\n%s",
(unsigned long long)info->delta,
(unsigned long long)info->ts,
- (unsigned long long)cpu_buffer->write_stamp,
+ (unsigned long long)(rb_time_read(&cpu_buffer->write_stamp, &write_stamp) ? write_stamp : 0),
sched_clock_stable() ? "" :
"If you just came from a suspend/resume,\n"
"please switch to the trace global clock:\n"
" echo global > /sys/kernel/debug/tracing/trace_clock\n"
"or add trace_clock=global to the kernel command line\n");
- info->add_timestamp = 1;
}
static struct ring_buffer_event *
{
struct ring_buffer_event *event;
struct buffer_page *tail_page;
- unsigned long tail, write;
+ unsigned long tail, write, w;
+ u64 before, after;
+ bool a_ok;
+ bool b_ok;
+
+ /* Don't let the compiler play games with cpu_buffer->tail_page */
+ tail_page = info->tail_page = READ_ONCE(cpu_buffer->tail_page);
+
+ /*A*/ w = local_read(&tail_page->write) & RB_WRITE_MASK;
+ barrier();
+ b_ok = rb_time_read(&cpu_buffer->before_stamp, &before);
+ a_ok = rb_time_read(&cpu_buffer->write_stamp, &after);
+ barrier();
+ info->ts = rb_time_stamp(cpu_buffer->buffer);
+
+ if (ring_buffer_time_stamp_abs(cpu_buffer->buffer)) {
+ info->delta = info->ts;
+ info->add_timestamp = RB_ADD_STAMP_ABSOLUTE;
+ } else {
+ info->delta = info->ts - after;
+ }
+
+ if (likely(a_ok && b_ok)) {
+ if (unlikely(test_time_stamp(info->delta))) {
+ rb_check_timestamp(cpu_buffer, info);
+ info->add_timestamp |= RB_ADD_STAMP_EXTEND;
+ }
+ }
+
+ /*
+ * If interrupting an event time update, we may need an absolute timestamp.
+ * Don't bother if this is the start of a new page (w == 0).
+ */
+ if (unlikely(!a_ok || !b_ok || (before != after && w)))
+ info->add_timestamp |= RB_ADD_STAMP_FORCE | RB_ADD_STAMP_EXTEND;
/*
* If the time delta since the last event is too big to
if (unlikely(info->add_timestamp))
info->length += RB_LEN_TIME_EXTEND;
- /* Don't let the compiler play games with cpu_buffer->tail_page */
- tail_page = info->tail_page = READ_ONCE(cpu_buffer->tail_page);
- write = local_add_return(info->length, &tail_page->write);
+ /*B*/ rb_time_set(&cpu_buffer->before_stamp, info->ts);
+
+ /*C*/ write = local_add_return(info->length, &tail_page->write);
/* set write to only the index of the write */
write &= RB_WRITE_MASK;
+
tail = write - info->length;
+ /* See if we shot pass the end of this buffer page */
+ if (unlikely(write > BUF_PAGE_SIZE)) {
+ if (tail != w) {
+ /* before and after may now different, fix it up*/
+ b_ok = rb_time_read(&cpu_buffer->before_stamp, &before);
+ a_ok = rb_time_read(&cpu_buffer->write_stamp, &after);
+ if (a_ok && b_ok && before != after)
+ (void)rb_time_cmpxchg(&cpu_buffer->before_stamp, before, after);
+ }
+ return rb_move_tail(cpu_buffer, tail, info);
+ }
+
+ if (likely(tail == w)) {
+ u64 save_before;
+ bool s_ok;
+
+ /* Nothing interrupted us between A and C */
+ /*D*/ rb_time_set(&cpu_buffer->write_stamp, info->ts);
+ barrier();
+ /*E*/ s_ok = rb_time_read(&cpu_buffer->before_stamp, &save_before);
+ RB_WARN_ON(cpu_buffer, !s_ok);
+ if (likely(!(info->add_timestamp &
+ (RB_ADD_STAMP_FORCE | RB_ADD_STAMP_ABSOLUTE))))
+ /* This did not interrupt any time update */
+ info->delta = info->ts - after;
+ else
+ /* Just use full timestamp for inerrupting event */
+ info->delta = info->ts;
+ barrier();
+ if (unlikely(info->ts != save_before)) {
+ /* SLOW PATH - Interrupted between C and E */
+
+ a_ok = rb_time_read(&cpu_buffer->write_stamp, &after);
+ RB_WARN_ON(cpu_buffer, !a_ok);
+
+ /* Write stamp must only go forward */
+ if (save_before > after) {
+ /*
+ * We do not care about the result, only that
+ * it gets updated atomically.
+ */
+ (void)rb_time_cmpxchg(&cpu_buffer->write_stamp, after, save_before);
+ }
+ }
+ } else {
+ u64 ts;
+ /* SLOW PATH - Interrupted between A and C */
+ a_ok = rb_time_read(&cpu_buffer->write_stamp, &after);
+ /* Was interrupted before here, write_stamp must be valid */
+ RB_WARN_ON(cpu_buffer, !a_ok);
+ ts = rb_time_stamp(cpu_buffer->buffer);
+ barrier();
+ /*E*/ if (write == (local_read(&tail_page->write) & RB_WRITE_MASK) &&
+ after < ts) {
+ /* Nothing came after this event between C and E */
+ info->delta = ts - after;
+ (void)rb_time_cmpxchg(&cpu_buffer->write_stamp, after, info->ts);
+ info->ts = ts;
+ } else {
+ /*
+ * Interrupted beween C and E:
+ * Lost the previous events time stamp. Just set the
+ * delta to zero, and this will be the same time as
+ * the event this event interrupted. And the events that
+ * came after this will still be correct (as they would
+ * have built their delta on the previous event.
+ */
+ info->delta = 0;
+ }
+ info->add_timestamp &= ~RB_ADD_STAMP_FORCE;
+ }
+
/*
* If this is the first commit on the page, then it has the same
* timestamp as the page itself.
*/
- if (!tail && !ring_buffer_time_stamp_abs(cpu_buffer->buffer))
+ if (unlikely(!tail && !(info->add_timestamp &
+ (RB_ADD_STAMP_FORCE | RB_ADD_STAMP_ABSOLUTE))))
info->delta = 0;
- /* See if we shot pass the end of this buffer page */
- if (unlikely(write > BUF_PAGE_SIZE))
- return rb_move_tail(cpu_buffer, tail, info);
-
/* We reserved something on the buffer */
event = __rb_page_index(tail_page, tail);
struct ring_buffer_event *event;
struct rb_event_info info;
int nr_loops = 0;
- u64 diff;
rb_start_commit(cpu_buffer);
+ /* The commit page can not change after this */
#ifdef CONFIG_RING_BUFFER_ALLOW_SWAP
/*
info.length = rb_calculate_event_length(length);
again:
- info.add_timestamp = 0;
+ info.add_timestamp = RB_ADD_STAMP_NONE;
info.delta = 0;
/*
if (RB_WARN_ON(cpu_buffer, ++nr_loops > 1000))
goto out_fail;
- info.ts = rb_time_stamp(cpu_buffer->buffer);
- diff = info.ts - cpu_buffer->write_stamp;
-
- /* make sure this diff is calculated here */
- barrier();
-
- if (ring_buffer_time_stamp_abs(buffer)) {
- info.delta = info.ts;
- rb_handle_timestamp(cpu_buffer, &info);
- } else /* Did the write stamp get updated already? */
- if (likely(info.ts >= cpu_buffer->write_stamp)) {
- info.delta = diff;
- if (unlikely(test_time_stamp(info.delta)))
- rb_handle_timestamp(cpu_buffer, &info);
- }
-
event = __rb_reserve_next(cpu_buffer, &info);
if (unlikely(PTR_ERR(event) == -EAGAIN)) {
goto again;
}
- if (!event)
- goto out_fail;
-
- return event;
-
+ if (likely(event))
+ return event;
out_fail:
rb_end_commit(cpu_buffer);
return NULL;
if (rb_try_to_discard(cpu_buffer, event))
goto out;
- /*
- * The commit is still visible by the reader, so we
- * must still update the timestamp.
- */
- rb_update_write_stamp(cpu_buffer, event);
out:
rb_end_commit(cpu_buffer);
cpu_buffer->read = 0;
cpu_buffer->read_bytes = 0;
- cpu_buffer->write_stamp = 0;
- cpu_buffer->read_stamp = 0;
+ rb_time_set(&cpu_buffer->write_stamp, 0);
+ rb_time_set(&cpu_buffer->before_stamp, 0);
cpu_buffer->lost_events = 0;
cpu_buffer->last_overrun = 0;
rb_head_page_activate(cpu_buffer);
}
+/* Must have disabled the cpu buffer then done a synchronize_rcu */
+static void reset_disabled_cpu_buffer(struct ring_buffer_per_cpu *cpu_buffer)
+{
+ unsigned long flags;
+
+ raw_spin_lock_irqsave(&cpu_buffer->reader_lock, flags);
+
+ if (RB_WARN_ON(cpu_buffer, local_read(&cpu_buffer->committing)))
+ goto out;
+
+ arch_spin_lock(&cpu_buffer->lock);
+
+ rb_reset_cpu(cpu_buffer);
+
+ arch_spin_unlock(&cpu_buffer->lock);
+
+ out:
+ raw_spin_unlock_irqrestore(&cpu_buffer->reader_lock, flags);
+}
+
/**
* ring_buffer_reset_cpu - reset a ring buffer per CPU buffer
* @buffer: The ring buffer to reset a per cpu buffer of
void ring_buffer_reset_cpu(struct trace_buffer *buffer, int cpu)
{
struct ring_buffer_per_cpu *cpu_buffer = buffer->buffers[cpu];
- unsigned long flags;
if (!cpumask_test_cpu(cpu, buffer->cpumask))
return;
/* Make sure all commits have finished */
synchronize_rcu();
- raw_spin_lock_irqsave(&cpu_buffer->reader_lock, flags);
+ reset_disabled_cpu_buffer(cpu_buffer);
- if (RB_WARN_ON(cpu_buffer, local_read(&cpu_buffer->committing)))
- goto out;
+ atomic_dec(&cpu_buffer->record_disabled);
+ atomic_dec(&cpu_buffer->resize_disabled);
+}
+EXPORT_SYMBOL_GPL(ring_buffer_reset_cpu);
- arch_spin_lock(&cpu_buffer->lock);
+/**
+ * ring_buffer_reset_cpu - reset a ring buffer per CPU buffer
+ * @buffer: The ring buffer to reset a per cpu buffer of
+ * @cpu: The CPU buffer to be reset
+ */
+void ring_buffer_reset_online_cpus(struct trace_buffer *buffer)
+{
+ struct ring_buffer_per_cpu *cpu_buffer;
+ int cpu;
- rb_reset_cpu(cpu_buffer);
+ for_each_online_buffer_cpu(buffer, cpu) {
+ cpu_buffer = buffer->buffers[cpu];
- arch_spin_unlock(&cpu_buffer->lock);
+ atomic_inc(&cpu_buffer->resize_disabled);
+ atomic_inc(&cpu_buffer->record_disabled);
+ }
- out:
- raw_spin_unlock_irqrestore(&cpu_buffer->reader_lock, flags);
+ /* Make sure all commits have finished */
+ synchronize_rcu();
- atomic_dec(&cpu_buffer->record_disabled);
- atomic_dec(&cpu_buffer->resize_disabled);
+ for_each_online_buffer_cpu(buffer, cpu) {
+ cpu_buffer = buffer->buffers[cpu];
+
+ reset_disabled_cpu_buffer(cpu_buffer);
+
+ atomic_dec(&cpu_buffer->record_disabled);
+ atomic_dec(&cpu_buffer->resize_disabled);
+ }
}
-EXPORT_SYMBOL_GPL(ring_buffer_reset_cpu);
/**
* ring_buffer_reset - reset a ring buffer
*/
void ring_buffer_reset(struct trace_buffer *buffer)
{
+ struct ring_buffer_per_cpu *cpu_buffer;
int cpu;
- for_each_buffer_cpu(buffer, cpu)
- ring_buffer_reset_cpu(buffer, cpu);
+ for_each_buffer_cpu(buffer, cpu) {
+ cpu_buffer = buffer->buffers[cpu];
+
+ atomic_inc(&cpu_buffer->resize_disabled);
+ atomic_inc(&cpu_buffer->record_disabled);
+ }
+
+ /* Make sure all commits have finished */
+ synchronize_rcu();
+
+ for_each_buffer_cpu(buffer, cpu) {
+ cpu_buffer = buffer->buffers[cpu];
+
+ reset_disabled_cpu_buffer(cpu_buffer);
+
+ atomic_dec(&cpu_buffer->record_disabled);
+ atomic_dec(&cpu_buffer->resize_disabled);
+ }
}
EXPORT_SYMBOL_GPL(ring_buffer_reset);
projects / linux-2.6-microblaze.git / blobdiff