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authorLinus Torvalds <torvalds@linux-foundation.org>2010-10-27 18:48:00 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2010-10-27 18:48:00 -0700
commita042e26137d7674ac04b1cd2d5c06b9ebc1ee2d5 (patch)
treec1a7a8bda41b99caa4b4a0fe320fc73278879f7d /kernel
parentf66dd539feb849a3a00f7fac67c026e0935e373a (diff)
parente25804a0327dad954f7d43803178fdef2fd35b4e (diff)
Merge branch 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (50 commits) perf python scripting: Add futex-contention script perf python scripting: Fixup cut'n'paste error in sctop script perf scripting: Shut up 'perf record' final status perf record: Remove newline character from perror() argument perf python scripting: Support fedora 11 (audit 1.7.17) perf python scripting: Improve the syscalls-by-pid script perf python scripting: print the syscall name on sctop perf python scripting: Improve the syscalls-counts script perf python scripting: Improve the failed-syscalls-by-pid script kprobes: Remove redundant text_mutex lock in optimize x86/oprofile: Fix uninitialized variable use in debug printk tracing: Fix 'faild' -> 'failed' typo perf probe: Fix format specified for Dwarf_Off parameter perf trace: Fix detection of script extension perf trace: Use $PERF_EXEC_PATH in canned report scripts perf tools: Document event modifiers perf tools: Remove direct slang.h include perf_events: Fix for transaction recovery in group_sched_in() perf_events: Revert: Fix transaction recovery in group_sched_in() perf, x86: Use NUMA aware allocations for PEBS/BTS/DS allocations ...
Diffstat (limited to 'kernel')
-rw-r--r--kernel/kprobes.c7
-rw-r--r--kernel/perf_event.c94
-rw-r--r--kernel/softirq.c16
-rw-r--r--kernel/trace/ring_buffer.c335
-rw-r--r--kernel/trace/trace.c8
5 files changed, 218 insertions, 242 deletions
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index 56a891914273..99865c33a60d 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -74,7 +74,8 @@ static struct hlist_head kretprobe_inst_table[KPROBE_TABLE_SIZE];
/* NOTE: change this value only with kprobe_mutex held */
static bool kprobes_all_disarmed;
-static DEFINE_MUTEX(kprobe_mutex); /* Protects kprobe_table */
+/* This protects kprobe_table and optimizing_list */
+static DEFINE_MUTEX(kprobe_mutex);
static DEFINE_PER_CPU(struct kprobe *, kprobe_instance) = NULL;
static struct {
spinlock_t lock ____cacheline_aligned_in_smp;
@@ -595,6 +596,7 @@ static __kprobes void try_to_optimize_kprobe(struct kprobe *p)
}
#ifdef CONFIG_SYSCTL
+/* This should be called with kprobe_mutex locked */
static void __kprobes optimize_all_kprobes(void)
{
struct hlist_head *head;
@@ -607,17 +609,16 @@ static void __kprobes optimize_all_kprobes(void)
return;
kprobes_allow_optimization = true;
- mutex_lock(&text_mutex);
for (i = 0; i < KPROBE_TABLE_SIZE; i++) {
head = &kprobe_table[i];
hlist_for_each_entry_rcu(p, node, head, hlist)
if (!kprobe_disabled(p))
optimize_kprobe(p);
}
- mutex_unlock(&text_mutex);
printk(KERN_INFO "Kprobes globally optimized\n");
}
+/* This should be called with kprobe_mutex locked */
static void __kprobes unoptimize_all_kprobes(void)
{
struct hlist_head *head;
diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index f309e8014c78..517d827f4982 100644
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -417,8 +417,8 @@ event_filter_match(struct perf_event *event)
return event->cpu == -1 || event->cpu == smp_processor_id();
}
-static int
-__event_sched_out(struct perf_event *event,
+static void
+event_sched_out(struct perf_event *event,
struct perf_cpu_context *cpuctx,
struct perf_event_context *ctx)
{
@@ -437,13 +437,14 @@ __event_sched_out(struct perf_event *event,
}
if (event->state != PERF_EVENT_STATE_ACTIVE)
- return 0;
+ return;
event->state = PERF_EVENT_STATE_INACTIVE;
if (event->pending_disable) {
event->pending_disable = 0;
event->state = PERF_EVENT_STATE_OFF;
}
+ event->tstamp_stopped = ctx->time;
event->pmu->del(event, 0);
event->oncpu = -1;
@@ -452,19 +453,6 @@ __event_sched_out(struct perf_event *event,
ctx->nr_active--;
if (event->attr.exclusive || !cpuctx->active_oncpu)
cpuctx->exclusive = 0;
- return 1;
-}
-
-static void
-event_sched_out(struct perf_event *event,
- struct perf_cpu_context *cpuctx,
- struct perf_event_context *ctx)
-{
- int ret;
-
- ret = __event_sched_out(event, cpuctx, ctx);
- if (ret)
- event->tstamp_stopped = ctx->time;
}
static void
@@ -664,7 +652,7 @@ retry:
}
static int
-__event_sched_in(struct perf_event *event,
+event_sched_in(struct perf_event *event,
struct perf_cpu_context *cpuctx,
struct perf_event_context *ctx)
{
@@ -684,6 +672,8 @@ __event_sched_in(struct perf_event *event,
return -EAGAIN;
}
+ event->tstamp_running += ctx->time - event->tstamp_stopped;
+
if (!is_software_event(event))
cpuctx->active_oncpu++;
ctx->nr_active++;
@@ -694,35 +684,6 @@ __event_sched_in(struct perf_event *event,
return 0;
}
-static inline int
-event_sched_in(struct perf_event *event,
- struct perf_cpu_context *cpuctx,
- struct perf_event_context *ctx)
-{
- int ret = __event_sched_in(event, cpuctx, ctx);
- if (ret)
- return ret;
- event->tstamp_running += ctx->time - event->tstamp_stopped;
- return 0;
-}
-
-static void
-group_commit_event_sched_in(struct perf_event *group_event,
- struct perf_cpu_context *cpuctx,
- struct perf_event_context *ctx)
-{
- struct perf_event *event;
- u64 now = ctx->time;
-
- group_event->tstamp_running += now - group_event->tstamp_stopped;
- /*
- * Schedule in siblings as one group (if any):
- */
- list_for_each_entry(event, &group_event->sibling_list, group_entry) {
- event->tstamp_running += now - event->tstamp_stopped;
- }
-}
-
static int
group_sched_in(struct perf_event *group_event,
struct perf_cpu_context *cpuctx,
@@ -730,19 +691,15 @@ group_sched_in(struct perf_event *group_event,
{
struct perf_event *event, *partial_group = NULL;
struct pmu *pmu = group_event->pmu;
+ u64 now = ctx->time;
+ bool simulate = false;
if (group_event->state == PERF_EVENT_STATE_OFF)
return 0;
pmu->start_txn(pmu);
- /*
- * use __event_sched_in() to delay updating tstamp_running
- * until the transaction is committed. In case of failure
- * we will keep an unmodified tstamp_running which is a
- * requirement to get correct timing information
- */
- if (__event_sched_in(group_event, cpuctx, ctx)) {
+ if (event_sched_in(group_event, cpuctx, ctx)) {
pmu->cancel_txn(pmu);
return -EAGAIN;
}
@@ -751,31 +708,42 @@ group_sched_in(struct perf_event *group_event,
* Schedule in siblings as one group (if any):
*/
list_for_each_entry(event, &group_event->sibling_list, group_entry) {
- if (__event_sched_in(event, cpuctx, ctx)) {
+ if (event_sched_in(event, cpuctx, ctx)) {
partial_group = event;
goto group_error;
}
}
- if (!pmu->commit_txn(pmu)) {
- /* commit tstamp_running */
- group_commit_event_sched_in(group_event, cpuctx, ctx);
+ if (!pmu->commit_txn(pmu))
return 0;
- }
+
group_error:
/*
* Groups can be scheduled in as one unit only, so undo any
* partial group before returning:
+ * The events up to the failed event are scheduled out normally,
+ * tstamp_stopped will be updated.
*
- * use __event_sched_out() to avoid updating tstamp_stopped
- * because the event never actually ran
+ * The failed events and the remaining siblings need to have
+ * their timings updated as if they had gone thru event_sched_in()
+ * and event_sched_out(). This is required to get consistent timings
+ * across the group. This also takes care of the case where the group
+ * could never be scheduled by ensuring tstamp_stopped is set to mark
+ * the time the event was actually stopped, such that time delta
+ * calculation in update_event_times() is correct.
*/
list_for_each_entry(event, &group_event->sibling_list, group_entry) {
if (event == partial_group)
- break;
- __event_sched_out(event, cpuctx, ctx);
+ simulate = true;
+
+ if (simulate) {
+ event->tstamp_running += now - event->tstamp_stopped;
+ event->tstamp_stopped = now;
+ } else {
+ event_sched_out(event, cpuctx, ctx);
+ }
}
- __event_sched_out(group_event, cpuctx, ctx);
+ event_sched_out(group_event, cpuctx, ctx);
pmu->cancel_txn(pmu);
diff --git a/kernel/softirq.c b/kernel/softirq.c
index f02a9dfa19bc..18f4be0d5fe0 100644
--- a/kernel/softirq.c
+++ b/kernel/softirq.c
@@ -229,18 +229,20 @@ restart:
do {
if (pending & 1) {
+ unsigned int vec_nr = h - softirq_vec;
int prev_count = preempt_count();
- kstat_incr_softirqs_this_cpu(h - softirq_vec);
- trace_softirq_entry(h, softirq_vec);
+ kstat_incr_softirqs_this_cpu(vec_nr);
+
+ trace_softirq_entry(vec_nr);
h->action(h);
- trace_softirq_exit(h, softirq_vec);
+ trace_softirq_exit(vec_nr);
if (unlikely(prev_count != preempt_count())) {
- printk(KERN_ERR "huh, entered softirq %td %s %p"
+ printk(KERN_ERR "huh, entered softirq %u %s %p"
"with preempt_count %08x,"
- " exited with %08x?\n", h - softirq_vec,
- softirq_to_name[h - softirq_vec],
- h->action, prev_count, preempt_count());
+ " exited with %08x?\n", vec_nr,
+ softirq_to_name[vec_nr], h->action,
+ prev_count, preempt_count());
preempt_count() = prev_count;
}
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index c3dab054d18e..9ed509a015d8 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -224,6 +224,9 @@ enum {
RB_LEN_TIME_STAMP = 16,
};
+#define skip_time_extend(event) \
+ ((struct ring_buffer_event *)((char *)event + RB_LEN_TIME_EXTEND))
+
static inline int rb_null_event(struct ring_buffer_event *event)
{
return event->type_len == RINGBUF_TYPE_PADDING && !event->time_delta;
@@ -248,8 +251,12 @@ rb_event_data_length(struct ring_buffer_event *event)
return length + RB_EVNT_HDR_SIZE;
}
-/* inline for ring buffer fast paths */
-static unsigned
+/*
+ * Return the length of the given event. Will return
+ * the length of the time extend if the event is a
+ * time extend.
+ */
+static inline unsigned
rb_event_length(struct ring_buffer_event *event)
{
switch (event->type_len) {
@@ -274,13 +281,41 @@ rb_event_length(struct ring_buffer_event *event)
return 0;
}
+/*
+ * Return total length of time extend and data,
+ * or just the event length for all other events.
+ */
+static inline unsigned
+rb_event_ts_length(struct ring_buffer_event *event)
+{
+ unsigned len = 0;
+
+ if (event->type_len == RINGBUF_TYPE_TIME_EXTEND) {
+ /* time extends include the data event after it */
+ len = RB_LEN_TIME_EXTEND;
+ event = skip_time_extend(event);
+ }
+ return len + rb_event_length(event);
+}
+
/**
* ring_buffer_event_length - return the length of the event
* @event: the event to get the length of
+ *
+ * Returns the size of the data load of a data event.
+ * If the event is something other than a data event, it
+ * returns the size of the event itself. With the exception
+ * of a TIME EXTEND, where it still returns the size of the
+ * data load of the data event after it.
*/
unsigned ring_buffer_event_length(struct ring_buffer_event *event)
{
- unsigned length = rb_event_length(event);
+ unsigned length;
+
+ if (event->type_len == RINGBUF_TYPE_TIME_EXTEND)
+ event = skip_time_extend(event);
+
+ length = rb_event_length(event);
if (event->type_len > RINGBUF_TYPE_DATA_TYPE_LEN_MAX)
return length;
length -= RB_EVNT_HDR_SIZE;
@@ -294,6 +329,8 @@ EXPORT_SYMBOL_GPL(ring_buffer_event_length);
static void *
rb_event_data(struct ring_buffer_event *event)
{
+ if (event->type_len == RINGBUF_TYPE_TIME_EXTEND)
+ event = skip_time_extend(event);
BUG_ON(event->type_len > RINGBUF_TYPE_DATA_TYPE_LEN_MAX);
/* If length is in len field, then array[0] has the data */
if (event->type_len)
@@ -404,9 +441,6 @@ static inline int test_time_stamp(u64 delta)
/* Max payload is BUF_PAGE_SIZE - header (8bytes) */
#define BUF_MAX_DATA_SIZE (BUF_PAGE_SIZE - (sizeof(u32) * 2))
-/* Max number of timestamps that can fit on a page */
-#define RB_TIMESTAMPS_PER_PAGE (BUF_PAGE_SIZE / RB_LEN_TIME_EXTEND)
-
int ring_buffer_print_page_header(struct trace_seq *s)
{
struct buffer_data_page field;
@@ -1546,6 +1580,25 @@ static void rb_inc_iter(struct ring_buffer_iter *iter)
iter->head = 0;
}
+/* Slow path, do not inline */
+static noinline struct ring_buffer_event *
+rb_add_time_stamp(struct ring_buffer_event *event, u64 delta)
+{
+ event->type_len = RINGBUF_TYPE_TIME_EXTEND;
+
+ /* Not the first event on the page? */
+ if (rb_event_index(event)) {
+ event->time_delta = delta & TS_MASK;
+ event->array[0] = delta >> TS_SHIFT;
+ } else {
+ /* nope, just zero it */
+ event->time_delta = 0;
+ event->array[0] = 0;
+ }
+
+ return skip_time_extend(event);
+}
+
/**
* ring_buffer_update_event - update event type and data
* @event: the even to update
@@ -1558,28 +1611,31 @@ static void rb_inc_iter(struct ring_buffer_iter *iter)
* data field.
*/
static void
-rb_update_event(struct ring_buffer_event *event,
- unsigned type, unsigned length)
+rb_update_event(struct ring_buffer_per_cpu *cpu_buffer,
+ struct ring_buffer_event *event, unsigned length,
+ int add_timestamp, u64 delta)
{
- event->type_len = type;
-
- switch (type) {
-
- case RINGBUF_TYPE_PADDING:
- case RINGBUF_TYPE_TIME_EXTEND:
- case RINGBUF_TYPE_TIME_STAMP:
- break;
+ /* Only a commit updates the timestamp */
+ if (unlikely(!rb_event_is_commit(cpu_buffer, event)))
+ delta = 0;
- case 0:
- length -= RB_EVNT_HDR_SIZE;
- if (length > RB_MAX_SMALL_DATA || RB_FORCE_8BYTE_ALIGNMENT)
- event->array[0] = length;
- else
- event->type_len = DIV_ROUND_UP(length, RB_ALIGNMENT);
- break;
- default:
- BUG();
+ /*
+ * If we need to add a timestamp, then we
+ * add it to the start of the resevered space.
+ */
+ if (unlikely(add_timestamp)) {
+ event = rb_add_time_stamp(event, delta);
+ length -= RB_LEN_TIME_EXTEND;
+ delta = 0;
}
+
+ event->time_delta = delta;
+ length -= RB_EVNT_HDR_SIZE;
+ if (length > RB_MAX_SMALL_DATA || RB_FORCE_8BYTE_ALIGNMENT) {
+ event->type_len = 0;
+ event->array[0] = length;
+ } else
+ event->type_len = DIV_ROUND_UP(length, RB_ALIGNMENT);
}
/*
@@ -1823,10 +1879,13 @@ rb_reset_tail(struct ring_buffer_per_cpu *cpu_buffer,
local_sub(length, &tail_page->write);
}
-static struct ring_buffer_event *
+/*
+ * This is the slow path, force gcc not to inline it.
+ */
+static noinline struct ring_buffer_event *
rb_move_tail(struct ring_buffer_per_cpu *cpu_buffer,
unsigned long length, unsigned long tail,
- struct buffer_page *tail_page, u64 *ts)
+ struct buffer_page *tail_page, u64 ts)
{
struct buffer_page *commit_page = cpu_buffer->commit_page;
struct ring_buffer *buffer = cpu_buffer->buffer;
@@ -1909,8 +1968,8 @@ rb_move_tail(struct ring_buffer_per_cpu *cpu_buffer,
* Nested commits always have zero deltas, so
* just reread the time stamp
*/
- *ts = rb_time_stamp(buffer);
- next_page->page->time_stamp = *ts;
+ ts = rb_time_stamp(buffer);
+ next_page->page->time_stamp = ts;
}
out_again:
@@ -1929,12 +1988,21 @@ rb_move_tail(struct ring_buffer_per_cpu *cpu_buffer,
static struct ring_buffer_event *
__rb_reserve_next(struct ring_buffer_per_cpu *cpu_buffer,
- unsigned type, unsigned long length, u64 *ts)
+ unsigned long length, u64 ts,
+ u64 delta, int add_timestamp)
{
struct buffer_page *tail_page;
struct ring_buffer_event *event;
unsigned long tail, write;
+ /*
+ * If the time delta since the last event is too big to
+ * hold in the time field of the event, then we append a
+ * TIME EXTEND event ahead of the data event.
+ */
+ if (unlikely(add_timestamp))
+ length += RB_LEN_TIME_EXTEND;
+
tail_page = cpu_buffer->tail_page;
write = local_add_return(length, &tail_page->write);
@@ -1943,7 +2011,7 @@ __rb_reserve_next(struct ring_buffer_per_cpu *cpu_buffer,
tail = write - length;
/* See if we shot pass the end of this buffer page */
- if (write > BUF_PAGE_SIZE)
+ if (unlikely(write > BUF_PAGE_SIZE))
return rb_move_tail(cpu_buffer, length, tail,
tail_page, ts);
@@ -1951,18 +2019,16 @@ __rb_reserve_next(struct ring_buffer_per_cpu *cpu_buffer,
event = __rb_page_index(tail_page, tail);
kmemcheck_annotate_bitfield(event, bitfield);
- rb_update_event(event, type, length);
+ rb_update_event(cpu_buffer, event, length, add_timestamp, delta);
- /* The passed in type is zero for DATA */
- if (likely(!type))
- local_inc(&tail_page->entries);
+ local_inc(&tail_page->entries);
/*
* If this is the first commit on the page, then update
* its timestamp.
*/
if (!tail)
- tail_page->page->time_stamp = *ts;
+ tail_page->page->time_stamp = ts;
return event;
}
@@ -1977,7 +2043,7 @@ rb_try_to_discard(struct ring_buffer_per_cpu *cpu_buffer,
unsigned long addr;
new_index = rb_event_index(event);
- old_index = new_index + rb_event_length(event);
+ old_index = new_index + rb_event_ts_length(event);
addr = (unsigned long)event;
addr &= PAGE_MASK;
@@ -2003,76 +2069,13 @@ rb_try_to_discard(struct ring_buffer_per_cpu *cpu_buffer,
return 0;
}
-static int
-rb_add_time_stamp(struct ring_buffer_per_cpu *cpu_buffer,
- u64 *ts, u64 *delta)
-{
- struct ring_buffer_event *event;
- int ret;
-
- WARN_ONCE(*delta > (1ULL << 59),
- KERN_WARNING "Delta way too big! %llu ts=%llu write stamp = %llu\n",
- (unsigned long long)*delta,
- (unsigned long long)*ts,
- (unsigned long long)cpu_buffer->write_stamp);
-
- /*
- * The delta is too big, we to add a
- * new timestamp.
- */
- event = __rb_reserve_next(cpu_buffer,
- RINGBUF_TYPE_TIME_EXTEND,
- RB_LEN_TIME_EXTEND,
- ts);
- if (!event)
- return -EBUSY;
-
- if (PTR_ERR(event) == -EAGAIN)
- return -EAGAIN;
-
- /* Only a commited time event can update the write stamp */
- if (rb_event_is_commit(cpu_buffer, event)) {
- /*
- * If this is the first on the page, then it was
- * updated with the page itself. Try to discard it
- * and if we can't just make it zero.
- */
- if (rb_event_index(event)) {
- event->time_delta = *delta & TS_MASK;
- event->array[0] = *delta >> TS_SHIFT;
- } else {
- /* try to discard, since we do not need this */
- if (!rb_try_to_discard(cpu_buffer, event)) {
- /* nope, just zero it */
- event->time_delta = 0;
- event->array[0] = 0;
- }
- }
- cpu_buffer->write_stamp = *ts;
- /* let the caller know this was the commit */
- ret = 1;
- } else {
- /* Try to discard the event */
- if (!rb_try_to_discard(cpu_buffer, event)) {
- /* Darn, this is just wasted space */
- event->time_delta = 0;
- event->array[0] = 0;
- }
- ret = 0;
- }
-
- *delta = 0;
-
- return ret;
-}
-
static void rb_start_commit(struct ring_buffer_per_cpu *cpu_buffer)
{
local_inc(&cpu_buffer->committing);
local_inc(&cpu_buffer->commits);
}
-static void rb_end_commit(struct ring_buffer_per_cpu *cpu_buffer)
+static inline void rb_end_commit(struct ring_buffer_per_cpu *cpu_buffer)
{
unsigned long commits;
@@ -2110,9 +2113,10 @@ rb_reserve_next_event(struct ring_buffer *buffer,
unsigned long length)
{
struct ring_buffer_event *event;
- u64 ts, delta = 0;
- int commit = 0;
+ u64 ts, delta;
int nr_loops = 0;
+ int add_timestamp;
+ u64 diff;
rb_start_commit(cpu_buffer);
@@ -2133,6 +2137,9 @@ rb_reserve_next_event(struct ring_buffer *buffer,
length = rb_calculate_event_length(length);
again:
+ add_timestamp = 0;
+ delta = 0;
+
/*
* We allow for interrupts to reenter here and do a trace.
* If one does, it will cause this original code to loop
@@ -2146,56 +2153,32 @@ rb_reserve_next_event(struct ring_buffer *buffer,
goto out_fail;
ts = rb_time_stamp(cpu_buffer->buffer);
+ diff = ts - cpu_buffer->write_stamp;
- /*
- * Only the first commit can update the timestamp.
- * Yes there is a race here. If an interrupt comes in
- * just after the conditional and it traces too, then it
- * will also check the deltas. More than one timestamp may
- * also be made. But only the entry that did the actual
- * commit will be something other than zero.
- */
- if (likely(cpu_buffer->tail_page == cpu_buffer->commit_page &&
- rb_page_write(cpu_buffer->tail_page) ==
- rb_commit_index(cpu_buffer))) {
- u64 diff;
-
- diff = ts - cpu_buffer->write_stamp;
-
- /* make sure this diff is calculated here */
- barrier();
-
- /* Did the write stamp get updated already? */
- if (unlikely(ts < cpu_buffer->write_stamp))
- goto get_event;
+ /* make sure this diff is calculated here */
+ barrier();
+ /* Did the write stamp get updated already? */
+ if (likely(ts >= cpu_buffer->write_stamp)) {
delta = diff;
if (unlikely(test_time_stamp(delta))) {
-
- commit = rb_add_time_stamp(cpu_buffer, &ts, &delta);
- if (commit == -EBUSY)
- goto out_fail;
-
- if (commit == -EAGAIN)
- goto again;
-
- RB_WARN_ON(cpu_buffer, commit < 0);
+ WARN_ONCE(delta > (1ULL << 59),
+ KERN_WARNING "Delta way too big! %llu ts=%llu write stamp = %llu\n",
+ (unsigned long long)delta,
+ (unsigned long long)ts,
+ (unsigned long long)cpu_buffer->write_stamp);
+ add_timestamp = 1;
}
}
- get_event:
- event = __rb_reserve_next(cpu_buffer, 0, length, &ts);
+ event = __rb_reserve_next(cpu_buffer, length, ts,
+ delta, add_timestamp);
if (unlikely(PTR_ERR(event) == -EAGAIN))
goto again;
if (!event)
goto out_fail;
- if (!rb_event_is_commit(cpu_buffer, event))
- delta = 0;
-
- event->time_delta = delta;
-
return event;
out_fail:
@@ -2207,13 +2190,9 @@ rb_reserve_next_event(struct ring_buffer *buffer,
#define TRACE_RECURSIVE_DEPTH 16
-static int trace_recursive_lock(void)
+/* Keep this code out of the fast path cache */
+static noinline void trace_recursive_fail(void)
{
- current->trace_recursion++;
-
- if (likely(current->trace_recursion < TRACE_RECURSIVE_DEPTH))
- return 0;
-
/* Disable all tracing before we do anything else */
tracing_off_permanent();
@@ -2225,10 +2204,21 @@ static int trace_recursive_lock(void)
in_nmi());
WARN_ON_ONCE(1);
+}
+
+static inline int trace_recursive_lock(void)
+{
+ current->trace_recursion++;
+
+ if (likely(current->trace_recursion < TRACE_RECURSIVE_DEPTH))
+ return 0;
+
+ trace_recursive_fail();
+
return -1;
}
-static void trace_recursive_unlock(void)
+static inline void trace_recursive_unlock(void)
{
WARN_ON_ONCE(!current->trace_recursion);
@@ -2308,12 +2298,28 @@ static 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))
- cpu_buffer->write_stamp += event->time_delta;
+ 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 = event->array[0];
+ delta <<= TS_SHIFT;
+ delta += event->time_delta;
+ cpu_buffer->write_stamp += delta;
+ } else
+ cpu_buffer->write_stamp += event->time_delta;
+ }
}
static void rb_commit(struct ring_buffer_per_cpu *cpu_buffer,
@@ -2353,6 +2359,9 @@ EXPORT_SYMBOL_GPL(ring_buffer_unlock_commit);
static inline void rb_event_discard(struct ring_buffer_event *event)
{
+ if (event->type_len == RINGBUF_TYPE_TIME_EXTEND)
+ event = skip_time_extend(event);
+
/* array[0] holds the actual length for the discarded event */
event->array[0] = rb_event_data_length(event) - RB_EVNT_HDR_SIZE;
event->type_len = RINGBUF_TYPE_PADDING;
@@ -3049,12 +3058,12 @@ rb_buffer_peek(struct ring_buffer_per_cpu *cpu_buffer, u64 *ts,
again:
/*
- * We repeat when a timestamp is encountered. It is possible
- * to get multiple timestamps from an interrupt entering just
- * as one timestamp is about to be written, or from discarded
- * commits. The most that we can have is the number on a single page.
+ * We repeat when a time extend is encountered.
+ * Since the time extend is always attached to a data event,
+ * we should never loop more than once.
+ * (We never hit the following condition more than twice).
*/
- if (RB_WARN_ON(cpu_buffer, ++nr_loops > RB_TIMESTAMPS_PER_PAGE))
+ if (RB_WARN_ON(cpu_buffer, ++nr_loops > 2))
return NULL;
reader = rb_get_reader_page(cpu_buffer);
@@ -3130,14 +3139,12 @@ rb_iter_peek(struct ring_buffer_iter *iter, u64 *ts)
return NULL;
/*
- * We repeat when a timestamp is encountered.
- * We can get multiple timestamps by nested interrupts or also
- * if filtering is on (discarding commits). Since discarding
- * commits can be frequent we can get a lot of timestamps.
- * But we limit them by not adding timestamps if they begin
- * at the start of a page.
+ * We repeat when a time extend is encountered.
+ * Since the time extend is always attached to a data event,
+ * we should never loop more than once.
+ * (We never hit the following condition more than twice).
*/
- if (RB_WARN_ON(cpu_buffer, ++nr_loops > RB_TIMESTAMPS_PER_PAGE))
+ if (RB_WARN_ON(cpu_buffer, ++nr_loops > 2))
return NULL;
if (rb_per_cpu_empty(cpu_buffer))
@@ -3835,7 +3842,8 @@ int ring_buffer_read_page(struct ring_buffer *buffer,
if (len > (commit - read))
len = (commit - read);
- size = rb_event_length(event);
+ /* Always keep the time extend and data together */
+ size = rb_event_ts_length(event);
if (len < size)
goto out_unlock;
@@ -3857,7 +3865,8 @@ int ring_buffer_read_page(struct ring_buffer *buffer,
break;
event = rb_reader_event(cpu_buffer);
- size = rb_event_length(event);
+ /* Always keep the time extend and data together */
+ size = rb_event_ts_length(event);
} while (len > size);
/* update bpage */
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 001bcd2ccf4a..82d9b8106cd0 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -3996,13 +3996,9 @@ static void tracing_init_debugfs_percpu(long cpu)
{
struct dentry *d_percpu = tracing_dentry_percpu();
struct dentry *d_cpu;
- /* strlen(cpu) + MAX(log10(cpu)) + '\0' */
- char cpu_dir[7];
+ char cpu_dir[30]; /* 30 characters should be more than enough */
- if (cpu > 999 || cpu < 0)
- return;
-
- sprintf(cpu_dir, "cpu%ld", cpu);
+ snprintf(cpu_dir, 30, "cpu%ld", cpu);
d_cpu = debugfs_create_dir(cpu_dir, d_percpu);
if (!d_cpu) {
pr_warning("Could not create debugfs '%s' entry\n", cpu_dir);

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