Merge tag 'trace-v4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing update from Steven Rostedt:
 "Mostly this is just clean ups and micro optimizations.

  The changes with more meat are:

   - Allowing the trace event filters to filter on CPU number and
     process ids

   - Two new markers for trace output latency were added (10 and 100
     msec latencies)

   - Have tracing_thresh filter function profiling time

  I also worked on modifying the ring buffer code for some future work,
  and moved the adding of the timestamp around.  One of my changes
  caused a regression, and since other changes were built on top of it
  and already tested, I had to operate a revert of that change.  Instead
  of rebasing, this change set has the code that caused a regression as
  well as the code to revert that change without touching the other
  changes that were made on top of it"

* tag 'trace-v4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  ring-buffer: Revert "ring-buffer: Get timestamp after event is allocated"
  tracing: Don't make assumptions about length of string on task rename
  tracing: Allow triggers to filter for CPU ids and process names
  ftrace: Format MCOUNT_ADDR address as type unsigned long
  tracing: Introduce two additional marks for delay
  ftrace: Fix function_graph duration spacing with 7-digits
  ftrace: add tracing_thresh to function profile
  tracing: Clean up stack tracing and fix fentry updates
  ring-buffer: Reorganize function locations
  ring-buffer: Make sure event has enough room for extend and padding
  ring-buffer: Get timestamp after event is allocated
  ring-buffer: Move the adding of the extended timestamp out of line
  ring-buffer: Add event descriptor to simplify passing data
  ftrace: correct the counter increment for trace_buffer data
  tracing: Fix for non-continuous cpu ids
  tracing: Prefer kcalloc over kzalloc with multiply

Documentation/trace/ftrace.txt

@@ -691,6 +691,8 @@ The above is mostly meaningful for kernel developers.
 	 The marks are determined by the difference between this
 	 current trace and the next trace.
 	  '$' - greater than 1 second
+	  '@' - greater than 100 milisecond
+	  '*' - greater than 10 milisecond
 	  '#' - greater than 1000 microsecond
 	  '!' - greater than 100 microsecond
 	  '+' - greater than 10 microsecond
@@ -1944,26 +1946,49 @@ want, depending on your needs.
 
   ie:
 
-  0)               |    up_write() {
-  0)   0.646 us    |      _spin_lock_irqsave();
-  0)   0.684 us    |      _spin_unlock_irqrestore();
-  0)   3.123 us    |    }
-  0)   0.548 us    |    fput();
-  0) + 58.628 us   |  }
+  3) # 1837.709 us |          } /* __switch_to */
+  3)               |          finish_task_switch() {
+  3)   0.313 us    |            _raw_spin_unlock_irq();
+  3)   3.177 us    |          }
+  3) # 1889.063 us |        } /* __schedule */
+  3) ! 140.417 us  |      } /* __schedule */
+  3) # 2034.948 us |    } /* schedule */
+  3) * 33998.59 us |  } /* schedule_preempt_disabled */
 
   [...]
 
-  0)               |      putname() {
-  0)               |        kmem_cache_free() {
-  0)   0.518 us    |          __phys_addr();
-  0)   1.757 us    |        }
-  0)   2.861 us    |      }
-  0) ! 115.305 us  |    }
-  0) ! 116.402 us  |  }
+  1)   0.260 us    |              msecs_to_jiffies();
+  1)   0.313 us    |              __rcu_read_unlock();
+  1) + 61.770 us   |            }
+  1) + 64.479 us   |          }
+  1)   0.313 us    |          rcu_bh_qs();
+  1)   0.313 us    |          __local_bh_enable();
+  1) ! 217.240 us  |        }
+  1)   0.365 us    |        idle_cpu();
+  1)               |        rcu_irq_exit() {
+  1)   0.417 us    |          rcu_eqs_enter_common.isra.47();
+  1)   3.125 us    |        }
+  1) ! 227.812 us  |      }
+  1) ! 457.395 us  |    }
+  1) @ 119760.2 us |  }
+
+  [...]
+
+  2)               |    handle_IPI() {
+  1)   6.979 us    |                  }
+  2)   0.417 us    |      scheduler_ipi();
+  1)   9.791 us    |                }
+  1) + 12.917 us   |              }
+  2)   3.490 us    |    }
+  1) + 15.729 us   |            }
+  1) + 18.542 us   |          }
+  2) $ 3594274 us  |  }
 
   + means that the function exceeded 10 usecs.
   ! means that the function exceeded 100 usecs.
   # means that the function exceeded 1000 usecs.
+  * means that the function exceeded 10 msecs.
+  @ means that the function exceeded 100 msecs.
   $ means that the function exceeded 1 sec.
 
 

arch/metag/include/asm/ftrace.h

@@ -6,7 +6,7 @@
 
 #ifndef __ASSEMBLY__
 extern void mcount_wrapper(void);
-#define MCOUNT_ADDR		((long)(mcount_wrapper))
+#define MCOUNT_ADDR		((unsigned long)(mcount_wrapper))
 
 static inline unsigned long ftrace_call_adjust(unsigned long addr)
 {

arch/microblaze/include/asm/ftrace.h

@@ -3,7 +3,7 @@
 
 #ifdef CONFIG_FUNCTION_TRACER
 
-#define MCOUNT_ADDR		((long)(_mcount))
+#define MCOUNT_ADDR		((unsigned long)(_mcount))
 #define MCOUNT_INSN_SIZE	8 /* sizeof mcount call */
 
 #ifndef __ASSEMBLY__

arch/powerpc/include/asm/ftrace.h

@@ -2,7 +2,7 @@
 #define _ASM_POWERPC_FTRACE
 
 #ifdef CONFIG_FUNCTION_TRACER
-#define MCOUNT_ADDR		((long)(_mcount))
+#define MCOUNT_ADDR		((unsigned long)(_mcount))
 #define MCOUNT_INSN_SIZE	4 /* sizeof mcount call */
 
 #ifdef __ASSEMBLY__

arch/sh/include/asm/ftrace.h

@@ -9,7 +9,7 @@
 #ifndef __ASSEMBLY__
 extern void mcount(void);
 
-#define MCOUNT_ADDR		((long)(mcount))
+#define MCOUNT_ADDR		((unsigned long)(mcount))
 
 #ifdef CONFIG_DYNAMIC_FTRACE
 #define CALL_ADDR		((long)(ftrace_call))

arch/sparc/include/asm/ftrace.h

@@ -2,7 +2,7 @@
 #define _ASM_SPARC64_FTRACE
 
 #ifdef CONFIG_MCOUNT
-#define MCOUNT_ADDR		((long)(_mcount))
+#define MCOUNT_ADDR		((unsigned long)(_mcount))
 #define MCOUNT_INSN_SIZE	4 /* sizeof mcount call */
 
 #ifndef __ASSEMBLY__

arch/x86/include/asm/ftrace.h

@@ -3,9 +3,9 @@
 
 #ifdef CONFIG_FUNCTION_TRACER
 #ifdef CC_USING_FENTRY
-# define MCOUNT_ADDR		((long)(__fentry__))
+# define MCOUNT_ADDR		((unsigned long)(__fentry__))
 #else
-# define MCOUNT_ADDR		((long)(mcount))
+# define MCOUNT_ADDR		((unsigned long)(mcount))
 #endif
 #define MCOUNT_INSN_SIZE	5 /* sizeof mcount call */
 

include/trace/events/task.h

@@ -46,7 +46,7 @@ TRACE_EVENT(task_rename,
 	TP_fast_assign(
 		__entry->pid = task->pid;
 		memcpy(entry->oldcomm, task->comm, TASK_COMM_LEN);
-		memcpy(entry->newcomm, comm, TASK_COMM_LEN);
+		strlcpy(entry->newcomm, comm, TASK_COMM_LEN);
 		__entry->oom_score_adj = task->signal->oom_score_adj;
 	),
 

kernel/trace/ftrace.c

@@ -630,13 +630,18 @@ static int function_stat_show(struct seq_file *m, void *v)
 		goto out;
 	}
 
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+	avg = rec->time;
+	do_div(avg, rec->counter);
+	if (tracing_thresh && (avg < tracing_thresh))
+		goto out;
+#endif
+
 	kallsyms_lookup(rec->ip, NULL, NULL, NULL, str);
 	seq_printf(m, "  %-30.30s  %10lu", str, rec->counter);
 
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 	seq_puts(m, "    ");
-	avg = rec->time;
-	do_div(avg, rec->counter);
 
 	/* Sample standard deviation (s^2) */
 	if (rec->counter <= 1)

kernel/trace/trace.c

@@ -3035,7 +3035,7 @@ __tracing_open(struct inode *inode, struct file *file, bool snapshot)
 	if (!iter)
 		return ERR_PTR(-ENOMEM);
 
-	iter->buffer_iter = kzalloc(sizeof(*iter->buffer_iter) * num_possible_cpus(),
+	iter->buffer_iter = kcalloc(nr_cpu_ids, sizeof(*iter->buffer_iter),
 				    GFP_KERNEL);
 	if (!iter->buffer_iter)
 		goto release;
@@ -6990,7 +6990,7 @@ void ftrace_dump(enum ftrace_dump_mode oops_dump_mode)
 	trace_init_global_iter(&iter);
 
 	for_each_tracing_cpu(cpu) {
-		atomic_inc(&per_cpu_ptr(iter.tr->trace_buffer.data, cpu)->disabled);
+		atomic_inc(&per_cpu_ptr(iter.trace_buffer->data, cpu)->disabled);
 	}
 
 	old_userobj = trace_flags & TRACE_ITER_SYM_USEROBJ;

kernel/trace/trace_events.c

@@ -30,6 +30,7 @@
 DEFINE_MUTEX(event_mutex);
 
 LIST_HEAD(ftrace_events);
+static LIST_HEAD(ftrace_generic_fields);
 static LIST_HEAD(ftrace_common_fields);
 
 #define GFP_TRACE (GFP_KERNEL | __GFP_ZERO)
@@ -94,6 +95,10 @@ trace_find_event_field(struct trace_event_call *call, char *name)
 	struct ftrace_event_field *field;
 	struct list_head *head;
 
+	field = __find_event_field(&ftrace_generic_fields, name);
+	if (field)
+		return field;
+
 	field = __find_event_field(&ftrace_common_fields, name);
 	if (field)
 		return field;
@@ -144,6 +149,13 @@ int trace_define_field(struct trace_event_call *call, const char *type,
 }
 EXPORT_SYMBOL_GPL(trace_define_field);
 
+#define __generic_field(type, item, filter_type)			\
+	ret = __trace_define_field(&ftrace_generic_fields, #type,	\
+				   #item, 0, 0, is_signed_type(type),	\
+				   filter_type);			\
+	if (ret)							\
+		return ret;
+
 #define __common_field(type, item)					\
 	ret = __trace_define_field(&ftrace_common_fields, #type,	\
 				   "common_" #item,			\
@@ -153,6 +165,16 @@ EXPORT_SYMBOL_GPL(trace_define_field);
 	if (ret)							\
 		return ret;
 
+static int trace_define_generic_fields(void)
+{
+	int ret;
+
+	__generic_field(int, cpu, FILTER_OTHER);
+	__generic_field(char *, comm, FILTER_PTR_STRING);
+
+	return ret;
+}
+
 static int trace_define_common_fields(void)
 {
 	int ret;
@@ -2671,6 +2693,9 @@ static __init int event_trace_init(void)
 	if (!entry)
 		pr_warn("Could not create tracefs 'available_events' entry\n");
 
+	if (trace_define_generic_fields())
+		pr_warn("tracing: Failed to allocated generic fields");
+
 	if (trace_define_common_fields())
 		pr_warn("tracing: Failed to allocate common fields");
 

kernel/trace/trace_events_filter.c

@@ -252,6 +252,50 @@ static int filter_pred_strloc(struct filter_pred *pred, void *event)
 	return match;
 }
 
+/* Filter predicate for CPUs. */
+static int filter_pred_cpu(struct filter_pred *pred, void *event)
+{
+	int cpu, cmp;
+	int match = 0;
+
+	cpu = raw_smp_processor_id();
+	cmp = pred->val;
+
+	switch (pred->op) {
+	case OP_EQ:
+		match = cpu == cmp;
+		break;
+	case OP_LT:
+		match = cpu < cmp;
+		break;
+	case OP_LE:
+		match = cpu <= cmp;
+		break;
+	case OP_GT:
+		match = cpu > cmp;
+		break;
+	case OP_GE:
+		match = cpu >= cmp;
+		break;
+	default:
+		break;
+	}
+
+	return !!match == !pred->not;
+}
+
+/* Filter predicate for COMM. */
+static int filter_pred_comm(struct filter_pred *pred, void *event)
+{
+	int cmp, match;
+
+	cmp = pred->regex.match(current->comm, &pred->regex,
+				pred->regex.field_len);
+	match = cmp ^ pred->not;
+
+	return match;
+}
+
 static int filter_pred_none(struct filter_pred *pred, void *event)
 {
 	return 0;
@@ -1002,7 +1046,10 @@ static int init_pred(struct filter_parse_state *ps,
 	if (is_string_field(field)) {
 		filter_build_regex(pred);
 
-		if (field->filter_type == FILTER_STATIC_STRING) {
+		if (!strcmp(field->name, "comm")) {
+			fn = filter_pred_comm;
+			pred->regex.field_len = TASK_COMM_LEN;
+		} else if (field->filter_type == FILTER_STATIC_STRING) {
 			fn = filter_pred_string;
 			pred->regex.field_len = field->size;
 		} else if (field->filter_type == FILTER_DYN_STRING)
@@ -1025,6 +1072,9 @@ static int init_pred(struct filter_parse_state *ps,
 		}
 		pred->val = val;
 
+		if (!strcmp(field->name, "cpu"))
+			fn = filter_pred_cpu;
+		else
 			fn = select_comparison_fn(pred->op, field->size,
 					  field->is_signed);
 		if (!fn) {

kernel/trace/trace_functions_graph.c

@@ -715,13 +715,13 @@ trace_print_graph_duration(unsigned long long duration, struct trace_seq *s)
 
 		snprintf(nsecs_str, slen, "%03lu", nsecs_rem);
 		trace_seq_printf(s, ".%s", nsecs_str);
-		len += strlen(nsecs_str);
+		len += strlen(nsecs_str) + 1;
 	}
 
 	trace_seq_puts(s, " us ");
 
 	/* Print remaining spaces to fit the row's width */
-	for (i = len; i < 7; i++)
+	for (i = len; i < 8; i++)
 		trace_seq_putc(s, ' ');
 }
 

kernel/trace/trace_output.c

@@ -496,6 +496,8 @@ static const struct trace_mark {
 	char			sym;
 } mark[] = {
 	MARK(1000000000ULL	, '$'), /* 1 sec */
+	MARK(100000000ULL	, '@'), /* 100 msec */
+	MARK(10000000ULL	, '*'), /* 10 msec */
 	MARK(1000000ULL		, '#'), /* 1000 usecs */
 	MARK(100000ULL		, '!'), /* 100 usecs */
 	MARK(10000ULL		, '+'), /* 10 usecs */
@@ -508,7 +510,7 @@ char trace_find_mark(unsigned long long d)
 	int size = ARRAY_SIZE(mark);
 
 	for (i = 0; i < size; i++) {
-		if (d >= mark[i].val)
+		if (d > mark[i].val)
 			break;
 	}
 

kernel/trace/trace_stack.c

@@ -18,12 +18,6 @@
 
 #define STACK_TRACE_ENTRIES 500
 
-#ifdef CC_USING_FENTRY
-# define fentry		1
-#else
-# define fentry		0
-#endif
-
 static unsigned long stack_dump_trace[STACK_TRACE_ENTRIES+1] =
 	 { [0 ... (STACK_TRACE_ENTRIES)] = ULONG_MAX };
 static unsigned stack_dump_index[STACK_TRACE_ENTRIES];
@@ -35,7 +29,7 @@ static unsigned stack_dump_index[STACK_TRACE_ENTRIES];
  */
 static struct stack_trace max_stack_trace = {
 	.max_entries		= STACK_TRACE_ENTRIES - 1,
-	.entries		= &stack_dump_trace[1],
+	.entries		= &stack_dump_trace[0],
 };
 
 static unsigned long max_stack_size;
@@ -55,7 +49,7 @@ static inline void print_max_stack(void)
 
 	pr_emerg("        Depth    Size   Location    (%d entries)\n"
 			   "        -----    ----   --------\n",
-			   max_stack_trace.nr_entries - 1);
+			   max_stack_trace.nr_entries);
 
 	for (i = 0; i < max_stack_trace.nr_entries; i++) {
 		if (stack_dump_trace[i] == ULONG_MAX)
@@ -77,7 +71,7 @@ check_stack(unsigned long ip, unsigned long *stack)
 	unsigned long this_size, flags; unsigned long *p, *top, *start;
 	static int tracer_frame;
 	int frame_size = ACCESS_ONCE(tracer_frame);
-	int i;
+	int i, x;
 
 	this_size = ((unsigned long)stack) & (THREAD_SIZE-1);
 	this_size = THREAD_SIZE - this_size;
@@ -105,26 +99,20 @@ check_stack(unsigned long ip, unsigned long *stack)
 	max_stack_size = this_size;
 
 	max_stack_trace.nr_entries = 0;
-
-	if (using_ftrace_ops_list_func())
-		max_stack_trace.skip = 4;
-	else
 	max_stack_trace.skip = 3;
 
 	save_stack_trace(&max_stack_trace);
 
-	/*
-	 * Add the passed in ip from the function tracer.
-	 * Searching for this on the stack will skip over
-	 * most of the overhead from the stack tracer itself.
-	 */
-	stack_dump_trace[0] = ip;
-	max_stack_trace.nr_entries++;
+	/* Skip over the overhead of the stack tracer itself */
+	for (i = 0; i < max_stack_trace.nr_entries; i++) {
+		if (stack_dump_trace[i] == ip)
+			break;
+	}
 
 	/*
 	 * Now find where in the stack these are.
 	 */
-	i = 0;
+	x = 0;
 	start = stack;
 	top = (unsigned long *)
 		(((unsigned long)start & ~(THREAD_SIZE-1)) + THREAD_SIZE);
@@ -139,12 +127,15 @@ check_stack(unsigned long ip, unsigned long *stack)
 	while (i < max_stack_trace.nr_entries) {
 		int found = 0;
 
-		stack_dump_index[i] = this_size;
+		stack_dump_index[x] = this_size;
 		p = start;
 
 		for (; p < top && i < max_stack_trace.nr_entries; p++) {
+			if (stack_dump_trace[i] == ULONG_MAX)
+				break;
 			if (*p == stack_dump_trace[i]) {
-				this_size = stack_dump_index[i++] =
+				stack_dump_trace[x] = stack_dump_trace[i++];
+				this_size = stack_dump_index[x++] =
 					(top - p) * sizeof(unsigned long);
 				found = 1;
 				/* Start the search from here */
@@ -156,7 +147,7 @@ check_stack(unsigned long ip, unsigned long *stack)
 				 * out what that is, then figure it out
 				 * now.
 				 */
-				if (unlikely(!tracer_frame) && i == 1) {
+				if (unlikely(!tracer_frame)) {
 					tracer_frame = (p - stack) *
 						sizeof(unsigned long);
 					max_stack_size -= tracer_frame;
@@ -168,6 +159,10 @@ check_stack(unsigned long ip, unsigned long *stack)
 			i++;
 	}
 
+	max_stack_trace.nr_entries = x;
+	for (; x < i; x++)
+		stack_dump_trace[x] = ULONG_MAX;
+
 	if (task_stack_end_corrupted(current)) {
 		print_max_stack();
 		BUG();
@@ -192,23 +187,6 @@ stack_trace_call(unsigned long ip, unsigned long parent_ip,
 	if (per_cpu(trace_active, cpu)++ != 0)
 		goto out;
 
-	/*
-	 * When fentry is used, the traced function does not get
-	 * its stack frame set up, and we lose the parent.
-	 * The ip is pretty useless because the function tracer
-	 * was called before that function set up its stack frame.
-	 * In this case, we use the parent ip.
-	 *
-	 * By adding the return address of either the parent ip
-	 * or the current ip we can disregard most of the stack usage
-	 * caused by the stack tracer itself.
-	 *
-	 * The function tracer always reports the address of where the
-	 * mcount call was, but the stack will hold the return address.
-	 */
-	if (fentry)
-		ip = parent_ip;
-	else
 	ip += MCOUNT_INSN_SIZE;
 
 	check_stack(ip, &stack);
@@ -284,7 +262,7 @@ __next(struct seq_file *m, loff_t *pos)
 {
 	long n = *pos - 1;
 
-	if (n >= max_stack_trace.nr_entries || stack_dump_trace[n] == ULONG_MAX)
+	if (n > max_stack_trace.nr_entries || stack_dump_trace[n] == ULONG_MAX)
 		return NULL;
 
 	m->private = (void *)n;
@@ -354,7 +332,7 @@ static int t_show(struct seq_file *m, void *v)
 		seq_printf(m, "        Depth    Size   Location"
 			   "    (%d entries)\n"
 			   "        -----    ----   --------\n",
-			   max_stack_trace.nr_entries - 1);
+			   max_stack_trace.nr_entries);
 
 		if (!stack_tracer_enabled && !max_stack_size)
 			print_disabled(m);