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-rw-r--r--Documentation/kernel-parameters.txt6
-rw-r--r--Documentation/trace/events.txt3
-rw-r--r--Documentation/trace/ftrace.txt50
-rw-r--r--drivers/char/sysrq.c2
-rw-r--r--include/linux/ftrace.h49
-rw-r--r--include/linux/kernel.h11
-rw-r--r--include/linux/ring_buffer.h4
-rw-r--r--include/linux/tracepoint.h114
-rw-r--r--include/trace/define_trace.h5
-rw-r--r--include/trace/events/napi.h10
-rw-r--r--kernel/trace/ftrace.c30
-rw-r--r--kernel/trace/ring_buffer.c78
-rw-r--r--kernel/trace/ring_buffer_benchmark.c3
-rw-r--r--kernel/trace/trace.c99
-rw-r--r--kernel/trace/trace.h27
-rw-r--r--kernel/trace/trace_functions_graph.c164
-rw-r--r--kernel/trace/trace_irqsoff.c271
-rw-r--r--kernel/trace/trace_output.c2
-rw-r--r--kernel/trace/trace_selftest.c5
19 files changed, 723 insertions, 210 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 0c6c56076d1..567b7a8eb87 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -786,8 +786,12 @@ and is between 256 and 4096 characters. It is defined in the file
as early as possible in order to facilitate early
boot debugging.
- ftrace_dump_on_oops
+ ftrace_dump_on_oops[=orig_cpu]
[FTRACE] will dump the trace buffers on oops.
+ If no parameter is passed, ftrace will dump
+ buffers of all CPUs, but if you pass orig_cpu, it will
+ dump only the buffer of the CPU that triggered the
+ oops.
ftrace_filter=[function-list]
[FTRACE] Limit the functions traced by the function
diff --git a/Documentation/trace/events.txt b/Documentation/trace/events.txt
index 02ac6ed38b2..778ddf38b82 100644
--- a/Documentation/trace/events.txt
+++ b/Documentation/trace/events.txt
@@ -90,7 +90,8 @@ In order to facilitate early boot debugging, use boot option:
trace_event=[event-list]
-The format of this boot option is the same as described in section 2.1.
+event-list is a comma separated list of events. See section 2.1 for event
+format.
3. Defining an event-enabled tracepoint
=======================================
diff --git a/Documentation/trace/ftrace.txt b/Documentation/trace/ftrace.txt
index 03485bfbd79..557c1edecca 100644
--- a/Documentation/trace/ftrace.txt
+++ b/Documentation/trace/ftrace.txt
@@ -155,6 +155,9 @@ of ftrace. Here is a list of some of the key files:
to be traced. Echoing names of functions into this file
will limit the trace to only those functions.
+ This interface also allows for commands to be used. See the
+ "Filter commands" section for more details.
+
set_ftrace_notrace:
This has an effect opposite to that of
@@ -1337,12 +1340,14 @@ ftrace_dump_on_oops must be set. To set ftrace_dump_on_oops, one
can either use the sysctl function or set it via the proc system
interface.
- sysctl kernel.ftrace_dump_on_oops=1
+ sysctl kernel.ftrace_dump_on_oops=n
or
- echo 1 > /proc/sys/kernel/ftrace_dump_on_oops
+ echo n > /proc/sys/kernel/ftrace_dump_on_oops
+If n = 1, ftrace will dump buffers of all CPUs, if n = 2 ftrace will
+only dump the buffer of the CPU that triggered the oops.
Here's an example of such a dump after a null pointer
dereference in a kernel module:
@@ -1822,6 +1827,47 @@ this special filter via:
echo > set_graph_function
+Filter commands
+---------------
+
+A few commands are supported by the set_ftrace_filter interface.
+Trace commands have the following format:
+
+<function>:<command>:<parameter>
+
+The following commands are supported:
+
+- mod
+ This command enables function filtering per module. The
+ parameter defines the module. For example, if only the write*
+ functions in the ext3 module are desired, run:
+
+ echo 'write*:mod:ext3' > set_ftrace_filter
+
+ This command interacts with the filter in the same way as
+ filtering based on function names. Thus, adding more functions
+ in a different module is accomplished by appending (>>) to the
+ filter file. Remove specific module functions by prepending
+ '!':
+
+ echo '!writeback*:mod:ext3' >> set_ftrace_filter
+
+- traceon/traceoff
+ These commands turn tracing on and off when the specified
+ functions are hit. The parameter determines how many times the
+ tracing system is turned on and off. If unspecified, there is
+ no limit. For example, to disable tracing when a schedule bug
+ is hit the first 5 times, run:
+
+ echo '__schedule_bug:traceoff:5' > set_ftrace_filter
+
+ These commands are cumulative whether or not they are appended
+ to set_ftrace_filter. To remove a command, prepend it by '!'
+ and drop the parameter:
+
+ echo '!__schedule_bug:traceoff' > set_ftrace_filter
+
+
trace_pipe
----------
diff --git a/drivers/char/sysrq.c b/drivers/char/sysrq.c
index 59de2525d30..d4e8b213a46 100644
--- a/drivers/char/sysrq.c
+++ b/drivers/char/sysrq.c
@@ -289,7 +289,7 @@ static struct sysrq_key_op sysrq_showstate_blocked_op = {
static void sysrq_ftrace_dump(int key, struct tty_struct *tty)
{
- ftrace_dump();
+ ftrace_dump(DUMP_ALL);
}
static struct sysrq_key_op sysrq_ftrace_dump_op = {
.handler = sysrq_ftrace_dump,
diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index cc12b3c556b..41e46330d9b 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -82,9 +82,13 @@ void clear_ftrace_function(void);
extern void ftrace_stub(unsigned long a0, unsigned long a1);
#else /* !CONFIG_FUNCTION_TRACER */
-# define register_ftrace_function(ops) do { } while (0)
-# define unregister_ftrace_function(ops) do { } while (0)
-# define clear_ftrace_function(ops) do { } while (0)
+/*
+ * (un)register_ftrace_function must be a macro since the ops parameter
+ * must not be evaluated.
+ */
+#define register_ftrace_function(ops) ({ 0; })
+#define unregister_ftrace_function(ops) ({ 0; })
+static inline void clear_ftrace_function(void) { }
static inline void ftrace_kill(void) { }
static inline void ftrace_stop(void) { }
static inline void ftrace_start(void) { }
@@ -237,11 +241,13 @@ extern int skip_trace(unsigned long ip);
extern void ftrace_disable_daemon(void);
extern void ftrace_enable_daemon(void);
#else
-# define skip_trace(ip) ({ 0; })
-# define ftrace_force_update() ({ 0; })
-# define ftrace_set_filter(buf, len, reset) do { } while (0)
-# define ftrace_disable_daemon() do { } while (0)
-# define ftrace_enable_daemon() do { } while (0)
+static inline int skip_trace(unsigned long ip) { return 0; }
+static inline int ftrace_force_update(void) { return 0; }
+static inline void ftrace_set_filter(unsigned char *buf, int len, int reset)
+{
+}
+static inline void ftrace_disable_daemon(void) { }
+static inline void ftrace_enable_daemon(void) { }
static inline void ftrace_release_mod(struct module *mod) {}
static inline int register_ftrace_command(struct ftrace_func_command *cmd)
{
@@ -314,16 +320,16 @@ static inline void __ftrace_enabled_restore(int enabled)
extern void time_hardirqs_on(unsigned long a0, unsigned long a1);
extern void time_hardirqs_off(unsigned long a0, unsigned long a1);
#else
-# define time_hardirqs_on(a0, a1) do { } while (0)
-# define time_hardirqs_off(a0, a1) do { } while (0)
+ static inline void time_hardirqs_on(unsigned long a0, unsigned long a1) { }
+ static inline void time_hardirqs_off(unsigned long a0, unsigned long a1) { }
#endif
#ifdef CONFIG_PREEMPT_TRACER
extern void trace_preempt_on(unsigned long a0, unsigned long a1);
extern void trace_preempt_off(unsigned long a0, unsigned long a1);
#else
-# define trace_preempt_on(a0, a1) do { } while (0)
-# define trace_preempt_off(a0, a1) do { } while (0)
+ static inline void trace_preempt_on(unsigned long a0, unsigned long a1) { }
+ static inline void trace_preempt_off(unsigned long a0, unsigned long a1) { }
#endif
#ifdef CONFIG_FTRACE_MCOUNT_RECORD
@@ -352,6 +358,10 @@ struct ftrace_graph_ret {
int depth;
};
+/* Type of the callback handlers for tracing function graph*/
+typedef void (*trace_func_graph_ret_t)(struct ftrace_graph_ret *); /* return */
+typedef int (*trace_func_graph_ent_t)(struct ftrace_graph_ent *); /* entry */
+
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
/* for init task */
@@ -400,10 +410,6 @@ extern char __irqentry_text_end[];
#define FTRACE_RETFUNC_DEPTH 50
#define FTRACE_RETSTACK_ALLOC_SIZE 32
-/* Type of the callback handlers for tracing function graph*/
-typedef void (*trace_func_graph_ret_t)(struct ftrace_graph_ret *); /* return */
-typedef int (*trace_func_graph_ent_t)(struct ftrace_graph_ent *); /* entry */
-
extern int register_ftrace_graph(trace_func_graph_ret_t retfunc,
trace_func_graph_ent_t entryfunc);
@@ -441,6 +447,13 @@ static inline void unpause_graph_tracing(void)
static inline void ftrace_graph_init_task(struct task_struct *t) { }
static inline void ftrace_graph_exit_task(struct task_struct *t) { }
+static inline int register_ftrace_graph(trace_func_graph_ret_t retfunc,
+ trace_func_graph_ent_t entryfunc)
+{
+ return -1;
+}
+static inline void unregister_ftrace_graph(void) { }
+
static inline int task_curr_ret_stack(struct task_struct *tsk)
{
return -1;
@@ -492,7 +505,9 @@ static inline int test_tsk_trace_graph(struct task_struct *tsk)
return tsk->trace & TSK_TRACE_FL_GRAPH;
}
-extern int ftrace_dump_on_oops;
+enum ftrace_dump_mode;
+
+extern enum ftrace_dump_mode ftrace_dump_on_oops;
#ifdef CONFIG_PREEMPT
#define INIT_TRACE_RECURSION .trace_recursion = 0,
diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index 9365227dbaf..9fb1c129903 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -490,6 +490,13 @@ static inline void tracing_off(void) { }
static inline void tracing_off_permanent(void) { }
static inline int tracing_is_on(void) { return 0; }
#endif
+
+enum ftrace_dump_mode {
+ DUMP_NONE,
+ DUMP_ALL,
+ DUMP_ORIG,
+};
+
#ifdef CONFIG_TRACING
extern void tracing_start(void);
extern void tracing_stop(void);
@@ -571,7 +578,7 @@ __ftrace_vbprintk(unsigned long ip, const char *fmt, va_list ap);
extern int
__ftrace_vprintk(unsigned long ip, const char *fmt, va_list ap);
-extern void ftrace_dump(void);
+extern void ftrace_dump(enum ftrace_dump_mode oops_dump_mode);
#else
static inline void
ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3) { }
@@ -592,7 +599,7 @@ ftrace_vprintk(const char *fmt, va_list ap)
{
return 0;
}
-static inline void ftrace_dump(void) { }
+static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { }
#endif /* CONFIG_TRACING */
/*
diff --git a/include/linux/ring_buffer.h b/include/linux/ring_buffer.h
index c8297761e41..25b4f686d91 100644
--- a/include/linux/ring_buffer.h
+++ b/include/linux/ring_buffer.h
@@ -127,7 +127,9 @@ ring_buffer_consume(struct ring_buffer *buffer, int cpu, u64 *ts,
unsigned long *lost_events);
struct ring_buffer_iter *
-ring_buffer_read_start(struct ring_buffer *buffer, int cpu);
+ring_buffer_read_prepare(struct ring_buffer *buffer, int cpu);
+void ring_buffer_read_prepare_sync(void);
+void ring_buffer_read_start(struct ring_buffer_iter *iter);
void ring_buffer_read_finish(struct ring_buffer_iter *iter);
struct ring_buffer_event *
diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h
index 78b4bd3be49..1d85f9a6a19 100644
--- a/include/linux/tracepoint.h
+++ b/include/linux/tracepoint.h
@@ -33,6 +33,65 @@ struct tracepoint {
* Keep in sync with vmlinux.lds.h.
*/
+/*
+ * Connect a probe to a tracepoint.
+ * Internal API, should not be used directly.
+ */
+extern int tracepoint_probe_register(const char *name, void *probe);
+
+/*
+ * Disconnect a probe from a tracepoint.
+ * Internal API, should not be used directly.
+ */
+extern int tracepoint_probe_unregister(const char *name, void *probe);
+
+extern int tracepoint_probe_register_noupdate(const char *name, void *probe);
+extern int tracepoint_probe_unregister_noupdate(const char *name, void *probe);
+extern void tracepoint_probe_update_all(void);
+
+struct tracepoint_iter {
+ struct module *module;
+ struct tracepoint *tracepoint;
+};
+
+extern void tracepoint_iter_start(struct tracepoint_iter *iter);
+extern void tracepoint_iter_next(struct tracepoint_iter *iter);
+extern void tracepoint_iter_stop(struct tracepoint_iter *iter);
+extern void tracepoint_iter_reset(struct tracepoint_iter *iter);
+extern int tracepoint_get_iter_range(struct tracepoint **tracepoint,
+ struct tracepoint *begin, struct tracepoint *end);
+
+/*
+ * tracepoint_synchronize_unregister must be called between the last tracepoint
+ * probe unregistration and the end of module exit to make sure there is no
+ * caller executing a probe when it is freed.
+ */
+static inline void tracepoint_synchronize_unregister(void)
+{
+ synchronize_sched();
+}
+
+#define PARAMS(args...) args
+
+#ifdef CONFIG_TRACEPOINTS
+extern void tracepoint_update_probe_range(struct tracepoint *begin,
+ struct tracepoint *end);
+#else
+static inline void tracepoint_update_probe_range(struct tracepoint *begin,
+ struct tracepoint *end)
+{ }
+#endif /* CONFIG_TRACEPOINTS */
+
+#endif /* _LINUX_TRACEPOINT_H */
+
+/*
+ * Note: we keep the TRACE_EVENT and DECLARE_TRACE outside the include
+ * file ifdef protection.
+ * This is due to the way trace events work. If a file includes two
+ * trace event headers under one "CREATE_TRACE_POINTS" the first include
+ * will override the TRACE_EVENT and break the second include.
+ */
+
#ifndef DECLARE_TRACE
#define TP_PROTO(args...) args
@@ -96,9 +155,6 @@ struct tracepoint {
#define EXPORT_TRACEPOINT_SYMBOL(name) \
EXPORT_SYMBOL(__tracepoint_##name)
-extern void tracepoint_update_probe_range(struct tracepoint *begin,
- struct tracepoint *end);
-
#else /* !CONFIG_TRACEPOINTS */
#define DECLARE_TRACE(name, proto, args) \
static inline void _do_trace_##name(struct tracepoint *tp, proto) \
@@ -119,61 +175,9 @@ extern void tracepoint_update_probe_range(struct tracepoint *begin,
#define EXPORT_TRACEPOINT_SYMBOL_GPL(name)
#define EXPORT_TRACEPOINT_SYMBOL(name)
-static inline void tracepoint_update_probe_range(struct tracepoint *begin,
- struct tracepoint *end)
-{ }
#endif /* CONFIG_TRACEPOINTS */
#endif /* DECLARE_TRACE */
-/*
- * Connect a probe to a tracepoint.
- * Internal API, should not be used directly.
- */
-extern int tracepoint_probe_register(const char *name, void *probe);
-
-/*
- * Disconnect a probe from a tracepoint.
- * Internal API, should not be used directly.
- */
-extern int tracepoint_probe_unregister(const char *name, void *probe);
-
-extern int tracepoint_probe_register_noupdate(const char *name, void *probe);
-extern int tracepoint_probe_unregister_noupdate(const char *name, void *probe);
-extern void tracepoint_probe_update_all(void);
-
-struct tracepoint_iter {
- struct module *module;
- struct tracepoint *tracepoint;
-};
-
-extern void tracepoint_iter_start(struct tracepoint_iter *iter);
-extern void tracepoint_iter_next(struct tracepoint_iter *iter);
-extern void tracepoint_iter_stop(struct tracepoint_iter *iter);
-extern void tracepoint_iter_reset(struct tracepoint_iter *iter);
-extern int tracepoint_get_iter_range(struct tracepoint **tracepoint,
- struct tracepoint *begin, struct tracepoint *end);
-
-/*
- * tracepoint_synchronize_unregister must be called between the last tracepoint
- * probe unregistration and the end of module exit to make sure there is no
- * caller executing a probe when it is freed.
- */
-static inline void tracepoint_synchronize_unregister(void)
-{
- synchronize_sched();
-}
-
-#define PARAMS(args...) args
-
-#endif /* _LINUX_TRACEPOINT_H */
-
-/*
- * Note: we keep the TRACE_EVENT outside the include file ifdef protection.
- * This is due to the way trace events work. If a file includes two
- * trace event headers under one "CREATE_TRACE_POINTS" the first include
- * will override the TRACE_EVENT and break the second include.
- */
-
#ifndef TRACE_EVENT
/*
* For use with the TRACE_EVENT macro:
diff --git a/include/trace/define_trace.h b/include/trace/define_trace.h
index 5acfb1eb4df..1dfab540151 100644
--- a/include/trace/define_trace.h
+++ b/include/trace/define_trace.h
@@ -65,6 +65,10 @@
#include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
+/* Make all open coded DECLARE_TRACE nops */
+#undef DECLARE_TRACE
+#define DECLARE_TRACE(name, proto, args)
+
#ifdef CONFIG_EVENT_TRACING
#include <trace/ftrace.h>
#endif
@@ -75,6 +79,7 @@
#undef DEFINE_EVENT
#undef DEFINE_EVENT_PRINT
#undef TRACE_HEADER_MULTI_READ
+#undef DECLARE_TRACE
/* Only undef what we defined in this file */
#ifdef UNDEF_TRACE_INCLUDE_FILE
diff --git a/include/trace/events/napi.h b/include/trace/events/napi.h
index a8989c4547e..188deca2f3c 100644
--- a/include/trace/events/napi.h
+++ b/include/trace/events/napi.h
@@ -1,4 +1,7 @@
-#ifndef _TRACE_NAPI_H_
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM napi
+
+#if !defined(_TRACE_NAPI_H) || defined(TRACE_HEADER_MULTI_READ)
#define _TRACE_NAPI_H_
#include <linux/netdevice.h>
@@ -8,4 +11,7 @@ DECLARE_TRACE(napi_poll,
TP_PROTO(struct napi_struct *napi),
TP_ARGS(napi));
-#endif
+#endif /* _TRACE_NAPI_H_ */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index aa3a92b511e..32837e19e3b 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -264,6 +264,7 @@ struct ftrace_profile {
unsigned long counter;
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
unsigned long long time;
+ unsigned long long time_squared;
#endif
};
@@ -366,9 +367,9 @@ static int function_stat_headers(struct seq_file *m)
{
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
seq_printf(m, " Function "
- "Hit Time Avg\n"
+ "Hit Time Avg s^2\n"
" -------- "
- "--- ---- ---\n");
+ "--- ---- --- ---\n");
#else
seq_printf(m, " Function Hit\n"
" -------- ---\n");
@@ -384,6 +385,7 @@ static int function_stat_show(struct seq_file *m, void *v)
static DEFINE_MUTEX(mutex);
static struct trace_seq s;
unsigned long long avg;
+ unsigned long long stddev;
#endif
kallsyms_lookup(rec->ip, NULL, NULL, NULL, str);
@@ -394,11 +396,25 @@ static int function_stat_show(struct seq_file *m, void *v)
avg = rec->time;
do_div(avg, rec->counter);
+ /* Sample standard deviation (s^2) */
+ if (rec->counter <= 1)
+ stddev = 0;
+ else {
+ stddev = rec->time_squared - rec->counter * avg * avg;
+ /*
+ * Divide only 1000 for ns^2 -> us^2 conversion.
+ * trace_print_graph_duration will divide 1000 again.
+ */
+ do_div(stddev, (rec->counter - 1) * 1000);
+ }
+
mutex_lock(&mutex);
trace_seq_init(&s);
trace_print_graph_duration(rec->time, &s);
trace_seq_puts(&s, " ");
trace_print_graph_duration(avg, &s);
+ trace_seq_puts(&s, " ");
+ trace_print_graph_duration(stddev, &s);
trace_print_seq(m, &s);
mutex_unlock(&mutex);
#endif
@@ -650,6 +666,10 @@ static void profile_graph_return(struct ftrace_graph_ret *trace)
if (!stat->hash || !ftrace_profile_enabled)
goto out;
+ /* If the calltime was zero'd ignore it */
+ if (!trace->calltime)
+ goto out;
+
calltime = trace->rettime - trace->calltime;
if (!(trace_flags & TRACE_ITER_GRAPH_TIME)) {
@@ -668,8 +688,10 @@ static void profile_graph_return(struct ftrace_graph_ret *trace)
}
rec = ftrace_find_profiled_func(stat, trace->func);
- if (rec)
+ if (rec) {
rec->time += calltime;
+ rec->time_squared += calltime * calltime;
+ }
out:
local_irq_restore(flags);
@@ -3338,11 +3360,11 @@ void unregister_ftrace_graph(void)
goto out;
ftrace_graph_active--;
- unregister_trace_sched_switch(ftrace_graph_probe_sched_switch);
ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub;
ftrace_graph_entry = ftrace_graph_entry_stub;
ftrace_shutdown(FTRACE_STOP_FUNC_RET);
unregister_pm_notifier(&ftrace_suspend_notifier);
+ unregister_trace_sched_switch(ftrace_graph_probe_sched_switch);
out:
mutex_unlock(&ftrace_lock);
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 5885cdfc41f..7f6059c5aa9 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -2000,17 +2000,13 @@ rb_add_time_stamp(struct ring_buffer_per_cpu *cpu_buffer,
u64 *ts, u64 *delta)
{
struct ring_buffer_event *event;
- static int once;
int ret;
- if (unlikely(*delta > (1ULL << 59) && !once++)) {
- printk(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);
- WARN_ON(1);
- }
+ 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
@@ -3332,23 +3328,30 @@ ring_buffer_consume(struct ring_buffer *buffer, int cpu, u64 *ts,
EXPORT_SYMBOL_GPL(ring_buffer_consume);
/**
- * ring_buffer_read_start - start a non consuming read of the buffer
+ * ring_buffer_read_prepare - Prepare for a non consuming read of the buffer
* @buffer: The ring buffer to read from
* @cpu: The cpu buffer to iterate over
*
- * This starts up an iteration through the buffer. It also disables
- * the recording to the buffer until the reading is finished.
- * This prevents the reading from being corrupted. This is not
- * a consuming read, so a producer is not expected.
+ * This performs the initial preparations necessary to iterate
+ * through the buffer. Memory is allocated, buffer recording
+ * is disabled, and the iterator pointer is returned to the caller.
*
- * Must be paired with ring_buffer_finish.
+ * Disabling buffer recordng prevents the reading from being
+ * corrupted. This is not a consuming read, so a producer is not
+ * expected.
+ *
+ * After a sequence of ring_buffer_read_prepare calls, the user is
+ * expected to make at least one call to ring_buffer_prepare_sync.
+ * Afterwards, ring_buffer_read_start is invoked to get things going
+ * for real.
+ *
+ * This overall must be paired with ring_buffer_finish.
*/
struct ring_buffer_iter *
-ring_buffer_read_start(struct ring_buffer *buffer, int cpu)
+ring_buffer_read_prepare(struct ring_buffer *buffer, int cpu)
{
struct ring_buffer_per_cpu *cpu_buffer;
struct ring_buffer_iter *iter;
- unsigned long flags;
if (!cpumask_test_cpu(cpu, buffer->cpumask))
return NULL;
@@ -3362,15 +3365,52 @@ ring_buffer_read_start(struct ring_buffer *buffer, int cpu)
iter->cpu_buffer = cpu_buffer;
atomic_inc(&cpu_buffer->record_disabled);
+
+ return iter;
+}
+EXPORT_SYMBOL_GPL(ring_buffer_read_prepare);
+
+/**
+ * ring_buffer_read_prepare_sync - Synchronize a set of prepare calls
+ *
+ * All previously invoked ring_buffer_read_prepare calls to prepare
+ * iterators will be synchronized. Afterwards, read_buffer_read_start
+ * calls on those iterators are allowed.
+ */
+void
+ring_buffer_read_prepare_sync(void)
+{
synchronize_sched();
+}
+EXPORT_SYMBOL_GPL(ring_buffer_read_prepare_sync);
+
+/**
+ * ring_buffer_read_start - start a non consuming read of the buffer
+ * @iter: The iterator returned by ring_buffer_read_prepare
+ *
+ * This finalizes the startup of an iteration through the buffer.
+ * The iterator comes from a call to ring_buffer_read_prepare and
+ * an intervening ring_buffer_read_prepare_sync must have been
+ * performed.
+ *
+ * Must be paired with ring_buffer_finish.
+ */
+void
+ring_buffer_read_start(struct ring_buffer_iter *iter)
+{
+ struct ring_buffer_per_cpu *cpu_buffer;
+ unsigned long flags;
+
+ if (!iter)
+ return;
+
+ cpu_buffer = iter->cpu_buffer;
spin_lock_irqsave(&cpu_buffer->reader_lock, flags);
arch_spin_lock(&cpu_buffer->lock);
rb_iter_reset(iter);
arch_spin_unlock(&cpu_buffer->lock);
spin_unlock_irqrestore(&cpu_buffer->reader_lock, flags);
-
- return iter;
}
EXPORT_SYMBOL_GPL(ring_buffer_read_start);
diff --git a/kernel/trace/ring_buffer_benchmark.c b/kernel/trace/ring_buffer_benchmark.c
index dc56556b55a..302f8a61463 100644
--- a/kernel/trace/ring_buffer_benchmark.c
+++ b/kernel/trace/ring_buffer_benchmark.c
@@ -113,7 +113,8 @@ static enum event_status read_page(int cpu)
ret = ring_buffer_read_page(buffer, &bpage, PAGE_SIZE, cpu, 1);
if (ret >= 0) {
rpage = bpage;
- commit = local_read(&rpage->commit);
+ /* The commit may have missed event flags set, clear them */
+ commit = local_read(&rpage->commit) & 0xfffff;
for (i = 0; i < commit && !kill_test; i += inc) {
if (i >= (PAGE_SIZE - offsetof(struct rb_page, data))) {
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 60f3b628973..756d7283318 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -117,9 +117,12 @@ static cpumask_var_t __read_mostly tracing_buffer_mask;
*
* It is default off, but you can enable it with either specifying
* "ftrace_dump_on_oops" in the kernel command line, or setting
- * /proc/sys/kernel/ftrace_dump_on_oops to true.
+ * /proc/sys/kernel/ftrace_dump_on_oops
+ * Set 1 if you want to dump buffers of all CPUs
+ * Set 2 if you want to dump the buffer of the CPU that triggered oops
*/
-int ftrace_dump_on_oops;
+
+enum ftrace_dump_mode ftrace_dump_on_oops;
static int tracing_set_tracer(const char *buf);
@@ -139,8 +142,17 @@ __setup("ftrace=", set_cmdline_ftrace);
static int __init set_ftrace_dump_on_oops(char *str)
{
- ftrace_dump_on_oops = 1;
- return 1;
+ if (*str++ != '=' || !*str) {
+ ftrace_dump_on_oops = DUMP_ALL;
+ return 1;
+ }
+
+ if (!strcmp("orig_cpu", str)) {
+ ftrace_dump_on_oops = DUMP_ORIG;
+ return 1;
+ }
+
+ return 0;
}
__setup("ftrace_dump_on_oops", set_ftrace_dump_on_oops);
@@ -1571,7 +1583,7 @@ __find_next_entry(struct trace_iterator *iter, int *ent_cpu,
{
struct ring_buffer *buffer = iter->tr->buffer;
struct trace_entry *ent, *next = NULL;
- unsigned long lost_events, next_lost = 0;
+ unsigned long lost_events = 0, next_lost = 0;
int cpu_file = iter->cpu_file;
u64 next_ts = 0, ts;
int next_cpu = -1;
@@ -1796,7 +1808,7 @@ static void print_func_help_header(struct seq_file *m)
}
-static void
+void
print_trace_header(struct seq_file *m, struct trace_iterator *iter)
{
unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK);
@@ -2005,7 +2017,7 @@ static enum print_line_t print_bin_fmt(struct trace_iterator *iter)
return event ? event->binary(iter, 0) : TRACE_TYPE_HANDLED;
}
-static int trace_empty(struct trace_iterator *iter)
+int trace_empty(struct trace_iterator *iter)
{
int cpu;
@@ -2072,6 +2084,23 @@ static enum print_line_t print_trace_line(struct trace_iterator *iter)
return print_trace_fmt(iter);
}
+void trace_default_header(struct seq_file *m)
+{
+ struct trace_iterator *iter = m->private;
+
+ if (iter->iter_flags & TRACE_FILE_LAT_FMT) {
+ /* print nothing if the buffers are empty */
+ if (trace_empty(iter))
+ return;
+ print_trace_header(m, iter);
+ if (!(trace_flags & TRACE_ITER_VERBOSE))
+ print_lat_help_header(m);
+ } else {
+ if (!(trace_flags & TRACE_ITER_VERBOSE))
+ print_func_help_header(m);
+ }
+}
+
static int s_show(struct seq_file *m, void *v)
{
struct trace_iterator *iter = v;
@@ -2084,17 +2113,9 @@ static int s_show(struct seq_file *m, void *v)
}
if (iter->trace && iter->trace->print_header)
iter->trace->print_header(m);
- else if (iter->iter_flags & TRACE_FILE_LAT_FMT) {
- /* print nothing if the buffers are empty */
- if (trace_empty(iter))
- return 0;
- print_trace_header(m, iter);
- if (!(trace_flags & TRACE_ITER_VERBOSE))
- print_lat_help_header(m);
- } else {
- if (!(trace_flags & TRACE_ITER_VERBOSE))
- print_func_help_header(m);
- }
+ else
+ trace_default_header(m);
+
} else if (iter->leftover) {
/*
* If we filled the seq_file buffer earlier, we
@@ -2180,15 +2201,20 @@ __tracing_open(struct inode *inode, struct file *file)
if (iter->cpu_file == TRACE_PIPE_ALL_CPU) {
for_each_tracing_cpu(cpu) {
-
iter->buffer_iter[cpu] =
- ring_buffer_read_start(iter->tr->buffer, cpu);
+ ring_buffer_read_prepare(iter->tr->buffer, cpu);
+ }
+ ring_buffer_read_prepare_sync();
+ for_each_tracing_cpu(cpu) {
+ ring_buffer_read_start(iter->buffer_iter[cpu]);
tracing_iter_reset(iter, cpu);
}
} else {
cpu = iter->cpu_file;
iter->buffer_iter[cpu] =
- ring_buffer_read_start(iter->tr->buffer, cpu);
+ ring_buffer_read_prepare(iter->tr->buffer, cpu);
+ ring_buffer_read_prepare_sync();
+ ring_buffer_read_start(iter->buffer_iter[cpu]);
tracing_iter_reset(iter, cpu);
}
@@ -4338,7 +4364,7 @@ static int trace_panic_handler(struct notifier_block *this,
unsigned long event, void *unused)
{
if (ftrace_dump_on_oops)
- ftrace_dump();
+ ftrace_dump(ftrace_dump_on_oops);
return NOTIFY_OK;
}
@@ -4355,7 +4381,7 @@ static int trace_die_handler(struct notifier_block *self,
switch (val) {
case DIE_OOPS:
if (ftrace_dump_on_oops)
- ftrace_dump();
+ ftrace_dump(ftrace_dump_on_oops);
break;
default:
break;
@@ -4396,7 +4422,8 @@ trace_printk_seq(struct trace_seq *s)
trace_seq_init(s);
}
-static void __ftrace_dump(bool disable_tracing)
+static void
+__ftrace_dump(bool disable_tracing, enum ftrace_dump_mode oops_dump_mode)
{
static arch_spinlock_t ftrace_dump_lock =
(arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED;
@@ -4429,12 +4456,25 @@ static void __ftrace_dump(bool disable_tracing)
/* don't look at user memory in panic mode */
trace_flags &= ~TRACE_ITER_SYM_USEROBJ;
- printk(KERN_TRACE "Dumping ftrace buffer:\n");
-
/* Simulate the iterator */
iter.tr = &global_trace;
iter.trace = current_trace;
- iter.cpu_file = TRACE_PIPE_ALL_CPU;
+
+ switch (oops_dump_mode) {
+ case DUMP_ALL:
+ iter.cpu_file = TRACE_PIPE_ALL_CPU;
+ break;
+ case DUMP_ORIG:
+ iter.cpu_file = raw_smp_processor_id();
+ break;
+ case DUMP_NONE:
+ goto out_enable;
+ default:
+ printk(KERN_TRACE "Bad dumping mode, switching to all CPUs dump\n");
+ iter.cpu_file = TRACE_PIPE_ALL_CPU;
+ }
+
+ printk(KERN_TRACE "Dumping ftrace buffer:\n");
/*
* We need to stop all tracing on all CPUS to read the
@@ -4473,6 +4513,7 @@ static void __ftrace_dump(bool disable_tracing)
else
printk(KERN_TRACE "---------------------------------\n");
+ out_enable:
/* Re-enable tracing if requested */
if (!disable_tracing) {
trace_flags |= old_userobj;
@@ -4489,9 +4530,9 @@ static void __ftrace_dump(bool disable_tracing)
}
/* By default: disable tracing after the dump */
-void ftrace_dump(void)
+void ftrace_dump(enum ftrace_dump_mode oops_dump_mode)
{
- __ftrace_dump(true);
+ __ftrace_dump(true, oops_dump_mode);
}
__init static int tracer_alloc_buffers(void)
diff --git a/kernel/trace/trace.h b/ker