* [RFC v2 0/4] tracing: Add support to record and display tgid of tasks
@ 2017-06-04 4:03 Joel Fernandes
2017-06-04 4:03 ` [RFC v2 1/4] tracing: Remove unused declaration of trace_stop_cmdline_recording Joel Fernandes
` (3 more replies)
0 siblings, 4 replies; 6+ messages in thread
From: Joel Fernandes @ 2017-06-04 4:03 UTC (permalink / raw)
To: linux-kernel; +Cc: Joel Fernandes, Steven Rostedt, Ingo Molnar, kernel-team
Hi Steven, Ingo,
Here is a rework of the last RFC [1] I posted. Its a a complete rewrite from
scratch to be more upstream friendly.
Android systrace viewer heavily depends on the tgid to group tasks. tgid is
also useful for analyzing traces and generating stats for groups of tasks.
Basically in this approach I try to make sure there is no overhead in terms of
runtime or space usage for existing users who don't need tgid. Only if the
trace option is enabled will the tgid table which does the mapping be allocated
and used.
I tested these and they are showing good results so far, looking forward to
getting your feedback and thoughts on them. Thank you.
[1] https://patchwork.kernel.org/patch/9728283/
Joel Fernandes (4):
tracing: Remove unused declaration of trace_stop_cmdline_recording
tracing: Add support for recording tgid of tasks
tracing: Add support for display of tgid in trace output
tracing/ftrace: Add support to record and display tgid
include/linux/trace_events.h | 10 ++-
kernel/trace/blktrace.c | 2 +-
kernel/trace/trace.c | 141 +++++++++++++++++++++++++++--------
kernel/trace/trace.h | 9 ++-
kernel/trace/trace_events.c | 84 ++++++++++++++++++---
kernel/trace/trace_functions.c | 24 +++++-
kernel/trace/trace_functions_graph.c | 4 +-
kernel/trace/trace_output.c | 9 +++
kernel/trace/trace_sched_switch.c | 67 ++++++++++++-----
kernel/trace/trace_selftest.c | 2 +-
10 files changed, 283 insertions(+), 69 deletions(-)
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: kernel-team@android.com
Signed-off-by: Joel Fernandes <joelaf@google.com>
--
2.13.0.506.g27d5fe0cd-goog
^ permalink raw reply [flat|nested] 6+ messages in thread
* [RFC v2 1/4] tracing: Remove unused declaration of trace_stop_cmdline_recording
2017-06-04 4:03 [RFC v2 0/4] tracing: Add support to record and display tgid of tasks Joel Fernandes
@ 2017-06-04 4:03 ` Joel Fernandes
2017-06-04 4:03 ` [RFC v2 2/4] tracing: Add support for recording tgid of tasks Joel Fernandes
` (2 subsequent siblings)
3 siblings, 0 replies; 6+ messages in thread
From: Joel Fernandes @ 2017-06-04 4:03 UTC (permalink / raw)
To: linux-kernel; +Cc: Joel Fernandes, kernel-team, Steven Rostedt, Ingo Molnar
trace_stop_cmdline_recording declaration isn't in use, remove it.
Cc: kernel-team@android.com
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Joel Fernandes <joelaf@google.com>
---
kernel/trace/trace.c | 2 --
1 file changed, 2 deletions(-)
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 1122f151466f..63deff9cdf2c 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -1910,8 +1910,6 @@ static void tracing_stop_tr(struct trace_array *tr)
raw_spin_unlock_irqrestore(&tr->start_lock, flags);
}
-void trace_stop_cmdline_recording(void);
-
static int trace_save_cmdline(struct task_struct *tsk)
{
unsigned pid, idx;
--
2.13.0.506.g27d5fe0cd-goog
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [RFC v2 2/4] tracing: Add support for recording tgid of tasks
2017-06-04 4:03 [RFC v2 0/4] tracing: Add support to record and display tgid of tasks Joel Fernandes
2017-06-04 4:03 ` [RFC v2 1/4] tracing: Remove unused declaration of trace_stop_cmdline_recording Joel Fernandes
@ 2017-06-04 4:03 ` Joel Fernandes
2017-06-04 5:44 ` Joel Fernandes
2017-06-04 4:03 ` [RFC v2 3/4] tracing: Add support for display of tgid in trace output Joel Fernandes
2017-06-04 4:03 ` [RFC v2 4/4] tracing/ftrace: Add support to record and display tgid Joel Fernandes
3 siblings, 1 reply; 6+ messages in thread
From: Joel Fernandes @ 2017-06-04 4:03 UTC (permalink / raw)
To: linux-kernel
Cc: Joel Fernandes, kernel-team, Steven Rostedt, Ingo Molnar,
Jens Axboe, open list:BLOCK LAYER
Inorder to support recording of tgid, the following changes are made:
- Introduce a new API for optionally recording the tgid along with the task's
comm which replaces the existing '*cmdline*' APIs.
- reuse the existing sched_switch and sched_wakeup probes
- replace all uses of the old API
- add a new option 'record-tgid' to enable recording of tgid
This will have no memory or runtime overhead if record-tgid option isn't enabled.
Cc: kernel-team@android.com
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Joel Fernandes <joelaf@google.com>
---
include/linux/trace_events.h | 10 ++++-
kernel/trace/blktrace.c | 2 +-
kernel/trace/trace.c | 79 ++++++++++++++++++++++++++++------
kernel/trace/trace.h | 9 +++-
kernel/trace/trace_events.c | 83 ++++++++++++++++++++++++++++++------
kernel/trace/trace_functions.c | 5 ++-
kernel/trace/trace_functions_graph.c | 4 +-
kernel/trace/trace_sched_switch.c | 67 +++++++++++++++++++++--------
kernel/trace/trace_selftest.c | 2 +-
9 files changed, 208 insertions(+), 53 deletions(-)
diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h
index a556805eff8a..bc54f1469971 100644
--- a/include/linux/trace_events.h
+++ b/include/linux/trace_events.h
@@ -151,7 +151,11 @@ trace_event_buffer_lock_reserve(struct ring_buffer **current_buffer,
int type, unsigned long len,
unsigned long flags, int pc);
-void tracing_record_cmdline(struct task_struct *tsk);
+void tracing_record_taskinfo(struct task_struct **tasks, int len, bool cmd,
+ bool tgid);
+
+void tracing_record_taskinfo_single(struct task_struct *task, bool cmd,
+ bool tgid);
int trace_output_call(struct trace_iterator *iter, char *name, char *fmt, ...);
@@ -290,6 +294,7 @@ struct trace_subsystem_dir;
enum {
EVENT_FILE_FL_ENABLED_BIT,
EVENT_FILE_FL_RECORDED_CMD_BIT,
+ EVENT_FILE_FL_RECORDED_TGID_BIT,
EVENT_FILE_FL_FILTERED_BIT,
EVENT_FILE_FL_NO_SET_FILTER_BIT,
EVENT_FILE_FL_SOFT_MODE_BIT,
@@ -315,6 +320,7 @@ enum {
enum {
EVENT_FILE_FL_ENABLED = (1 << EVENT_FILE_FL_ENABLED_BIT),
EVENT_FILE_FL_RECORDED_CMD = (1 << EVENT_FILE_FL_RECORDED_CMD_BIT),
+ EVENT_FILE_FL_RECORDED_TGID = (1 << EVENT_FILE_FL_RECORDED_TGID_BIT),
EVENT_FILE_FL_FILTERED = (1 << EVENT_FILE_FL_FILTERED_BIT),
EVENT_FILE_FL_NO_SET_FILTER = (1 << EVENT_FILE_FL_NO_SET_FILTER_BIT),
EVENT_FILE_FL_SOFT_MODE = (1 << EVENT_FILE_FL_SOFT_MODE_BIT),
@@ -463,7 +469,7 @@ int trace_set_clr_event(const char *system, const char *event, int set);
#define event_trace_printk(ip, fmt, args...) \
do { \
__trace_printk_check_format(fmt, ##args); \
- tracing_record_cmdline(current); \
+ tracing_record_taskinfo_single(current, true, false); \
if (__builtin_constant_p(fmt)) { \
static const char *trace_printk_fmt \
__attribute__((section("__trace_printk_fmt"))) = \
diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index 193c5f5e3f79..d7394cdf899e 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -236,7 +236,7 @@ static void __blk_add_trace(struct blk_trace *bt, sector_t sector, int bytes,
cpu = raw_smp_processor_id();
if (blk_tracer) {
- tracing_record_cmdline(current);
+ tracing_record_taskinfo_single(current, true, false);
buffer = blk_tr->trace_buffer.buffer;
pc = preempt_count();
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 63deff9cdf2c..7be21ae4f0a8 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -87,7 +87,7 @@ dummy_set_flag(struct trace_array *tr, u32 old_flags, u32 bit, int set)
* tracing is active, only save the comm when a trace event
* occurred.
*/
-static DEFINE_PER_CPU(bool, trace_cmdline_save);
+static DEFINE_PER_CPU(bool, trace_taskinfo_save);
/*
* Kill all tracing for good (never come back).
@@ -790,7 +790,7 @@ EXPORT_SYMBOL_GPL(tracing_on);
static __always_inline void
__buffer_unlock_commit(struct ring_buffer *buffer, struct ring_buffer_event *event)
{
- __this_cpu_write(trace_cmdline_save, true);
+ __this_cpu_write(trace_taskinfo_save, true);
/* If this is the temp buffer, we need to commit fully */
if (this_cpu_read(trace_buffered_event) == event) {
@@ -1709,6 +1709,15 @@ void tracing_reset_all_online_cpus(void)
}
}
+static unsigned int *tgid_map;
+
+void tracing_alloc_tgid_map(void)
+{
+ tgid_map = kzalloc((PID_MAX_DEFAULT + 1) * sizeof(*tgid_map),
+ GFP_KERNEL);
+ WARN_ONCE(!tgid_map, "Allocation of tgid_map failed\n");
+}
+
#define SAVED_CMDLINES_DEFAULT 128
#define NO_CMDLINE_MAP UINT_MAX
static arch_spinlock_t trace_cmdline_lock = __ARCH_SPIN_LOCK_UNLOCKED;
@@ -1722,7 +1731,7 @@ struct saved_cmdlines_buffer {
static struct saved_cmdlines_buffer *savedcmd;
/* temporary disable recording */
-static atomic_t trace_record_cmdline_disabled __read_mostly;
+static atomic_t trace_record_taskinfo_disabled __read_mostly;
static inline char *get_saved_cmdlines(int idx)
{
@@ -1990,16 +1999,55 @@ void trace_find_cmdline(int pid, char comm[])
preempt_enable();
}
-void tracing_record_cmdline(struct task_struct *tsk)
+unsigned int trace_find_tgid(unsigned int pid)
+{
+ if (!tgid_map || !pid || unlikely(pid > PID_MAX_DEFAULT))
+ return 0;
+
+ return tgid_map[pid];
+}
+
+static int trace_save_tgid(struct task_struct *tsk)
+{
+ if (!tgid_map || !tsk->pid || unlikely(tsk->pid > PID_MAX_DEFAULT))
+ return 0;
+
+ tgid_map[tsk->pid] = tsk->tgid;
+ return 1;
+}
+
+void tracing_record_taskinfo(struct task_struct **tasks, int len,
+ bool cmdline, bool tgid)
{
- if (atomic_read(&trace_record_cmdline_disabled) || !tracing_is_on())
+ int i;
+
+ if (unlikely(!cmdline && !tgid))
return;
- if (!__this_cpu_read(trace_cmdline_save))
+ if (atomic_read(&trace_record_taskinfo_disabled) || !tracing_is_on())
return;
- if (trace_save_cmdline(tsk))
- __this_cpu_write(trace_cmdline_save, false);
+ if (!__this_cpu_read(trace_taskinfo_save))
+ return;
+
+ for (i = 0; i < len; i++) {
+ if (cmdline && !trace_save_cmdline(tasks[i]))
+ break;
+ if (tgid && !trace_save_tgid(tasks[i]))
+ break;
+ }
+
+ if (i == len)
+ __this_cpu_write(trace_taskinfo_save, false);
+}
+
+void tracing_record_taskinfo_single(struct task_struct *task,
+ bool cmd, bool tgid)
+{
+ struct task_struct *tasks[1];
+
+ tasks[0] = task;
+ return tracing_record_taskinfo(tasks, 1, cmd, tgid);
}
/*
@@ -2761,7 +2809,7 @@ void trace_printk_init_buffers(void)
* allocated here, then this was called by module code.
*/
if (global_trace.trace_buffer.buffer)
- tracing_start_cmdline_record();
+ tracing_start_taskinfo_record(true, false);
}
void trace_printk_start_comm(void)
@@ -2769,7 +2817,7 @@ void trace_printk_start_comm(void)
/* Start tracing comms if trace printk is set */
if (!buffers_allocated)
return;
- tracing_start_cmdline_record();
+ tracing_start_taskinfo_record(true, false);
}
static void trace_printk_start_stop_comm(int enabled)
@@ -2778,9 +2826,9 @@ static void trace_printk_start_stop_comm(int enabled)
return;
if (enabled)
- tracing_start_cmdline_record();
+ tracing_start_taskinfo_record(true, false);
else
- tracing_stop_cmdline_record();
+ tracing_stop_taskinfo_record(true, false);
}
/**
@@ -3144,7 +3192,7 @@ static void *s_start(struct seq_file *m, loff_t *pos)
#endif
if (!iter->snapshot)
- atomic_inc(&trace_record_cmdline_disabled);
+ atomic_inc(&trace_record_taskinfo_disabled);
if (*pos != iter->pos) {
iter->ent = NULL;
@@ -3189,7 +3237,7 @@ static void s_stop(struct seq_file *m, void *p)
#endif
if (!iter->snapshot)
- atomic_dec(&trace_record_cmdline_disabled);
+ atomic_dec(&trace_record_taskinfo_disabled);
trace_access_unlock(iter->cpu_file);
trace_event_read_unlock();
@@ -4236,6 +4284,9 @@ int set_tracer_flag(struct trace_array *tr, unsigned int mask, int enabled)
if (mask == TRACE_ITER_RECORD_CMD)
trace_event_enable_cmd_record(enabled);
+ if (mask == TRACE_ITER_RECORD_TGID)
+ trace_event_enable_tgid_record(enabled);
+
if (mask == TRACE_ITER_EVENT_FORK)
trace_event_follow_fork(tr, enabled);
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 39fd77330aab..17a66d459ee3 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -635,8 +635,9 @@ void trace_graph_return(struct ftrace_graph_ret *trace);
int trace_graph_entry(struct ftrace_graph_ent *trace);
void set_graph_array(struct trace_array *tr);
-void tracing_start_cmdline_record(void);
-void tracing_stop_cmdline_record(void);
+void tracing_alloc_tgid_map(void);
+void tracing_start_taskinfo_record(bool cmd, bool tgid);
+void tracing_stop_taskinfo_record(bool cmd, bool tgid);
int register_tracer(struct tracer *type);
int is_tracing_stopped(void);
@@ -697,6 +698,7 @@ static inline void __trace_stack(struct trace_array *tr, unsigned long flags,
extern u64 ftrace_now(int cpu);
extern void trace_find_cmdline(int pid, char comm[]);
+extern unsigned int trace_find_tgid(unsigned int pid);
extern void trace_event_follow_fork(struct trace_array *tr, bool enable);
#ifdef CONFIG_DYNAMIC_FTRACE
@@ -1107,6 +1109,7 @@ extern int trace_get_user(struct trace_parser *parser, const char __user *ubuf,
C(CONTEXT_INFO, "context-info"), /* Print pid/cpu/time */ \
C(LATENCY_FMT, "latency-format"), \
C(RECORD_CMD, "record-cmd"), \
+ C(RECORD_TGID, "record-tgid"), \
C(OVERWRITE, "overwrite"), \
C(STOP_ON_FREE, "disable_on_free"), \
C(IRQ_INFO, "irq-info"), \
@@ -1423,6 +1426,8 @@ struct ftrace_event_field *
trace_find_event_field(struct trace_event_call *call, char *name);
extern void trace_event_enable_cmd_record(bool enable);
+extern void trace_event_enable_tgid_record(bool enable);
+
extern int event_trace_add_tracer(struct dentry *parent, struct trace_array *tr);
extern int event_trace_del_tracer(struct trace_array *tr);
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index e7973e10398c..c71d6223e667 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -321,6 +321,16 @@ int trace_event_reg(struct trace_event_call *call,
}
EXPORT_SYMBOL_GPL(trace_event_reg);
+static bool trace_event_file_cmd_record(struct trace_event_file *file)
+{
+ return !!(file->flags & EVENT_FILE_FL_RECORDED_CMD);
+}
+
+static bool trace_event_file_tgid_record(struct trace_event_file *file)
+{
+ return !!(file->flags & EVENT_FILE_FL_RECORDED_TGID);
+}
+
void trace_event_enable_cmd_record(bool enable)
{
struct trace_event_file *file;
@@ -328,21 +338,54 @@ void trace_event_enable_cmd_record(bool enable)
mutex_lock(&event_mutex);
do_for_each_event_file(tr, file) {
+ bool cmd_record = trace_event_file_cmd_record(file);
if (!(file->flags & EVENT_FILE_FL_ENABLED))
continue;
if (enable) {
- tracing_start_cmdline_record();
+ if (cmd_record)
+ continue;
+ tracing_start_taskinfo_record(true, false);
set_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
} else {
- tracing_stop_cmdline_record();
+ if (!cmd_record)
+ continue;
+ tracing_stop_taskinfo_record(true, false);
clear_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
}
} while_for_each_event_file();
mutex_unlock(&event_mutex);
}
+void trace_event_enable_tgid_record(bool enable)
+{
+ struct trace_event_file *file;
+ struct trace_array *tr;
+
+ mutex_lock(&event_mutex);
+ do_for_each_event_file(tr, file) {
+ bool tgid_record = trace_event_file_tgid_record(file);
+
+ if (!(file->flags & EVENT_FILE_FL_ENABLED))
+ continue;
+
+ if (enable) {
+ if (tgid_record)
+ continue;
+ tracing_start_taskinfo_record(false, true);
+ set_bit(EVENT_FILE_FL_RECORDED_TGID_BIT, &file->flags);
+ } else {
+ if (!tgid_record)
+ continue;
+ tracing_stop_taskinfo_record(false, true);
+ clear_bit(EVENT_FILE_FL_RECORDED_TGID_BIT,
+ &file->flags);
+ }
+ } while_for_each_event_file();
+ mutex_unlock(&event_mutex);
+}
+
static int __ftrace_event_enable_disable(struct trace_event_file *file,
int enable, int soft_disable)
{
@@ -351,6 +394,7 @@ static int __ftrace_event_enable_disable(struct trace_event_file *file,
unsigned long file_flags = file->flags;
int ret = 0;
int disable;
+ bool cmd_record, tgid_record;
switch (enable) {
case 0:
@@ -377,10 +421,18 @@ static int __ftrace_event_enable_disable(struct trace_event_file *file,
if (disable && (file->flags & EVENT_FILE_FL_ENABLED)) {
clear_bit(EVENT_FILE_FL_ENABLED_BIT, &file->flags);
- if (file->flags & EVENT_FILE_FL_RECORDED_CMD) {
- tracing_stop_cmdline_record();
- clear_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
- }
+
+ cmd_record = trace_event_file_cmd_record(file);
+ tgid_record = trace_event_file_tgid_record(file);
+
+ tracing_stop_taskinfo_record(cmd_record, tgid_record);
+ if (cmd_record)
+ clear_bit(EVENT_FILE_FL_RECORDED_CMD_BIT,
+ &file->flags);
+ if (tgid_record)
+ clear_bit(EVENT_FILE_FL_RECORDED_TGID_BIT,
+ &file->flags);
+
call->class->reg(call, TRACE_REG_UNREGISTER, file);
}
/* If in SOFT_MODE, just set the SOFT_DISABLE_BIT, else clear it */
@@ -407,18 +459,25 @@ static int __ftrace_event_enable_disable(struct trace_event_file *file,
}
if (!(file->flags & EVENT_FILE_FL_ENABLED)) {
-
/* Keep the event disabled, when going to SOFT_MODE. */
if (soft_disable)
set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags);
- if (tr->trace_flags & TRACE_ITER_RECORD_CMD) {
- tracing_start_cmdline_record();
- set_bit(EVENT_FILE_FL_RECORDED_CMD_BIT, &file->flags);
- }
+ cmd_record = tr->trace_flags & TRACE_ITER_RECORD_CMD;
+ tgid_record = tr->trace_flags & TRACE_ITER_RECORD_TGID;
+
+ tracing_start_taskinfo_record(cmd_record, tgid_record);
+ if (cmd_record)
+ set_bit(EVENT_FILE_FL_RECORDED_CMD_BIT,
+ &file->flags);
+ if (tgid_record)
+ set_bit(EVENT_FILE_FL_RECORDED_TGID_BIT,
+ &file->flags);
+
ret = call->class->reg(call, TRACE_REG_REGISTER, file);
if (ret) {
- tracing_stop_cmdline_record();
+ tracing_stop_taskinfo_record(cmd_record,
+ tgid_record);
pr_info("event trace: Could not enable event "
"%s\n", trace_event_name(call));
break;
diff --git a/kernel/trace/trace_functions.c b/kernel/trace/trace_functions.c
index a3bddbfd0874..05da1e7513f6 100644
--- a/kernel/trace/trace_functions.c
+++ b/kernel/trace/trace_functions.c
@@ -103,7 +103,8 @@ static int function_trace_init(struct trace_array *tr)
tr->trace_buffer.cpu = get_cpu();
put_cpu();
- tracing_start_cmdline_record();
+ tracing_start_taskinfo_record(true, false);
+
tracing_start_function_trace(tr);
return 0;
}
@@ -111,7 +112,7 @@ static int function_trace_init(struct trace_array *tr)
static void function_trace_reset(struct trace_array *tr)
{
tracing_stop_function_trace(tr);
- tracing_stop_cmdline_record();
+ tracing_stop_taskinfo_record(true, false);
ftrace_reset_array_ops(tr);
}
diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c
index d56123cdcc89..3691198b4778 100644
--- a/kernel/trace/trace_functions_graph.c
+++ b/kernel/trace/trace_functions_graph.c
@@ -524,14 +524,14 @@ static int graph_trace_init(struct trace_array *tr)
&trace_graph_entry);
if (ret)
return ret;
- tracing_start_cmdline_record();
+ tracing_start_taskinfo_record(true, false);
return 0;
}
static void graph_trace_reset(struct trace_array *tr)
{
- tracing_stop_cmdline_record();
+ tracing_stop_taskinfo_record(true, false);
unregister_ftrace_graph();
}
diff --git a/kernel/trace/trace_sched_switch.c b/kernel/trace/trace_sched_switch.c
index 4c896a0101bd..8f61897fd6e3 100644
--- a/kernel/trace/trace_sched_switch.c
+++ b/kernel/trace/trace_sched_switch.c
@@ -12,27 +12,30 @@
#include "trace.h"
-static int sched_ref;
+static int sched_cmdline_ref;
+static int sched_tgid_ref;
static DEFINE_MUTEX(sched_register_mutex);
+#define RECORD_CMD BIT(0)
+#define RECORD_TGID BIT(1)
+
static void
probe_sched_switch(void *ignore, bool preempt,
struct task_struct *prev, struct task_struct *next)
{
- if (unlikely(!sched_ref))
- return;
+ struct task_struct *tasks[2] = { prev, next };
- tracing_record_cmdline(prev);
- tracing_record_cmdline(next);
+ tracing_record_taskinfo(tasks, 2,
+ (sched_cmdline_ref != 0),
+ (sched_tgid_ref != 0));
}
static void
probe_sched_wakeup(void *ignore, struct task_struct *wakee)
{
- if (unlikely(!sched_ref))
- return;
-
- tracing_record_cmdline(current);
+ tracing_record_taskinfo_single(current,
+ (sched_cmdline_ref != 0),
+ (sched_tgid_ref != 0));
}
static int tracing_sched_register(void)
@@ -75,28 +78,58 @@ static void tracing_sched_unregister(void)
unregister_trace_sched_wakeup(probe_sched_wakeup, NULL);
}
-static void tracing_start_sched_switch(void)
+static void tracing_start_sched_switch(int flags)
{
+ bool sched_register;
mutex_lock(&sched_register_mutex);
- if (!(sched_ref++))
+ sched_register = (!sched_cmdline_ref && !sched_tgid_ref);
+
+ if (flags & RECORD_CMD)
+ sched_cmdline_ref++;
+
+ if (flags & RECORD_TGID)
+ sched_tgid_ref++;
+
+ if (sched_tgid_ref == 1)
+ tracing_alloc_tgid_map();
+
+ if (sched_register && (sched_cmdline_ref || sched_tgid_ref))
tracing_sched_register();
mutex_unlock(&sched_register_mutex);
}
-static void tracing_stop_sched_switch(void)
+static void tracing_stop_sched_switch(int flags)
{
mutex_lock(&sched_register_mutex);
- if (!(--sched_ref))
+ if (flags & RECORD_CMD)
+ sched_cmdline_ref--;
+
+ if (flags & RECORD_TGID)
+ sched_tgid_ref--;
+
+ if (!sched_cmdline_ref && !sched_tgid_ref)
tracing_sched_unregister();
mutex_unlock(&sched_register_mutex);
}
-void tracing_start_cmdline_record(void)
+void tracing_start_taskinfo_record(bool cmdline, bool tgid)
{
- tracing_start_sched_switch();
+ int flags;
+
+ if (!cmdline && !tgid)
+ return;
+ flags = (tgid ? RECORD_TGID : 0);
+ flags |= (cmdline ? RECORD_CMD : 0);
+ tracing_start_sched_switch(flags);
}
-void tracing_stop_cmdline_record(void)
+void tracing_stop_taskinfo_record(bool cmdline, bool tgid)
{
- tracing_stop_sched_switch();
+ int flags;
+
+ if (!cmdline && !tgid)
+ return;
+ flags = (tgid ? RECORD_TGID : 0);
+ flags |= (cmdline ? RECORD_CMD : 0);
+ tracing_stop_sched_switch(flags);
}
diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c
index cb917cebae29..83029d94d643 100644
--- a/kernel/trace/trace_selftest.c
+++ b/kernel/trace/trace_selftest.c
@@ -770,7 +770,7 @@ trace_selftest_startup_function_graph(struct tracer *trace,
warn_failed_init_tracer(trace, ret);
goto out;
}
- tracing_start_cmdline_record();
+ tracing_start_taskinfo_record(true, false);
/* Sleep for a 1/10 of a second */
msleep(100);
--
2.13.0.506.g27d5fe0cd-goog
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [RFC v2 3/4] tracing: Add support for display of tgid in trace output
2017-06-04 4:03 [RFC v2 0/4] tracing: Add support to record and display tgid of tasks Joel Fernandes
2017-06-04 4:03 ` [RFC v2 1/4] tracing: Remove unused declaration of trace_stop_cmdline_recording Joel Fernandes
2017-06-04 4:03 ` [RFC v2 2/4] tracing: Add support for recording tgid of tasks Joel Fernandes
@ 2017-06-04 4:03 ` Joel Fernandes
2017-06-04 4:03 ` [RFC v2 4/4] tracing/ftrace: Add support to record and display tgid Joel Fernandes
3 siblings, 0 replies; 6+ messages in thread
From: Joel Fernandes @ 2017-06-04 4:03 UTC (permalink / raw)
To: linux-kernel; +Cc: Joel Fernandes, kernel-team, Steven Rostedt, Ingo Molnar
Earlier patches introduced ability to record the tgid using the 'record-tgid'
option. Here we read the tgid and output it if the option is enabled.
Cc: kernel-team@android.com
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Joel Fernandes <joelaf@google.com>
---
kernel/trace/trace.c | 47 ++++++++++++++++++++++++++++++++-------------
kernel/trace/trace_output.c | 9 +++++++++
2 files changed, 43 insertions(+), 13 deletions(-)
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 7be21ae4f0a8..5883498754a1 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -3294,23 +3294,42 @@ static void print_event_info(struct trace_buffer *buf, struct seq_file *m)
seq_puts(m, "#\n");
}
-static void print_func_help_header(struct trace_buffer *buf, struct seq_file *m)
+static void print_func_help_header(struct trace_buffer *buf, struct seq_file *m,
+ unsigned int flags)
{
print_event_info(buf, m);
- seq_puts(m, "# TASK-PID CPU# TIMESTAMP FUNCTION\n"
- "# | | | | |\n");
+ if (!(flags & TRACE_ITER_RECORD_TGID)) {
+ seq_puts(m, "# TASK-PID CPU# TIMESTAMP FUNCTION\n"
+ "# | | | | |\n");
+ return;
+ }
+
+ seq_puts(m, "# TASK-PID CPU# TGID TIMESTAMP FUNCTION\n"
+ "# | | | | | |\n");
}
-static void print_func_help_header_irq(struct trace_buffer *buf, struct seq_file *m)
+static void print_func_help_header_irq(struct trace_buffer *buf, struct seq_file *m,
+ unsigned int flags)
{
print_event_info(buf, m);
- seq_puts(m, "# _-----=> irqs-off\n"
- "# / _----=> need-resched\n"
- "# | / _---=> hardirq/softirq\n"
- "# || / _--=> preempt-depth\n"
- "# ||| / delay\n"
- "# TASK-PID CPU# |||| TIMESTAMP FUNCTION\n"
- "# | | | |||| | |\n");
+ if (!(flags & TRACE_ITER_RECORD_TGID)) {
+ seq_puts(m, "# _-----=> irqs-off\n"
+ "# / _----=> need-resched\n"
+ "# | / _---=> hardirq/softirq\n"
+ "# || / _--=> preempt-depth\n"
+ "# ||| / delay\n"
+ "# TASK-PID CPU# |||| TIMESTAMP FUNCTION\n"
+ "# | | | |||| | |\n");
+ return;
+ }
+
+ seq_puts(m, "# _-----=> irqs-off\n"
+ "# / _----=> need-resched\n"
+ "# | / _---=> hardirq/softirq\n"
+ "# || / _--=> preempt-depth\n"
+ "# ||| / delay\n"
+ "# TASK-PID CPU# TGID |||| TIMESTAMP FUNCTION\n"
+ "# | | | | |||| | |\n");
}
void
@@ -3626,9 +3645,11 @@ void trace_default_header(struct seq_file *m)
} else {
if (!(trace_flags & TRACE_ITER_VERBOSE)) {
if (trace_flags & TRACE_ITER_IRQ_INFO)
- print_func_help_header_irq(iter->trace_buffer, m);
+ print_func_help_header_irq(iter->trace_buffer,
+ m, trace_flags);
else
- print_func_help_header(iter->trace_buffer, m);
+ print_func_help_header(iter->trace_buffer, m,
+ trace_flags);
}
}
}
diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
index 08f9bab8089e..55c743295874 100644
--- a/kernel/trace/trace_output.c
+++ b/kernel/trace/trace_output.c
@@ -587,6 +587,15 @@ int trace_print_context(struct trace_iterator *iter)
trace_seq_printf(s, "%16s-%-5d [%03d] ",
comm, entry->pid, iter->cpu);
+ if (tr->trace_flags & TRACE_ITER_RECORD_TGID) {
+ unsigned int tgid = trace_find_tgid(entry->pid);
+
+ if (!tgid)
+ trace_seq_printf(s, "(-----) ");
+ else
+ trace_seq_printf(s, "(%5d) ", tgid);
+ }
+
if (tr->trace_flags & TRACE_ITER_IRQ_INFO)
trace_print_lat_fmt(s, entry);
--
2.13.0.506.g27d5fe0cd-goog
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [RFC v2 4/4] tracing/ftrace: Add support to record and display tgid
2017-06-04 4:03 [RFC v2 0/4] tracing: Add support to record and display tgid of tasks Joel Fernandes
` (2 preceding siblings ...)
2017-06-04 4:03 ` [RFC v2 3/4] tracing: Add support for display of tgid in trace output Joel Fernandes
@ 2017-06-04 4:03 ` Joel Fernandes
3 siblings, 0 replies; 6+ messages in thread
From: Joel Fernandes @ 2017-06-04 4:03 UTC (permalink / raw)
To: linux-kernel; +Cc: Joel Fernandes, kernel-team, Steven Rostedt, Ingo Molnar
Make function tracer able to record tgid if/when record-tgid is enabled.
Cc: kernel-team@android.com
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Joel Fernandes <joelaf@google.com>
---
kernel/trace/trace_functions.c | 23 +++++++++++++++++++++--
1 file changed, 21 insertions(+), 2 deletions(-)
diff --git a/kernel/trace/trace_functions.c b/kernel/trace/trace_functions.c
index 05da1e7513f6..290a7a80abf2 100644
--- a/kernel/trace/trace_functions.c
+++ b/kernel/trace/trace_functions.c
@@ -27,6 +27,7 @@ static void
function_stack_trace_call(unsigned long ip, unsigned long parent_ip,
struct ftrace_ops *op, struct pt_regs *pt_regs);
static struct tracer_flags func_flags;
+static bool tgid_recorded;
/* Our option */
enum {
@@ -103,7 +104,8 @@ static int function_trace_init(struct trace_array *tr)
tr->trace_buffer.cpu = get_cpu();
put_cpu();
- tracing_start_taskinfo_record(true, false);
+ tgid_recorded = tr->trace_flags & TRACE_ITER_RECORD_TGID;
+ tracing_start_taskinfo_record(true, tgid_recorded);
tracing_start_function_trace(tr);
return 0;
@@ -112,7 +114,8 @@ static int function_trace_init(struct trace_array *tr)
static void function_trace_reset(struct trace_array *tr)
{
tracing_stop_function_trace(tr);
- tracing_stop_taskinfo_record(true, false);
+ tracing_stop_taskinfo_record(true, tgid_recorded);
+ tgid_recorded = false;
ftrace_reset_array_ops(tr);
}
@@ -253,6 +256,21 @@ func_set_flag(struct trace_array *tr, u32 old_flags, u32 bit, int set)
return 0;
}
+static int
+func_tracer_flag_changed(struct trace_array *tr, unsigned int mask,
+ int enabled)
+{
+ if (mask == TRACE_ITER_RECORD_TGID) {
+ tgid_recorded = !!enabled;
+ if (enabled)
+ tracing_start_taskinfo_record(false, true);
+ else
+ tracing_stop_taskinfo_record(false, true);
+ }
+
+ return 0;
+}
+
static struct tracer function_trace __tracer_data =
{
.name = "function",
@@ -261,6 +279,7 @@ static struct tracer function_trace __tracer_data =
.start = function_trace_start,
.flags = &func_flags,
.set_flag = func_set_flag,
+ .flag_changed = func_tracer_flag_changed,
.allow_instances = true,
#ifdef CONFIG_FTRACE_SELFTEST
.selftest = trace_selftest_startup_function,
--
2.13.0.506.g27d5fe0cd-goog
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [RFC v2 2/4] tracing: Add support for recording tgid of tasks
2017-06-04 4:03 ` [RFC v2 2/4] tracing: Add support for recording tgid of tasks Joel Fernandes
@ 2017-06-04 5:44 ` Joel Fernandes
0 siblings, 0 replies; 6+ messages in thread
From: Joel Fernandes @ 2017-06-04 5:44 UTC (permalink / raw)
To: LKML
Cc: Joel Fernandes, kernel-team, Steven Rostedt, Ingo Molnar,
Jens Axboe, open list:BLOCK LAYER
Some minor things that I will rework in next rev after spending some
more time on it:
On Sat, Jun 3, 2017 at 9:03 PM, Joel Fernandes <joelaf@google.com> wrote:
[..]
> @@ -463,7 +469,7 @@ int trace_set_clr_event(const char *system, const char *event, int set);
> #define event_trace_printk(ip, fmt, args...) \
> do { \
> __trace_printk_check_format(fmt, ##args); \
> - tracing_record_cmdline(current); \
> + tracing_record_taskinfo_single(current, true, false); \
> if (__builtin_constant_p(fmt)) { \
> static const char *trace_printk_fmt \
> __attribute__((section("__trace_printk_fmt"))) = \
> diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
> index 193c5f5e3f79..d7394cdf899e 100644
> --- a/kernel/trace/blktrace.c
> +++ b/kernel/trace/blktrace.c
> @@ -236,7 +236,7 @@ static void __blk_add_trace(struct blk_trace *bt, sector_t sector, int bytes,
> cpu = raw_smp_processor_id();
>
> if (blk_tracer) {
> - tracing_record_cmdline(current);
> + tracing_record_taskinfo_single(current, true, false);
I think I will try to preserve the existing API so that existing users
aren't bothered much.
>
> buffer = blk_tr->trace_buffer.buffer;
> pc = preempt_count();
> diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
> index 63deff9cdf2c..7be21ae4f0a8 100644
> --- a/kernel/trace/trace.c
> +++ b/kernel/trace/trace.c
> @@ -87,7 +87,7 @@ dummy_set_flag(struct trace_array *tr, u32 old_flags, u32 bit, int set)
> * tracing is active, only save the comm when a trace event
> * occurred.
> */
> -static DEFINE_PER_CPU(bool, trace_cmdline_save);
> +static DEFINE_PER_CPU(bool, trace_taskinfo_save);
>
> /*
> * Kill all tracing for good (never come back).
> @@ -790,7 +790,7 @@ EXPORT_SYMBOL_GPL(tracing_on);
> static __always_inline void
> __buffer_unlock_commit(struct ring_buffer *buffer, struct ring_buffer_event *event)
> {
> - __this_cpu_write(trace_cmdline_save, true);
> + __this_cpu_write(trace_taskinfo_save, true);
>
> /* If this is the temp buffer, we need to commit fully */
> if (this_cpu_read(trace_buffered_event) == event) {
> @@ -1709,6 +1709,15 @@ void tracing_reset_all_online_cpus(void)
> }
> }
>
> +static unsigned int *tgid_map;
> +
> +void tracing_alloc_tgid_map(void)
> +{
> + tgid_map = kzalloc((PID_MAX_DEFAULT + 1) * sizeof(*tgid_map),
> + GFP_KERNEL);
> + WARN_ONCE(!tgid_map, "Allocation of tgid_map failed\n");
I should check if tgid_map is already allocated or there's a chance of
re-allocating.
Looking forward to any other comments...
thanks,
-Joel
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2017-06-04 5:44 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
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2017-06-04 4:03 [RFC v2 0/4] tracing: Add support to record and display tgid of tasks Joel Fernandes
2017-06-04 4:03 ` [RFC v2 1/4] tracing: Remove unused declaration of trace_stop_cmdline_recording Joel Fernandes
2017-06-04 4:03 ` [RFC v2 2/4] tracing: Add support for recording tgid of tasks Joel Fernandes
2017-06-04 5:44 ` Joel Fernandes
2017-06-04 4:03 ` [RFC v2 3/4] tracing: Add support for display of tgid in trace output Joel Fernandes
2017-06-04 4:03 ` [RFC v2 4/4] tracing/ftrace: Add support to record and display tgid Joel Fernandes
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