From 0c5363f6a0a89952b0d0072ff4e4c3bd042add9a Mon Sep 17 00:00:00 2001 From: Jamie Gennis Date: Wed, 21 Nov 2012 15:04:25 -0800 Subject: [PATCH] trace: Add an option to show tgids in trace output The tgids are tracked along side the saved_cmdlines tracking, and can be included in trace output by enabling the 'print-tgid' trace option. This is useful when doing post-processing of the trace data, as it allows events to be grouped by tgid. Change-Id: I52ed04c3a8ca7fddbb868b792ce5d21ceb76250e Signed-off-by: Jamie Gennis --- kernel/trace/trace.c | 104 ++++++++++++++++++++++++++++++++++-- kernel/trace/trace.h | 2 + kernel/trace/trace_output.c | 18 ++++++- 3 files changed, 117 insertions(+), 7 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index e71a8be4a6ee..28f007ac9938 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -636,6 +636,7 @@ static const char *trace_options[] = { "irq-info", "markers", "function-trace", + "print-tgid", NULL }; @@ -1151,6 +1152,7 @@ void tracing_reset_all_online_cpus(void) static unsigned map_pid_to_cmdline[PID_MAX_DEFAULT+1]; static unsigned map_cmdline_to_pid[SAVED_CMDLINES]; static char saved_cmdlines[SAVED_CMDLINES][TASK_COMM_LEN]; +static unsigned saved_tgids[SAVED_CMDLINES]; static int cmdline_idx; static arch_spinlock_t trace_cmdline_lock = __ARCH_SPIN_LOCK_UNLOCKED; @@ -1354,6 +1356,7 @@ static void trace_save_cmdline(struct task_struct *tsk) } memcpy(&saved_cmdlines[idx], tsk->comm, TASK_COMM_LEN); + saved_tgids[idx] = tsk->tgid; arch_spin_unlock(&trace_cmdline_lock); } @@ -1389,6 +1392,25 @@ void trace_find_cmdline(int pid, char comm[]) preempt_enable(); } +int trace_find_tgid(int pid) +{ + unsigned map; + int tgid; + + preempt_disable(); + arch_spin_lock(&trace_cmdline_lock); + map = map_pid_to_cmdline[pid]; + if (map != NO_CMDLINE_MAP) + tgid = saved_tgids[map]; + else + tgid = -1; + + arch_spin_unlock(&trace_cmdline_lock); + preempt_enable(); + + return tgid; +} + void tracing_record_cmdline(struct task_struct *tsk) { if (atomic_read(&trace_record_cmdline_disabled) || !tracing_is_on()) @@ -2345,6 +2367,13 @@ static void print_func_help_header(struct trace_buffer *buf, struct seq_file *m) seq_puts(m, "# | | | | |\n"); } +static void print_func_help_header_tgid(struct trace_buffer *buf, struct seq_file *m) +{ + print_event_info(buf, m); + seq_puts(m, "# TASK-PID TGID CPU# TIMESTAMP FUNCTION\n"); + seq_puts(m, "# | | | | | |\n"); +} + static void print_func_help_header_irq(struct trace_buffer *buf, struct seq_file *m) { print_event_info(buf, m); @@ -2357,6 +2386,18 @@ static void print_func_help_header_irq(struct trace_buffer *buf, struct seq_file seq_puts(m, "# | | | |||| | |\n"); } +static void print_func_help_header_irq_tgid(struct trace_buffer *buf, struct seq_file *m) +{ + print_event_info(buf, m); + seq_puts(m, "# _-----=> irqs-off\n"); + seq_puts(m, "# / _----=> need-resched\n"); + seq_puts(m, "# | / _---=> hardirq/softirq\n"); + seq_puts(m, "# || / _--=> preempt-depth\n"); + seq_puts(m, "# ||| / delay\n"); + seq_puts(m, "# TASK-PID TGID CPU# |||| TIMESTAMP FUNCTION\n"); + seq_puts(m, "# | | | | |||| | |\n"); +} + void print_trace_header(struct seq_file *m, struct trace_iterator *iter) { @@ -2657,9 +2698,15 @@ 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); + if (trace_flags & TRACE_ITER_TGID) + print_func_help_header_irq_tgid(iter->trace_buffer, m); + else + print_func_help_header_irq(iter->trace_buffer, m); else - print_func_help_header(iter->trace_buffer, m); + if (trace_flags & TRACE_ITER_TGID) + print_func_help_header_tgid(iter->trace_buffer, m); + else + print_func_help_header(iter->trace_buffer, m); } } } @@ -3449,9 +3496,53 @@ tracing_saved_cmdlines_read(struct file *file, char __user *ubuf, } static const struct file_operations tracing_saved_cmdlines_fops = { - .open = tracing_open_generic, - .read = tracing_saved_cmdlines_read, - .llseek = generic_file_llseek, + .open = tracing_open_generic, + .read = tracing_saved_cmdlines_read, + .llseek = generic_file_llseek, +}; + +static ssize_t +tracing_saved_tgids_read(struct file *file, char __user *ubuf, + size_t cnt, loff_t *ppos) +{ + char *file_buf; + char *buf; + int len = 0; + int pid; + int i; + + file_buf = kmalloc(SAVED_CMDLINES*(16+1+16), GFP_KERNEL); + if (!file_buf) + return -ENOMEM; + + buf = file_buf; + + for (i = 0; i < SAVED_CMDLINES; i++) { + int tgid; + int r; + + pid = map_cmdline_to_pid[i]; + if (pid == -1 || pid == NO_CMDLINE_MAP) + continue; + + tgid = trace_find_tgid(pid); + r = sprintf(buf, "%d %d\n", pid, tgid); + buf += r; + len += r; + } + + len = simple_read_from_buffer(ubuf, cnt, ppos, + file_buf, len); + + kfree(file_buf); + + return len; +} + +static const struct file_operations tracing_saved_tgids_fops = { + .open = tracing_open_generic, + .read = tracing_saved_tgids_read, + .llseek = generic_file_llseek, }; static ssize_t @@ -5939,6 +6030,9 @@ init_tracer_debugfs(struct trace_array *tr, struct dentry *d_tracer) trace_create_file("trace_marker", 0220, d_tracer, tr, &tracing_mark_fops); + trace_create_file("saved_tgids", 0444, d_tracer, + tr, &tracing_saved_tgids_fops); + trace_create_file("trace_clock", 0644, d_tracer, tr, &trace_clock_fops); diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 20572ed88c5c..6c42f187592c 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -648,6 +648,7 @@ static inline void __trace_stack(struct trace_array *tr, unsigned long flags, extern cycle_t ftrace_now(int cpu); extern void trace_find_cmdline(int pid, char comm[]); +extern int trace_find_tgid(int pid); #ifdef CONFIG_DYNAMIC_FTRACE extern unsigned long ftrace_update_tot_cnt; @@ -861,6 +862,7 @@ enum trace_iterator_flags { TRACE_ITER_IRQ_INFO = 0x800000, TRACE_ITER_MARKERS = 0x1000000, TRACE_ITER_FUNCTION = 0x2000000, + TRACE_ITER_TGID = 0x4000000, }; /* diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c index bb922d9ee51b..31994d2845ea 100644 --- a/kernel/trace/trace_output.c +++ b/kernel/trace/trace_output.c @@ -702,11 +702,25 @@ int trace_print_context(struct trace_iterator *iter) unsigned long secs, usec_rem; char comm[TASK_COMM_LEN]; int ret; + int tgid; trace_find_cmdline(entry->pid, comm); - ret = trace_seq_printf(s, "%16s-%-5d [%03d] ", - comm, entry->pid, iter->cpu); + ret = trace_seq_printf(s, "%16s-%-5d ", comm, entry->pid); + if (!ret) + return 0; + + if (trace_flags & TRACE_ITER_TGID) { + tgid = trace_find_tgid(entry->pid); + if (tgid < 0) + ret = trace_seq_puts(s, "(-----) "); + else + ret = trace_seq_printf(s, "(%5d) ", tgid); + if (!ret) + return 0; + } + + ret = trace_seq_printf(s, "[%03d] ", iter->cpu); if (!ret) return 0; -- 2.34.1