From: Zhaolei There are many clock sources for the tracing system but we can only enable/disable one at a time with the trace/options file. We can move the setting of clock-source out of options and add a separate file for it: # cat trace_clock [local] global # echo global > trace_clock # cat trace_clock local [global] Signed-off-by: Zhao Lei LKML-Reference: <4A939D08.6050604@cn.fujitsu.com> Signed-off-by: Steven Rostedt --- kernel/trace/trace.c | 92 ++++++++++++++++++++++++++++++++++++++++--------- kernel/trace/trace.h | 7 ++-- 2 files changed, 79 insertions(+), 20 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 8ac2043..63dbc7f 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -323,12 +323,21 @@ static const char *trace_options[] = { "printk-msg-only", "context-info", "latency-format", - "global-clock", "sleep-time", "graph-time", NULL }; +static struct { + u64 (*func)(void); + const char *name; +} trace_clocks[] = { + { trace_clock_local, "local" }, + { trace_clock_global, "global" }, +}; + +int trace_clock_id; + /* * ftrace_max_lock is used to protect the swapping of buffers * when taking a max snapshot. The buffers themselves are @@ -2159,22 +2168,6 @@ static void set_tracer_flags(unsigned int mask, int enabled) trace_flags |= mask; else trace_flags &= ~mask; - - if (mask == TRACE_ITER_GLOBAL_CLK) { - u64 (*func)(void); - - if (enabled) - func = trace_clock_global; - else - func = trace_clock_local; - - mutex_lock(&trace_types_lock); - ring_buffer_set_clock(global_trace.buffer, func); - - if (max_tr.buffer) - ring_buffer_set_clock(max_tr.buffer, func); - mutex_unlock(&trace_types_lock); - } } static ssize_t @@ -3142,6 +3135,62 @@ tracing_mark_write(struct file *filp, const char __user *ubuf, return cnt; } +static ssize_t tracing_clock_read(struct file *filp, char __user *ubuf, + size_t cnt, loff_t *ppos) +{ + char buf[64]; + int bufiter = 0; + int i; + + for (i = 0; i < ARRAY_SIZE(trace_clocks); i++) + bufiter += snprintf(buf + bufiter, sizeof(buf) - bufiter, + "%s%s%s%s", i ? " " : "", + i == trace_clock_id ? "[" : "", trace_clocks[i].name, + i == trace_clock_id ? "]" : ""); + bufiter += snprintf(buf + bufiter, sizeof(buf) - bufiter, "\n"); + + return simple_read_from_buffer(ubuf, cnt, ppos, buf, bufiter); +} + +static ssize_t tracing_clock_write(struct file *filp, const char __user *ubuf, + size_t cnt, loff_t *fpos) +{ + char buf[64]; + const char *clockstr; + int i; + + if (cnt >= sizeof(buf)) + return -EINVAL; + + if (copy_from_user(&buf, ubuf, cnt)) + return -EFAULT; + + buf[cnt] = 0; + + clockstr = strstrip(buf); + + for (i = 0; i < ARRAY_SIZE(trace_clocks); i++) { + if (strcmp(trace_clocks[i].name, clockstr) == 0) + break; + } + if (i == ARRAY_SIZE(trace_clocks)) + return -EINVAL; + + trace_clock_id = i; + + mutex_lock(&trace_types_lock); + + ring_buffer_set_clock(global_trace.buffer, trace_clocks[i].func); + if (max_tr.buffer) + ring_buffer_set_clock(max_tr.buffer, trace_clocks[i].func); + + mutex_unlock(&trace_types_lock); + + *fpos += cnt; + + return cnt; +} + static const struct file_operations tracing_max_lat_fops = { .open = tracing_open_generic, .read = tracing_max_lat_read, @@ -3179,6 +3228,12 @@ static const struct file_operations tracing_mark_fops = { .write = tracing_mark_write, }; +static const struct file_operations trace_clock_fops = { + .open = tracing_open_generic, + .read = tracing_clock_read, + .write = tracing_clock_write, +}; + struct ftrace_buffer_info { struct trace_array *tr; void *spare; @@ -3918,6 +3973,9 @@ static __init int tracer_init_debugfs(void) trace_create_file("saved_cmdlines", 0444, d_tracer, NULL, &tracing_saved_cmdlines_fops); + trace_create_file("trace_clock", 0644, d_tracer, NULL, + &trace_clock_fops); + #ifdef CONFIG_DYNAMIC_FTRACE trace_create_file("dyn_ftrace_total_info", 0444, d_tracer, &ftrace_update_tot_cnt, &tracing_dyn_info_fops); diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 64dda57..654fd65 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -568,6 +568,8 @@ trace_vprintk(unsigned long ip, const char *fmt, va_list args); extern unsigned long trace_flags; +extern int trace_clock_id; + /* Standard output formatting function used for function return traces */ #ifdef CONFIG_FUNCTION_GRAPH_TRACER extern enum print_line_t print_graph_function(struct trace_iterator *iter); @@ -656,9 +658,8 @@ enum trace_iterator_flags { TRACE_ITER_PRINTK_MSGONLY = 0x10000, TRACE_ITER_CONTEXT_INFO = 0x20000, /* Print pid/cpu/time */ TRACE_ITER_LATENCY_FMT = 0x40000, - TRACE_ITER_GLOBAL_CLK = 0x80000, - TRACE_ITER_SLEEP_TIME = 0x100000, - TRACE_ITER_GRAPH_TIME = 0x200000, + TRACE_ITER_SLEEP_TIME = 0x80000, + TRACE_ITER_GRAPH_TIME = 0x100000, }; /* -- 1.6.3.3 -- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/