Commit 0c9e6f63 authored by Lai Jiangshan's avatar Lai Jiangshan Committed by Frederic Weisbecker

tracing: Simplify print_graph_cpu()

print_graph_cpu() is little over-designed.

And "log10_all" may be wrong when there are holes in cpu_online_mask:
the max online cpu id > cpumask_weight(cpu_online_mask)

So change it by using a static column length for the cpu matching
nr_cpu_ids number of decimal characters.
Signed-off-by: default avatarLai Jiangshan <laijs@cn.fujitsu.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <4A6EEE5E.2000001@cn.fujitsu.com>
Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
parent 1f9963cb
......@@ -183,43 +183,19 @@ static void graph_trace_reset(struct trace_array *tr)
unregister_ftrace_graph();
}
static inline int log10_cpu(int nb)
{
if (nb / 100)
return 3;
if (nb / 10)
return 2;
return 1;
}
static int max_bytes_for_cpu;
static enum print_line_t
print_graph_cpu(struct trace_seq *s, int cpu)
{
int i;
int ret;
int log10_this = log10_cpu(cpu);
int log10_all = log10_cpu(cpumask_weight(cpu_online_mask));
/*
* Start with a space character - to make it stand out
* to the right a bit when trace output is pasted into
* email:
*/
ret = trace_seq_printf(s, " ");
/*
* Tricky - we space the CPU field according to the max
* number of online CPUs. On a 2-cpu system it would take
* a maximum of 1 digit - on a 128 cpu system it would
* take up to 3 digits:
*/
for (i = 0; i < log10_all - log10_this; i++) {
ret = trace_seq_printf(s, " ");
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
}
ret = trace_seq_printf(s, "%d) ", cpu);
ret = trace_seq_printf(s, " %*d) ", max_bytes_for_cpu, cpu);
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
......@@ -919,6 +895,8 @@ static struct tracer graph_trace __read_mostly = {
static __init int init_graph_trace(void)
{
max_bytes_for_cpu = snprintf(NULL, 0, "%d", nr_cpu_ids - 1);
return register_tracer(&graph_trace);
}
......
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment