lkml.org 
[lkml]   [2009]   [Jul]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 1/6] tracing: Simplify print_graph_cpu()
Date
From: Lai Jiangshan <laijs@cn.fujitsu.com>

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: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <4A6EEE5E.2000001@cn.fujitsu.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
---
kernel/trace/trace_functions_graph.c | 30 ++++--------------------------
1 files changed, 4 insertions(+), 26 deletions(-)
diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c
index abf7c4a..e30472d 100644
--- a/kernel/trace/trace_functions_graph.c
+++ b/kernel/trace/trace_functions_graph.c
@@ -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);
}

--
1.6.2.3


\
 
 \ /
  Last update: 2009-07-29 19:19    [from the cache]
©2003-2011 Jasper Spaans