Messages in this thread | | | Date | Tue, 28 Jul 2009 17:53:24 +0200 | From | Frederic Weisbecker <> | Subject | Re: [PATCH] tracing: simplify print_graph_cpu() |
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On Tue, Jul 28, 2009 at 08:26:06PM +0800, Lai Jiangshan wrote: > > 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) > > Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> > --- > 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);
Nice trick :-)
Queued for .32, thanks!
> + > return register_tracer(&graph_trace); > } > > > > >
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