2019-06-17 09:13:53

by Leo Yan

Subject: [PATCH 1/2] perf trace: Use pr_debug() instead of fprintf() for logging

In the function trace__syscall_info(), it explicitly checks verbose
level and print out log with fprintf(). Actually, we can use
pr_debug() to do the same thing for debug logging.

This patch uses pr_debug() instead of fprintf() for debug logging; it
includes a minor fixing for 'space before tab in indent', which
dismisses git warning when apply it.

Signed-off-by: Leo Yan <[email protected]>
---
tools/perf/builtin-trace.c | 21 +++++++++------------
1 file changed, 9 insertions(+), 12 deletions(-)

diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
index bd1f00e7a2eb..5cd74651db4c 100644
--- a/tools/perf/builtin-trace.c
+++ b/tools/perf/builtin-trace.c
@@ -1760,12 +1760,11 @@ static struct syscall *trace__syscall_info(struct trace *trace,
* grep "NR -1 " /t/trace_pipe
*
* After generating some load on the machine.
- */
- if (verbose > 1) {
- static u64 n;
- fprintf(trace->output, "Invalid syscall %d id, skipping (%s, %" PRIu64 ") ...\n",
- id, perf_evsel__name(evsel), ++n);
- }
+ */
+ static u64 n;
+
+ pr_debug("Invalid syscall %d id, skipping (%s, %" PRIu64 ")\n",
+ id, perf_evsel__name(evsel), ++n);
return NULL;
}

@@ -1779,12 +1778,10 @@ static struct syscall *trace__syscall_info(struct trace *trace,
return &trace->syscalls.table[id];

out_cant_read:
- if (verbose > 0) {
- fprintf(trace->output, "Problems reading syscall %d", id);
- if (id <= trace->syscalls.max && trace->syscalls.table[id].name != NULL)
- fprintf(trace->output, "(%s)", trace->syscalls.table[id].name);
- fputs(" information\n", trace->output);
- }
+ pr_debug("Problems reading syscall %d", id);
+ if (id <= trace->syscalls.max && trace->syscalls.table[id].name != NULL)
+ pr_debug("(%s)", trace->syscalls.table[id].name);
+ pr_debug(" information\n");
return NULL;
}

--
2.17.1

2019-06-17 15:24:50

by Arnaldo Carvalho de Melo

Subject: Re: [PATCH 1/2] perf trace: Use pr_debug() instead of fprintf() for logging

Em Mon, Jun 17, 2019 at 05:11:39PM +0800, Leo Yan escreveu:
> In the function trace__syscall_info(), it explicitly checks verbose
> level and print out log with fprintf(). Actually, we can use
> pr_debug() to do the same thing for debug logging.
>
> This patch uses pr_debug() instead of fprintf() for debug logging; it
> includes a minor fixing for 'space before tab in indent', which
> dismisses git warning when apply it.

But those are not fprintf(stdout,), they explicitely redirect to the
output file that the user may have specified using 'perf trace --output
filename.trace' :-)

- Arnaldo

> Signed-off-by: Leo Yan <[email protected]>
> ---
> tools/perf/builtin-trace.c | 21 +++++++++------------
> 1 file changed, 9 insertions(+), 12 deletions(-)
>
> diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
> index bd1f00e7a2eb..5cd74651db4c 100644
> --- a/tools/perf/builtin-trace.c
> +++ b/tools/perf/builtin-trace.c
> @@ -1760,12 +1760,11 @@ static struct syscall *trace__syscall_info(struct trace *trace,
> * grep "NR -1 " /t/trace_pipe
> *
> * After generating some load on the machine.
> - */
> - if (verbose > 1) {
> - static u64 n;
> - fprintf(trace->output, "Invalid syscall %d id, skipping (%s, %" PRIu64 ") ...\n",
> - id, perf_evsel__name(evsel), ++n);
> - }
> + */
> + static u64 n;
> +
> + pr_debug("Invalid syscall %d id, skipping (%s, %" PRIu64 ")\n",
> + id, perf_evsel__name(evsel), ++n);
> return NULL;
> }
>
> @@ -1779,12 +1778,10 @@ static struct syscall *trace__syscall_info(struct trace *trace,
> return &trace->syscalls.table[id];
>
> out_cant_read:
> - if (verbose > 0) {
> - fprintf(trace->output, "Problems reading syscall %d", id);
> - if (id <= trace->syscalls.max && trace->syscalls.table[id].name != NULL)
> - fprintf(trace->output, "(%s)", trace->syscalls.table[id].name);
> - fputs(" information\n", trace->output);
> - }
> + pr_debug("Problems reading syscall %d", id);
> + if (id <= trace->syscalls.max && trace->syscalls.table[id].name != NULL)
> + pr_debug("(%s)", trace->syscalls.table[id].name);
> + pr_debug(" information\n");
> return NULL;
> }
>
> --
> 2.17.1

--

- Arnaldo

2019-06-18 06:54:57

by Leo Yan

Subject: Re: [PATCH 1/2] perf trace: Use pr_debug() instead of fprintf() for logging

On Mon, Jun 17, 2019 at 12:24:12PM -0300, Arnaldo Carvalho de Melo wrote:
> Em Mon, Jun 17, 2019 at 05:11:39PM +0800, Leo Yan escreveu:
> > In the function trace__syscall_info(), it explicitly checks verbose
> > level and print out log with fprintf(). Actually, we can use
> > pr_debug() to do the same thing for debug logging.
> >
> > This patch uses pr_debug() instead of fprintf() for debug logging; it
> > includes a minor fixing for 'space before tab in indent', which
> > dismisses git warning when apply it.
>
> But those are not fprintf(stdout,), they explicitely redirect to the
> output file that the user may have specified using 'perf trace --output
> filename.trace' :-)

Thanks for pointing out, sorry for noise. Please drop this patch.

Thanks,
Leo Yan

> > Signed-off-by: Leo Yan <[email protected]>
> > ---
> > tools/perf/builtin-trace.c | 21 +++++++++------------
> > 1 file changed, 9 insertions(+), 12 deletions(-)
> >
> > diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
> > index bd1f00e7a2eb..5cd74651db4c 100644
> > --- a/tools/perf/builtin-trace.c
> > +++ b/tools/perf/builtin-trace.c
> > @@ -1760,12 +1760,11 @@ static struct syscall *trace__syscall_info(struct trace *trace,
> > * grep "NR -1 " /t/trace_pipe
> > *
> > * After generating some load on the machine.
> > - */
> > - if (verbose > 1) {
> > - static u64 n;
> > - fprintf(trace->output, "Invalid syscall %d id, skipping (%s, %" PRIu64 ") ...\n",
> > - id, perf_evsel__name(evsel), ++n);
> > - }
> > + */
> > + static u64 n;
> > +
> > + pr_debug("Invalid syscall %d id, skipping (%s, %" PRIu64 ")\n",
> > + id, perf_evsel__name(evsel), ++n);
> > return NULL;
> > }
> >
> > @@ -1779,12 +1778,10 @@ static struct syscall *trace__syscall_info(struct trace *trace,
> > return &trace->syscalls.table[id];
> >
> > out_cant_read:
> > - if (verbose > 0) {
> > - fprintf(trace->output, "Problems reading syscall %d", id);
> > - if (id <= trace->syscalls.max && trace->syscalls.table[id].name != NULL)
> > - fprintf(trace->output, "(%s)", trace->syscalls.table[id].name);
> > - fputs(" information\n", trace->output);
> > - }
> > + pr_debug("Problems reading syscall %d", id);
> > + if (id <= trace->syscalls.max && trace->syscalls.table[id].name != NULL)
> > + pr_debug("(%s)", trace->syscalls.table[id].name);
> > + pr_debug(" information\n");
> > return NULL;
> > }
> >
> > --
> > 2.17.1
>
> --
>
> - Arnaldo