Re: [PATCH V10 01/13] perf tools: add debug prints

From: Namhyung Kim
Date: Mon Aug 12 2013 - 22:54:34 EST


On Fri, 9 Aug 2013 13:51:47 +0300, Adrian Hunter wrote:
> It is useful to see the arguments to perf_event_open
> and whether the perf events ring buffer was mmapped
> per-cpu or per-thread. That information will now be
> displayed when verbose is 2 i.e option -vv

I have two nitpicks below, but other than that it looks good, so

Acked-by: Namhyung Kim <namhyung@xxxxxxxxxx>


[SNIP]

> +#define __PRINT_ATTR(fmt, cast, field) \
> + fprintf(fp, " %-19s "fmt"\n", #field, cast attr->field)
> +
> +#define PRINT_ATTR_U32(field) __PRINT_ATTR("%u" , , field)
> +#define PRINT_ATTR_X32(field) __PRINT_ATTR("%#x", , field)
> +#define PRINT_ATTR_U64(field) __PRINT_ATTR("%" PRIu64, (uint64_t), field)
> +#define PRINT_ATTR_X64(field) __PRINT_ATTR("%#"PRIx64, (uint64_t), field)
> +
> +#define PRINT_ATTR2N(name1, field1, name2, field2) \
> + fprintf(fp, " %-19s %u %-19s %u\n", \
> + name1, attr->field1, name2, attr->field2)
> +
> +#define PRINT_ATTR2(field1, field2) \
> + PRINT_ATTR2N(#field1, field1, #field2, field2)
> +
> +static size_t perf_event_attr__fprintf(struct perf_event_attr *attr, FILE *fp)
> +{
> + size_t ret = 0;
> +
> + ret += fprintf(fp, "------------------------------");
> + ret += fprintf(fp, "------------------------------\n");

We have 'graph_dotted_line' for this.


> + ret += fprintf(fp, "perf_event_attr:\n");
> +
> + ret += PRINT_ATTR_U32(type);
> + ret += PRINT_ATTR_U32(size);
> + ret += PRINT_ATTR_X64(config);
> + ret += PRINT_ATTR_U64(sample_period);
> + ret += PRINT_ATTR_U64(sample_freq);
> + ret += PRINT_ATTR_X64(sample_type);
> + ret += PRINT_ATTR_X64(read_format);
> +
> + ret += PRINT_ATTR2(disabled, inherit);
> + ret += PRINT_ATTR2(pinned, exclusive);
> + ret += PRINT_ATTR2(exclude_user, exclude_kernel);
> + ret += PRINT_ATTR2(exclude_hv, exclude_idle);
> + ret += PRINT_ATTR2(mmap, comm);
> + ret += PRINT_ATTR2(freq, inherit_stat);
> + ret += PRINT_ATTR2(enable_on_exec, task);
> + ret += PRINT_ATTR2(watermark, precise_ip);
> + ret += PRINT_ATTR2(mmap_data, sample_id_all);
> + ret += PRINT_ATTR2(exclude_host, exclude_guest);
> + ret += PRINT_ATTR2N("excl.callchain_kern", exclude_callchain_kernel,
> + "excl.callchain_user", exclude_callchain_user);
> +
> + ret += PRINT_ATTR_U32(wakeup_events);
> + ret += PRINT_ATTR_U32(wakeup_watermark);
> + ret += PRINT_ATTR_X32(bp_type);
> + ret += PRINT_ATTR_X64(bp_addr);
> + ret += PRINT_ATTR_X64(config1);
> + ret += PRINT_ATTR_U64(bp_len);
> + ret += PRINT_ATTR_X64(config2);
> + ret += PRINT_ATTR_X64(branch_sample_type);
> + ret += PRINT_ATTR_X64(sample_regs_user);
> + ret += PRINT_ATTR_U32(sample_stack_user);
> +
> + ret += fprintf(fp, "------------------------------");
> + ret += fprintf(fp, "------------------------------\n");
> +
> + return ret;
> +}

[SNIP]

> diff --git a/tools/perf/util/python.c b/tools/perf/util/python.c
> index 925e0c3..381f4fd 100644
> --- a/tools/perf/util/python.c
> +++ b/tools/perf/util/python.c
> @@ -8,6 +8,26 @@
> #include "cpumap.h"
> #include "thread_map.h"
>
> +/*
> + * Support debug printing even though util/debug.c is not linked. That means
> + * implementing 'verbose' and 'eprintf'.
> + */
> +int verbose;
> +
> +int eprintf(int level, const char *fmt, ...)
> +{
> + va_list args;
> + int ret = 0;
> +
> + if (verbose >= level) {
> + va_start(args, fmt);
> + ret = vfprintf(stderr, fmt, args);
> + va_end(args);
> + }
> +
> + return ret;
> +}

Not sure this duplication is the right way. Maybe linking util/debug.c
into the python extension and move trace_event() somewhere is a better
approach. But it'd make the util/debug.c more fragile?

Anyway this change could be splitted as a preparation patch.

Thanks,
Namhyung
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