Em Sat, Jun 27, 2020 at 09:36:44PM +0800, Changbin Du escreveu:
> We will reuse this function later.
>
> Signed-off-by: Changbin Du <changbin...@gmail.com>
> ---
> tools/perf/builtin-ftrace.c | 17 ++++++++++++-----
> 1 file changed, 12 insertions(+), 5 deletions(-)
>
> diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c
> index dceae70c3a22..003efa756322 100644
> --- a/tools/perf/builtin-ftrace.c
> +++ b/tools/perf/builtin-ftrace.c
> @@ -166,6 +166,17 @@ static int read_tracing_file_to_stdout(const char *name)
> return ret;
> }
>
> +static int write_tracing_file_int(const char *name, int value)
> +{
> + char buf[16];
> +
> + snprintf(buf, sizeof(buf), "%d", value);
> + if (write_tracing_file(name, buf) < 0)
> + return -1;
> +
> + return 0;
> +}
> +
> static int reset_tracing_cpu(void);
> static void reset_tracing_filters(void);
>
> @@ -296,8 +307,6 @@ static void reset_tracing_filters(void)
>
> static int set_tracing_depth(struct perf_ftrace *ftrace)
> {
> - char buf[16];
> -
> if (ftrace->graph_depth == 0)
> return 0;
>
> @@ -306,9 +315,7 @@ static int set_tracing_depth(struct perf_ftrace *ftrace)
> return -1;
> }
>
> - snprintf(buf, sizeof(buf), "%d", ftrace->graph_depth);
> -
> - if (write_tracing_file("max_graph_depth", buf) < 0)
> + if (write_tracing_file_int("max_graph_depth", ftrace->graph_depth) < 0)
> return -1;
We've been consolidating these sysfs, tracefs, debugfs, hugetlbfs, etc
in tools/lib/fs/, where we have things like:
[acme@quaco perf]$ grep "int sysfs__" tools/lib/api/fs/fs.c
static int sysfs__read_ull_base(const char *entry,
int sysfs__read_xll(const char *entry, unsigned long long *value)
int sysfs__read_ull(const char *entry, unsigned long long *value)
int sysfs__read_int(const char *entry, int *value)
int sysfs__read_str(const char *entry, char **buf, size_t *sizep)
int sysfs__read_bool(const char *entry, bool *value)
int sysfs__write_int(const char *entry, int value)
[acme@quaco perf]$ grep "int debugfs__" tools/lib/api/fs/fs.c
[acme@quaco perf]$ grep "int sysctl__" tools/lib/api/fs/fs.c
int sysctl__read_int(const char *sysctl, int *value)
[acme@quaco perf]$
Please take a look at tools/lib/api/fs/fs.h it already has the functions
to find the mount points, etc, so adding those there since you're
touchign this area now seems best.
- Arnaldo
