On Wed, 24 Mar 2021 15:04:17 +0200
"Tzvetomir Stoyanov (VMware)" <tz.stoyanov@xxxxxxxxx> wrote:
> Save the content of the trace_clock file in the TRACECLOCK option in
> the trace.dat file. The clocks can be printed with "trace-cmd dump
> --options" command.
> These clocks were saved right before the tracing data in the file, but
> this patch set changed that logic. Now only the selected clock is saved
> in the file before the tracing data.
> Having all supported trace clocks in the file is useful for debug
> purposes. Adding clocks in the existing TRACECLOCK option is save and
> will not break the older versions of trace-cmd.
>
> Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@xxxxxxxxx>
> ---
> tracecmd/trace-record.c | 6 +++++-
> 1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/tracecmd/trace-record.c b/tracecmd/trace-record.c
> index 2fc6723a..f4c27ef1 100644
> --- a/tracecmd/trace-record.c
> +++ b/tracecmd/trace-record.c
> @@ -4138,6 +4138,7 @@ enum {
> static void add_options(struct tracecmd_output *handle, struct common_record_context *ctx)
> {
> int type = 0;
> + char *clocks;
>
> if (ctx->date2ts) {
> if (ctx->data_flags & DATA_FL_DATE)
> @@ -4149,12 +4150,15 @@ static void add_options(struct tracecmd_output *handle, struct common_record_con
> if (type)
> tracecmd_add_option(handle, type, strlen(ctx->date2ts)+1, ctx->date2ts);
>
> - tracecmd_add_option(handle, TRACECMD_OPTION_TRACECLOCK, 0, NULL);
> + clocks = tracefs_instance_file_read(NULL, "trace_clock", NULL);
> + tracecmd_add_option(handle, TRACECMD_OPTION_TRACECLOCK,
> + clocks ? strlen(clocks)+1 : 0, clocks);
Strange. Even after applying this patch, I still get:
# ./tracecmd/trace-cmd dump
Tracing meta data in file trace.dat:
[Initial format]
6 [Version]
0 [Little endian]
8 [Bytes in a long]
4096 [Page size, bytes]
[Header page, 205 bytes]
[Header event, 205 bytes]
[Ftrace format, 15 events]
[Events format, 104 systems]
[Kallsyms, 6978379 bytes]
[Trace printk, 4997 bytes]
[Saved command lines, 1987 bytes]
8 [CPUs with tracing data]
[13 options]
[Flyrecord tracing data]
[Tracing clock]
No tracing clock saved in the file
Seems to be that it skips over the options unless you explicitly ask for it.
-- Steve
> add_option_hooks(handle);
> add_uname(handle);
> add_version(handle);
> if (!no_top_instance())
> add_trace_id(handle, &top_instance);
> + free(clocks);
> }
>
> static void write_guest_file(struct buffer_instance *instance)
|