On Tue, 3 Dec 2019 12:35:18 +0200
"Tzvetomir Stoyanov (VMware)" <tz.stoyanov@xxxxxxxxx> wrote:
> When tracing host and guest machines, both should use the same
> tracing clock for event timestamps. If a clock is specified
> as host tracing argument, with option "-C clock_name", the same
> is injected as guest tracing argument. If the user wants to use
> different tracing clocks, it can specify it using "-C clock_name"
> as guest tracing argument. In that case, the one specified by
> the user has higher priority.
>
> Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@xxxxxxxxx>
> ---
> tracecmd/trace-record.c | 19 +++++++++++++++++--
> 1 file changed, 17 insertions(+), 2 deletions(-)
>
> diff --git a/tracecmd/trace-record.c b/tracecmd/trace-record.c
> index 49730d6..e7fb1bd 100644
> --- a/tracecmd/trace-record.c
> +++ b/tracecmd/trace-record.c
> @@ -5405,6 +5405,8 @@ static void parse_record_options(int argc,
> char *sav;
> int name_counter = 0;
> int neg_event = 0;
> + struct buffer_instance *instance;
> + bool guest_config = false;
Should have a different name, like "clock_set", as "guest_config"
doesn't let us know what this is about.
>
> init_common_record_context(ctx, curr_cmd);
>
> @@ -5562,6 +5564,7 @@ static void parse_record_options(int argc,
> break;
> case 'C':
> ctx->instance->ftrace->clock = optarg;
> + guest_config = true;
> break;
> case 'v':
> neg_event = 1;
> @@ -5779,14 +5782,26 @@ static void parse_record_options(int argc,
>
> /* If --date is specified, prepend it to all guest VM flags */
> if (ctx->date) {
> - struct buffer_instance *instance;
> -
> for_all_instances(instance) {
> if (is_guest(instance))
> add_argv(instance, "--date", true);
> }
> }
>
> + if (guest_config) {
> + /* If -C is specified, prepend clock to all guest VM flags */
> + for_all_instances(instance) {
> + if (top_instance.ftrace->clock) {
> + if (is_guest(instance)) {
We should only append this, if the guest didn't have a clock set
already. As the change log seems to say, if the user states a "-C
clock" for the guest, that should take precedence over the host clock
set. That is, a user may specifically state that they are using a
different clock. If we have frequency and offset set, it should still
work with different clocks.
-- Steve
> + add_argv(instance,
> + (char *)top_instance.ftrace->clock,
> + true);
> + add_argv(instance, "-C", true);
> + }
> + }
> + }
> + }
> +
> if (!ctx->filtered && ctx->instance->filter_mod)
> add_func(&ctx->instance->filter_funcs,
> ctx->instance->filter_mod, "*");
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