Linux-Trace-Devel Archive on lore.kernel.org
 help / color / Atom feed
From: Steven Rostedt <rostedt@goodmis.org>
To: "Tzvetomir Stoyanov (VMware)" <tz.stoyanov@gmail.com>
Cc: linux-trace-devel@vger.kernel.org
Subject: Re: [PATCH v17 14/18] trace-cmd: Add host trace clock as guest trace argument
Date: Mon, 9 Dec 2019 14:31:01 -0500
Message-ID: <20191209143101.146cb619@gandalf.local.home> (raw)
In-Reply-To: <20191203103522.482684-15-tz.stoyanov@gmail.com>

On Tue,  3 Dec 2019 12:35:18 +0200
"Tzvetomir Stoyanov (VMware)" <tz.stoyanov@gmail.com> 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@gmail.com>
> ---
>  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, "*");


  reply index

Thread overview: 42+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-12-03 10:35 [PATCH v17 00/18]Timestamp synchronization of host - guest tracing session Tzvetomir Stoyanov (VMware)
2019-12-03 10:35 ` [PATCH v17 01/18] trace-cmd: Implement new lib API: tracecmd_local_events_system() Tzvetomir Stoyanov (VMware)
2019-12-03 10:35 ` [PATCH v17 02/18] trace-cmd: Add support for negative time offsets in trace.dat file Tzvetomir Stoyanov (VMware)
2019-12-03 10:35 ` [PATCH v17 03/18] trace-cmd: Add implementations of htonll() and ntohll() Tzvetomir Stoyanov (VMware)
2019-12-20 13:50   ` Steven Rostedt
2020-01-06 14:30     ` Tzvetomir Stoyanov
2019-12-03 10:35 ` [PATCH v17 04/18] trace-cmd: Add new library APIs for ftrace instances Tzvetomir Stoyanov (VMware)
2019-12-04 16:17   ` Steven Rostedt
2019-12-05 14:40     ` Tzvetomir Stoyanov
2019-12-03 10:35 ` [PATCH v17 05/18] trace-cmd: Add new library API for local CPU count Tzvetomir Stoyanov (VMware)
2019-12-04 20:09   ` Steven Rostedt
2019-12-03 10:35 ` [PATCH v17 06/18] trace-cmd: Add new library API for reading ftrace buffers Tzvetomir Stoyanov (VMware)
2019-12-04 21:10   ` Steven Rostedt
2019-12-03 10:35 ` [PATCH v17 07/18] trace-cmd: Find and store pids of tasks, which run virtual CPUs of given VM Tzvetomir Stoyanov (VMware)
2019-12-04 21:35   ` Steven Rostedt
2019-12-03 10:35 ` [PATCH v17 08/18] trace-cmd: Implement new API tracecmd_add_option_v() Tzvetomir Stoyanov (VMware)
2019-12-04 21:47   ` Steven Rostedt
2019-12-03 10:35 ` [PATCH v17 09/18] trace-cmd: Add new API to generate a unique ID of the tracing session Tzvetomir Stoyanov (VMware)
2019-12-03 10:35 ` [PATCH v17 10/18] trace-cmd: Store the session tracing ID in the trace.dat file Tzvetomir Stoyanov (VMware)
2019-12-03 10:35 ` [PATCH v17 11/18] trace-cmd: Exchange tracing IDs between host and guest Tzvetomir Stoyanov (VMware)
2019-12-04 22:03   ` Steven Rostedt
2019-12-03 10:35 ` [PATCH v17 12/18] trace-cmd: Implement new option in trace.dat file: TRACECMD_OPTION_TIME_SHIFT Tzvetomir Stoyanov (VMware)
2019-12-05  0:46   ` Steven Rostedt
2019-12-05 15:09     ` Tzvetomir Stoyanov
2019-12-03 10:35 ` [PATCH v17 13/18] trace-cmd: Add guest information in host's trace.dat file Tzvetomir Stoyanov (VMware)
2019-12-05  0:59   ` Steven Rostedt
2019-12-03 10:35 ` [PATCH v17 14/18] trace-cmd: Add host trace clock as guest trace argument Tzvetomir Stoyanov (VMware)
2019-12-09 19:31   ` Steven Rostedt [this message]
2019-12-10  8:49     ` Tzvetomir Stoyanov
2019-12-10 15:48       ` Steven Rostedt
2019-12-11  8:21         ` Tzvetomir Stoyanov
2019-12-11 15:01           ` Steven Rostedt
2019-12-03 10:35 ` [PATCH v17 15/18] trace-cmd: Refactor few trace-cmd internal functions Tzvetomir Stoyanov (VMware)
2019-12-09 19:32   ` Steven Rostedt
2019-12-03 10:35 ` [PATCH v17 16/18] trace-cmd: Basic infrastructure for host - guest timestamp synchronization Tzvetomir Stoyanov (VMware)
2019-12-10 17:04   ` Steven Rostedt
2019-12-10 18:39   ` Steven Rostedt
2019-12-12 12:34     ` Tzvetomir Stoyanov
2019-12-12 14:54       ` Steven Rostedt
2019-12-12 14:00     ` Tzvetomir Stoyanov
2019-12-03 10:35 ` [PATCH v17 17/18] trace-cmd: [POC] PTP-like algorithm " Tzvetomir Stoyanov (VMware)
2019-12-03 10:35 ` [PATCH v17 18/18] trace-cmd: Debug scripts for " Tzvetomir Stoyanov (VMware)

Reply instructions:

You may reply publically to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20191209143101.146cb619@gandalf.local.home \
    --to=rostedt@goodmis.org \
    --cc=linux-trace-devel@vger.kernel.org \
    --cc=tz.stoyanov@gmail.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux-Trace-Devel Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-trace-devel/0 linux-trace-devel/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-trace-devel linux-trace-devel/ https://lore.kernel.org/linux-trace-devel \
		linux-trace-devel@vger.kernel.org
	public-inbox-index linux-trace-devel

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-trace-devel


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git