From: "Tzvetomir Stoyanov (VMware)" <tz.stoyanov@gmail.com>
To: rostedt@goodmis.org
Cc: linux-trace-devel@vger.kernel.org
Subject: [PATCH v31 04/16] trace-cmd: Wait for first time sync before the trace
Date: Thu, 11 Mar 2021 10:48:45 +0200 [thread overview]
Message-ID: <20210311084857.1919805-5-tz.stoyanov@gmail.com> (raw)
In-Reply-To: <20210311084857.1919805-1-tz.stoyanov@gmail.com>
Added a barrier in time synchronization threads to ensure the first time
synchronization passed before to start the trace.
Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
---
lib/trace-cmd/trace-timesync.c | 15 ++++++++++++++-
1 file changed, 14 insertions(+), 1 deletion(-)
diff --git a/lib/trace-cmd/trace-timesync.c b/lib/trace-cmd/trace-timesync.c
index d38ee975..1e8ba509 100644
--- a/lib/trace-cmd/trace-timesync.c
+++ b/lib/trace-cmd/trace-timesync.c
@@ -571,6 +571,7 @@ void tracecmd_tsync_free(struct tracecmd_time_sync *tsync)
}
pthread_mutex_destroy(&tsync->lock);
pthread_cond_destroy(&tsync->cond);
+ pthread_barrier_destroy(&tsync->first_sync);
free(tsync->clock_str);
free(tsync->proto_name);
free(tsync);
@@ -753,6 +754,7 @@ static int tsync_with_guest(struct tracecmd_time_sync *tsync)
int ts_array_size = CLOCK_TS_ARRAY;
struct tsync_proto *proto;
struct timespec timeout;
+ bool first = true;
bool end = false;
int ret;
int i;
@@ -777,6 +779,10 @@ static int tsync_with_guest(struct tracecmd_time_sync *tsync)
if (ret)
break;
}
+ if (first) {
+ first = false;
+ pthread_barrier_wait(&tsync->first_sync);
+ }
if (end || i < tsync->vcpu_count)
break;
if (tsync->loop_interval > 0) {
@@ -804,12 +810,17 @@ static int tsync_with_guest(struct tracecmd_time_sync *tsync)
static void *tsync_host_thread(void *data)
{
struct tracecmd_time_sync *tsync = NULL;
+ int ret;
tsync = (struct tracecmd_time_sync *)data;
- tsync_with_guest(tsync);
+ ret = tsync_with_guest(tsync);
tracecmd_msg_handle_close(tsync->msg_handle);
tsync->msg_handle = NULL;
+ /* tsync with guest failed, release the barrier */
+ if (ret)
+ pthread_barrier_wait(&tsync->first_sync);
+
pthread_exit(0);
}
@@ -868,6 +879,7 @@ tracecmd_tsync_with_guest(unsigned long long trace_id, int loop_interval,
tsync->clock_str = strdup(clock);
pthread_mutex_init(&tsync->lock, NULL);
pthread_cond_init(&tsync->cond, NULL);
+ pthread_barrier_init(&tsync->first_sync, NULL, 2);
pthread_attr_init(&attrib);
pthread_attr_setdetachstate(&attrib, PTHREAD_CREATE_JOINABLE);
@@ -878,6 +890,7 @@ tracecmd_tsync_with_guest(unsigned long long trace_id, int loop_interval,
if (!get_first_cpu(&pin_mask, &mask_size))
pthread_setaffinity_np(tsync->thread, mask_size, pin_mask);
+ pthread_barrier_wait(&tsync->first_sync);
if (pin_mask)
CPU_FREE(pin_mask);
--
2.29.2
next prev parent reply other threads:[~2021-03-11 8:49 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-11 8:48 [PATCH v31 00/16] Timestamp synchronization of host - guest tracing session Tzvetomir Stoyanov (VMware)
2021-03-11 8:48 ` [PATCH v31 01/16] trace-cmd: Add timestamp synchronization per vCPU Tzvetomir Stoyanov (VMware)
2021-03-11 8:48 ` [PATCH v31 02/16] trace-cmd: Add dummy function to initialize timestamp sync logic Tzvetomir Stoyanov (VMware)
2021-03-11 8:48 ` [PATCH v31 03/16] trace-cmd: Move time sync logic in the trace-cmd library Tzvetomir Stoyanov (VMware)
2021-03-11 8:48 ` Tzvetomir Stoyanov (VMware) [this message]
2021-03-11 8:48 ` [PATCH v31 05/16] trace-cmd: PTP-like algorithm for host - guest timestamp synchronization Tzvetomir Stoyanov (VMware)
2021-03-11 8:48 ` [PATCH v31 06/16] trace-cmd: Debug scripts for " Tzvetomir Stoyanov (VMware)
2021-03-11 8:48 ` [PATCH v31 07/16] trace-cmd [POC]: Add KVM timestamp synchronization plugin Tzvetomir Stoyanov (VMware)
2021-03-11 8:48 ` [PATCH v31 08/16] trace-cmd: Add initial perf interface in trace-cmd library Tzvetomir Stoyanov (VMware)
2021-03-11 8:48 ` [PATCH v31 09/16] trace-cmd: Add logic for TSC to nanosecond conversion Tzvetomir Stoyanov (VMware)
2021-03-11 8:48 ` [PATCH v31 10/16] trace-cmd: Append new options into guest trace file at the end of the tracing session Tzvetomir Stoyanov (VMware)
2021-03-11 8:48 ` [PATCH v31 11/16] trace-cmd: Add a new option in trace file metadata for tsc2nsec conversion Tzvetomir Stoyanov (VMware)
2021-03-11 8:48 ` [PATCH v31 12/16] trace-cmd: Save information for tsc to nanoseconds conversion in trace file Tzvetomir Stoyanov (VMware)
2021-03-11 8:48 ` [PATCH v31 13/16] trace-cmd: Read information for tsc to nanoseconds conversion from " Tzvetomir Stoyanov (VMware)
2021-03-11 8:48 ` [PATCH v31 14/16] trace-cmd: Remove unneeded multiply in events timestamp reading Tzvetomir Stoyanov (VMware)
2021-03-11 8:48 ` [PATCH v31 15/16] trace-cmd: Perform all timestamp corrections in a single function Tzvetomir Stoyanov (VMware)
2021-03-11 8:48 ` [PATCH v31 16/16] trace-cmd: Convert tsc timestamps to nanosecods when reading trace data from a file Tzvetomir Stoyanov (VMware)
Reply instructions:
You may reply publicly 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=20210311084857.1919805-5-tz.stoyanov@gmail.com \
--to=tz.stoyanov@gmail.com \
--cc=linux-trace-devel@vger.kernel.org \
--cc=rostedt@goodmis.org \
/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
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).