From: "Yordan Karadzhov (VMware)" <y.karadz@gmail.com>
To: rostedt@goodmis.org
Cc: linux-trace-devel@vger.kernel.org,
"Yordan Karadzhov (VMware)" <y.karadz@gmail.com>
Subject: [PATCH v2 19/20] kernel-shark: Add methods for time calibration
Date: Mon, 12 Oct 2020 16:35:22 +0300 [thread overview]
Message-ID: <20201012133523.469040-20-y.karadz@gmail.com> (raw)
In-Reply-To: <20201012133523.469040-1-y.karadz@gmail.com>
We add an infrastructure for correcting the timestamps of the entries.
This is needed in order to correlate Data streams that have been
recorded using non-synchronized clocks. The infrastructure can handle
an arbitrary timestamps correction formula, however for the moment we
only provide calibration that adds a constant offset.
Signed-off-by: Yordan Karadzhov (VMware) <y.karadz@gmail.com>
---
src/libkshark-tepdata.c | 13 +++++-
src/libkshark.c | 99 +++++++++++++++++++++++++++++++++++++++++
src/libkshark.h | 27 +++++++++++
3 files changed, 138 insertions(+), 1 deletion(-)
diff --git a/src/libkshark-tepdata.c b/src/libkshark-tepdata.c
index d9d57843..31cb33d5 100644
--- a/src/libkshark-tepdata.c
+++ b/src/libkshark-tepdata.c
@@ -296,6 +296,9 @@ static ssize_t get_records(struct kshark_context *kshark_ctx,
entry = &temp_rec->entry;
missed_events_action(stream, rec, entry);
+ /* Apply time calibration. */
+ kshark_postprocess_entry(stream, rec, entry);
+
entry->stream_id = stream->stream_id;
temp_next = &temp_rec->next;
@@ -316,6 +319,12 @@ static ssize_t get_records(struct kshark_context *kshark_ctx,
entry->stream_id = stream->stream_id;
+ /*
+ * Post-process the content of the entry. This includes
+ * time calibration and event-specific plugin actions.
+ */
+ kshark_postprocess_entry(stream, rec, entry);
+
pid = entry->pid;
/* Apply Id filtering. */
@@ -481,8 +490,10 @@ static ssize_t tepdata_load_matrix(struct kshark_data_stream *stream,
if (cpu_array)
(*cpu_array)[count] = e->cpu;
- if (ts_array)
+ if (ts_array) {
+ kshark_calib_entry(stream, e);
(*ts_array)[count] = e->ts;
+ }
if (pid_array)
(*pid_array)[count] = e->pid;
diff --git a/src/libkshark.c b/src/libkshark.c
index 6f99dd6c..33476ed0 100644
--- a/src/libkshark.c
+++ b/src/libkshark.c
@@ -131,6 +131,7 @@ static void kshark_stream_free(struct kshark_data_stream *stream)
kshark_hash_id_free(stream->tasks);
+ free(stream->calib_array);
free(stream->file);
free(stream->name);
free(stream);
@@ -862,6 +863,37 @@ void kshark_plugin_actions(struct kshark_data_stream *stream,
}
}
+/**
+ * @brief Time calibration of the timestamp of the entry.
+ *
+ * @param stream: Input location for a Trace data stream pointer.
+ * @param entry: Output location for entry.
+ */
+void kshark_calib_entry(struct kshark_data_stream *stream,
+ struct kshark_entry *entry)
+{
+ if (stream->calib && stream->calib_array) {
+ /* Calibrate the timestamp of the entry. */
+ stream->calib(&entry->ts, stream->calib_array);
+ }
+}
+
+/**
+ * @brief Post-process the content of the entry. This includes time calibration
+ * and all registered event-specific plugin actions.
+ *
+ * @param stream: Input location for a Trace data stream pointer.
+ * @param record: Input location for the trace record.
+ * @param entry: Output location for entry.
+ */
+void kshark_postprocess_entry(struct kshark_data_stream *stream,
+ void *record, struct kshark_entry *entry)
+{
+ kshark_calib_entry(stream, entry);
+
+ kshark_plugin_actions(stream, record, entry);
+}
+
static inline void free_ptr(void *ptr)
{
if (ptr)
@@ -1259,6 +1291,73 @@ kshark_get_entry_back(const struct kshark_entry_request *req,
return get_entry(req, data, index, req->first, end, -1);
}
+static int compare_time(const void* a, const void* b)
+{
+ const struct kshark_entry *entry_a, *entry_b;
+
+ entry_a = *(const struct kshark_entry **) a;
+ entry_b = *(const struct kshark_entry **) b;
+
+ if (entry_a->ts > entry_b->ts)
+ return 1;
+
+ if (entry_a->ts < entry_b->ts)
+ return -1;
+
+ return 0;
+}
+
+static void kshark_data_qsort(struct kshark_entry **entries, size_t size)
+{
+ qsort(entries, size, sizeof(struct kshark_entry *), compare_time);
+}
+
+/**
+ * Add constant offset to the timestamp of the entry. To be used by the sream
+ * object as a System clock calibration callback function.
+ */
+void kshark_offset_calib(int64_t *ts, int64_t *argv)
+{
+ *ts += argv[0];
+}
+
+/**
+ * @brief Apply constant offset to the timestamps of all entries from a given
+ * Data stream.
+ *
+ * @param kshark_ctx: Input location for the session context pointer.
+ * @param entries: Input location for the trace data.
+ * @param size: The size of the trace data.
+ * @param sd: Data stream identifier.
+ * @param offset: The constant offset to be added (in nanosecond).
+ */
+void kshark_set_clock_offset(struct kshark_context *kshark_ctx,
+ struct kshark_entry **entries, size_t size,
+ int sd, int64_t offset)
+{
+ struct kshark_data_stream *stream;
+ int64_t correction;
+
+ stream = kshark_get_data_stream(kshark_ctx, sd);
+ if (!stream)
+ return;
+
+ if (!stream->calib_array) {
+ stream->calib = kshark_offset_calib;
+ stream->calib_array = calloc(1, sizeof(*stream->calib_array));
+ stream->calib_array_size = 1;
+ }
+
+ correction = offset - stream->calib_array[0];
+ stream->calib_array[0] = offset;
+
+ for (size_t i = 0; i < size; ++i)
+ if (entries[i]->stream_id == sd)
+ entries[i]->ts += correction;
+
+ kshark_data_qsort(entries, size);
+}
+
static int first_in_time_entry(struct kshark_entry_data_set *buffer, int n_buffers, size_t *count)
{
int64_t t_min = INT64_MAX;
diff --git a/src/libkshark.h b/src/libkshark.h
index fbe1b2ac..dc30665b 100644
--- a/src/libkshark.h
+++ b/src/libkshark.h
@@ -115,6 +115,12 @@ void kshark_hash_id_free(struct kshark_hash_id *hash);
int *kshark_hash_ids(struct kshark_hash_id *hash);
+/**
+ * Timestamp calibration function type. To be user for system clock
+ * calibration.
+ */
+typedef void (*time_calib_func) (int64_t *, int64_t *);
+
struct kshark_data_stream;
/** A function type to be used to initialize the interface of the data stream. */
@@ -315,6 +321,15 @@ struct kshark_data_stream {
/** The number of plugins registered for this stream.*/
int n_plugins;
+ /** System clock calibration function. */
+ time_calib_func calib;
+
+ /** An array of time calibration constants. */
+ int64_t *calib_array;
+
+ /** The size of the array of time calibration constants. */
+ size_t calib_array_size;
+
/** List of Plugin's Event handlers. */
struct kshark_event_proc_handler *event_handlers;
@@ -669,6 +684,12 @@ void kshark_clear_all_filters(struct kshark_context *kshark_ctx,
void kshark_plugin_actions(struct kshark_data_stream *stream,
void *record, struct kshark_entry *entry);
+void kshark_calib_entry(struct kshark_data_stream *stream,
+ struct kshark_entry *entry);
+
+void kshark_postprocess_entry(struct kshark_data_stream *stream,
+ void *record, struct kshark_entry *entry);
+
/** Search failed identifiers. */
enum kshark_search_failed {
/** All entries have greater timestamps. */
@@ -1059,6 +1080,12 @@ struct kshark_config_doc *kshark_open_config_file(const char *file_name,
struct kshark_config_doc *kshark_json_to_conf(struct json_object *jobj);
+void kshark_offset_calib(int64_t *ts, int64_t *atgv);
+
+void kshark_set_clock_offset(struct kshark_context *kshark_ctx,
+ struct kshark_entry **entries, size_t size,
+ int sd, int64_t offset);
+
/** Structure representing a data set made of KernelShark entries. */
struct kshark_entry_data_set {
/** Array of entries pointers. */
--
2.25.1
next prev parent reply other threads:[~2020-10-12 13:37 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-12 13:35 [PATCH v2 00/20] Start KernelShark v2 transformation Yordan Karadzhov (VMware)
2020-10-12 13:35 ` [PATCH v2 01/20] kernel-shark: Start introducing KernelShark 2.0 Yordan Karadzhov (VMware)
2020-10-12 13:35 ` [PATCH v2 02/20] kernel-shark: Use only signed types in kshark_entry Yordan Karadzhov (VMware)
2020-10-12 13:35 ` [PATCH v2 03/20] kernel-shark: Introduce libkshark-hash Yordan Karadzhov (VMware)
2020-10-12 14:05 ` Steven Rostedt
2020-10-12 14:05 ` Steven Rostedt
2020-10-12 14:18 ` Yordan Karadzhov (VMware)
2020-10-12 13:35 ` [PATCH v2 04/20] kernel-shark: Introduce Data streams Yordan Karadzhov (VMware)
2020-10-12 13:35 ` [PATCH v2 05/20] kernel-shark: Add stream_id to kshark_entry Yordan Karadzhov (VMware)
2020-10-13 0:05 ` Steven Rostedt
2020-10-29 10:08 ` Yordan Karadzhov (VMware)
2020-10-12 13:35 ` [PATCH v2 06/20] kernel-shark: Rename static methods in libkshark Yordan Karadzhov (VMware)
2020-10-12 13:35 ` [PATCH v2 07/20] kernel-shark: Add basic methods for Data streams Yordan Karadzhov (VMware)
2020-10-13 0:18 ` Steven Rostedt
2020-10-29 10:10 ` Yordan Karadzhov (VMware)
2020-10-29 14:04 ` Steven Rostedt
2020-10-29 14:49 ` Yordan Karadzhov (VMware)
2020-10-30 1:57 ` Steven Rostedt
2020-11-03 13:38 ` Yordan Karadzhov (VMware)
2020-11-04 15:41 ` Steven Rostedt
2020-11-05 14:35 ` Yordan Karadzhov (VMware)
2020-10-12 13:35 ` [PATCH v2 08/20] kernel-shark: Housekeeping before implementing stream interface Yordan Karadzhov (VMware)
2020-10-12 13:35 ` [PATCH v2 09/20] kernel-shark: Add stream interface for trace-cmd data Yordan Karadzhov (VMware)
2020-10-13 0:44 ` Steven Rostedt
2020-10-29 11:16 ` Yordan Karadzhov (VMware)
2020-10-12 13:35 ` [PATCH v2 10/20] kernel-shark: Start using data streams Yordan Karadzhov (VMware)
2020-10-14 18:56 ` Steven Rostedt
2020-11-05 14:58 ` Yordan Karadzhov (VMware)
2020-11-05 18:17 ` Steven Rostedt
2020-11-06 14:31 ` Yordan Karadzhov (VMware)
2020-11-06 15:18 ` Steven Rostedt
2020-11-09 14:49 ` Yordan Karadzhov (VMware)
2020-10-12 13:35 ` [PATCH v2 11/20] kernel-shark: Remove dead code Yordan Karadzhov (VMware)
2020-10-12 13:35 ` [PATCH v2 12/20] kernel-shark: Redesign the plugin interface Yordan Karadzhov (VMware)
2020-10-14 21:09 ` Steven Rostedt
2020-10-12 13:35 ` [PATCH v2 13/20] kernel-shark: Complete the stream integration Yordan Karadzhov (VMware)
2020-10-14 23:52 ` Steven Rostedt
2020-10-12 13:35 ` [PATCH v2 14/20] kernel-shark: Provide merging of multiple data streams Yordan Karadzhov (VMware)
2020-10-12 13:35 ` [PATCH v2 15/20] kernel-shark: Integrate the stream definitions with data model Yordan Karadzhov (VMware)
2020-10-12 13:35 ` [PATCH v2 16/20] kernel-shark: Use only signed types for model defs Yordan Karadzhov (VMware)
2020-10-12 13:35 ` [PATCH v2 17/20] kernel-shark: Add ksmodel_get_bin() Yordan Karadzhov (VMware)
2020-10-12 13:35 ` [PATCH v2 18/20] kernel-shark: Protect ksmodel_set_in_range_bining() Yordan Karadzhov (VMware)
2020-10-12 13:35 ` Yordan Karadzhov (VMware) [this message]
2020-10-12 13:35 ` [PATCH v2 20/20] kernel-shark: Integrate streams with libkshark-configio Yordan Karadzhov (VMware)
2020-11-05 19:22 ` Steven Rostedt
2020-11-09 14:55 ` Yordan Karadzhov (VMware)
2020-11-09 15:28 ` Steven Rostedt
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=20201012133523.469040-20-y.karadz@gmail.com \
--to=y.karadz@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).