From patchwork Fri Oct 6 18:54:05 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Steven Rostedt X-Patchwork-Id: 13411900 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7FE9128DCF for ; Fri, 6 Oct 2023 18:52:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=none Received: by smtp.kernel.org (Postfix) with ESMTPSA id 245CBC433CB; Fri, 6 Oct 2023 18:52:54 +0000 (UTC) Received: from rostedt by gandalf with local (Exim 4.96) (envelope-from ) id 1qopxe-005moe-25; Fri, 06 Oct 2023 14:54:06 -0400 From: Steven Rostedt To: linux-trace-devel@vger.kernel.org Cc: Ross Zwisler , "Steven Rostedt (Google)" Subject: [PATCH 3/3] libtraceeval: Add man pages for libtraceeval_delta retrieving of deltas Date: Fri, 6 Oct 2023 14:54:05 -0400 Message-Id: <20231006185405.1379249-4-rostedt@goodmis.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20231006185405.1379249-1-rostedt@goodmis.org> References: <20231006185405.1379249-1-rostedt@goodmis.org> Precedence: bulk X-Mailing-List: linux-trace-devel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: "Steven Rostedt (Google)" Add man pages for: traceeval_delta_stat() traceeval_delta_stat_size() traceeval_delta_teval_get() traceeval_delta_teval_put() traceeval_iterator_delta_stat() Signed-off-by: Steven Rostedt (Google) --- Documentation/libtraceeval-delta-rest.txt | 309 ++++++++++++++++++++++ Documentation/libtraceeval.txt | 14 + 2 files changed, 323 insertions(+) create mode 100644 Documentation/libtraceeval-delta-rest.txt diff --git a/Documentation/libtraceeval-delta-rest.txt b/Documentation/libtraceeval-delta-rest.txt new file mode 100644 index 000000000000..5043a74a569a --- /dev/null +++ b/Documentation/libtraceeval-delta-rest.txt @@ -0,0 +1,309 @@ +libtraceeval(3) +=============== + +NAME +---- +traceeval_delta_stat, traceeval_delta_stat_size, traceeval_delta_teval_get, +traceeval_delta_teval_put, traceeval_iterator_delta_stat - Reading the libtraceeval_data elements + +SYNOPSIS +-------- +[verse] +-- +*#include * + +struct traceeval_stat pass:[*]*traceeval_delta_stat*(struct traceeval_delta pass:[*]_tdelta_, + const struct traceeval_data pass:[*]_keys_) +struct traceeval_stat pass:[*]*traceeval_delta_stat_size*(struct traceeval_delta pass:[*]_tdelta_, + const struct traceeval_data pass:[*]_keys_, + size_t _nr_keys_); + +struct traceeval pass:[*]*traceeval_delta_teval_get*(struct traceeval_delta pass:[*]_tdelta_); + +void *traceeval_delta_teval_put*(struct traceeval_delta pass:[*]_tdelta_, + struct traceeval pass:[*]_teval_); + +struct traceeval_stat pass:[*]*traceeval_iterator_delta_stat*(struct traceeval_iterator pass:[*]_iter_); +-- + +DESCRIPTION +----------- +The traceeval_delta is used to record the time deltas between events. These +functions help show that information that was recorded. + +The *traceeval_delta_stat()* function will return a traceeval_stat descriptor +(see *traceeval_stat*(3)) for the time delta that it recorded for the element +represented by _keys_. The delta is calculated from various calls to +*traceeval_delta_start*(3) and *traceeval_delta_stop*(3). Since the delta field +of a traceeval_delta is not visible from other routines (nor is it name), the +way to get the information for the delta is via the *traceeval_delta_stat()* +function. + +The *traceeval_delta_stat()* requires _keys_ to be a static array, if it is a +dynamic array, then *traceeval_delta_stat_size()* must be used instead. This function +provides a parameter, _nr_keys_, to specify how many elements _keys_ has. Note that +_keys_ must be the same size as the keys passed to *traceeval_delta_init*(3). + +The traceeval_delta does not provide any direct means to use an iterator, so +a handle to its internal traceeval can be used for this purpose with +*traceeval_delta_teval_get()*. This will return the internal traceeval handle for +the given _tdelta traceeval_delta descriptor. The returned traceeval should only +be used with iterators, as other functions that take a traceeval descriptor will +likely have undefined results if used. + +When finished with the traceeval handle retrieved from traceeval_delta_teval_get(), +it should be passed to *traceeval_delta_teval_put()* along with the _tdelta_ that +was used by *traceeval_delta_teval_get()* to retrieve the _teval_ element. + +Because the delta stored in traceeval_delta is hidden, when using an iterator on +a traceeval that came from *traceeval_delta_teval_get()*, the *traceeval_iterator_delta_stat()* +can be used to retrieve the traceeval_stat that represents the internal delta +of the traceeval_delta the traceeval the iterator is using came from. + +RETURN VALUE +------------ +The *traceeval_iterator_get()* returns a traceeval_iterator descriptor that will iterate +over the given _teval_ on success, and NULL on error. + +The *traceeval_iterator_sort()* and traceeval_iterator_sort_custom()* return 0 on success and -1 or error. + +The *traceeval_iterator_next()* returns 1 when it reads a new element from the traceeval and places the element's +keys into _keys_. It returns 0 when there's no more elements to read and -1 on error. + +The *traceeval_iterator_query()* returns 1 if it successfully reads the current element from the +*traceeval_iterator_next()* and places the values in _results_. It returns 0 if there are no more elements, +and -1 on error. + +The *traceeval_iterator_stat()* returns a descriptor for the current element's given _field_ on success and +NULL if there are no current elements or the _field_ is not a valid stat type. + +The *traceeval_iterator_remove()* returns 1 if the current element was successfully removed, or 0 +if there was no element (called before *traceeval_iterator_next()*). + +EXAMPLE +------- +[source,c] +-- +#include +#include + +static struct traceeval_type task_types[] = { + { + .name = "COMM", + .type = TRACEEVAL_TYPE_STRING, + }, + { + .name = "PID", + .type = TRACEEVAL_TYPE_NUMBER, + } +}; + +static struct traceeval_type cpu_types[] = { + { + .name = "CPU", + .type = TRACEEVAL_TYPE_NUMBER, + } +}; + +struct data { + struct traceeval_delta *tdelta_tasks; + struct traceeval_delta *tdelta_cpus; +}; + +static struct tep_format_field *get_field(struct tep_event *event, const char *name) +{ + static struct tep_format_field *field; + + field = tep_find_field(event, name); + if (!field) { + fprintf(stderr, "Could not find field %s for %s", name, event->name); + exit(-1); + } + + return field; +} + +static int switch_func(struct tracecmd_input *handle, struct tep_event *event, + struct tep_record *record, int cpu, void *d) +{ + static struct tep_format_field *prev_comm; + static struct tep_format_field *prev_pid; + static struct tep_format_field *next_comm; + static struct tep_format_field *next_pid; + struct traceeval_data task_keys[2]; + struct traceeval_data cpu_keys[1]; + struct data *data = d; + unsigned long long val; + const char *comm; + + if (!next_comm) { + prev_comm = get_field(event, "prev_comm"); + prev_pid = get_field(event, "prev_pid"); + + next_comm = get_field(event, "next_comm"); + next_pid = get_field(event, "next_pid"); + } + + comm = record->data + prev_comm->offset; + tep_read_number_field(prev_pid, record->data, &val); + + TRACEEVAL_SET_CSTRING(task_keys[0], comm); + TRACEEVAL_SET_NUMBER(task_keys[1], val); + + if (val) + traceeval_delta_stop(data->tdelta_tasks, task_keys, record->ts); + + comm = record->data + next_comm->offset; + tep_read_number_field(next_pid, record->data, &val); + + TRACEEVAL_SET_CSTRING(task_keys[0], comm); + TRACEEVAL_SET_NUMBER(task_keys[1], val); + + TRACEEVAL_SET_NUMBER(cpu_keys[0], record->cpu); + + if (val) { + if (traceeval_delta_start(data->tdelta_tasks, task_keys, record->ts) < 0) + printf("FAILED\n"); + traceeval_delta_continue(data->tdelta_cpus, cpu_keys, record->ts); + } else { + traceeval_delta_stop(data->tdelta_cpus, cpu_keys, record->ts); + } + + return 0; +} + +static void print_microseconds(int idx, unsigned long long nsecs) +{ + unsigned long long usecs; + + usecs = nsecs / 1000; + if (!nsecs || usecs) + printf("%*lld", idx, usecs); + else + printf("%*d.%03lld", idx, 0, nsecs); +} + +static void print_stat(struct traceeval_stat *stat) +{ + unsigned long long total; + unsigned long long cnt; + unsigned long long ts; + + printf("\tmax: "); + print_microseconds(12, traceeval_stat_max_timestamp(stat, &ts)); + printf(" timestamp: "); + print_microseconds(10, ts); + printf("\n\tmin: "); + print_microseconds(12, traceeval_stat_min_timestamp(stat, &ts)); + printf(" timestamp: "); + print_microseconds(10, ts); + printf("\n\ttotal: "); + total = traceeval_stat_total(stat); + print_microseconds(10, total); + cnt = traceeval_stat_count(stat); + printf("\n\tcount: %*lld\n", 10, cnt); + printf("\taverage:"); + print_microseconds(9, cnt ? total / cnt : 0); + printf("\n"); +} + +static void display_cpus(struct traceeval_delta *tdelta) +{ + struct traceeval *teval = traceeval_delta_teval_get(tdelta); + struct traceeval_iterator *iter = traceeval_iterator_get(teval); + const struct traceeval_data *keys; + + printf("\n"); + + traceeval_iterator_sort(iter, cpu_types[0].name, 0, true); + + while (traceeval_iterator_next(iter, &keys) > 0) { + struct traceeval_stat *stat; + + stat = traceeval_iterator_delta_stat(iter); + + printf("CPU [%zd]:\n", keys[0].number); + print_stat(stat); + } + traceeval_delta_teval_put(tdelta, teval); +} + +static void display_tasks(struct traceeval_delta *tdelta) +{ + struct traceeval *teval = traceeval_delta_teval_get(tdelta); + struct traceeval_iterator *iter = traceeval_iterator_get(teval); + const struct traceeval_data *keys; + + printf("\n"); + + traceeval_iterator_sort(iter, task_types[0].name, 0, true); + traceeval_iterator_sort(iter, task_types[1].name, 1, true); + + while (traceeval_iterator_next(iter, &keys) > 0) { + struct traceeval_stat *stat; + + stat = traceeval_iterator_delta_stat(iter); + + printf("Task %s [%zd]:\n", keys[0].cstring, keys[1].number); + print_stat(stat); + } + + traceeval_delta_teval_put(tdelta, teval); +}; + +int main (int argc, char **argv) +{ + struct tracecmd_input *handle; + struct data data; + + if (argc < 2) { + printf("Need to pass trace.dat file to this\n"); + exit(-1); + } + + handle = tracecmd_open(argv[1], TRACECMD_FL_LOAD_NO_PLUGINS); + + data.tdelta_tasks = traceeval_delta_init(task_types, NULL); + data.tdelta_cpus = traceeval_delta_init(cpu_types, NULL); + + tracecmd_follow_event(handle, "sched", "sched_switch", switch_func, &data); + tracecmd_iterate_events(handle, NULL, 0, NULL, NULL); + + display_cpus(data.tdelta_cpus); + display_tasks(data.tdelta_tasks); + + traceeval_delta_release(data.tdelta_cpus); + traceeval_delta_release(data.tdelta_tasks); + + return 0; +} +-- + +FILES +----- +[verse] +-- +*traceval.h* + Header file to include in order to have access to the library APIs. +*-ltraceeval* + Linker switch to add when building a program that uses the library. +-- + +SEE ALSO +-------- +*libtraceeval*(3) + +AUTHOR +------ +[verse] +-- +*Steven Rostedt* , author of *libtraceeval*. +-- +REPORTING BUGS +-------------- +Report bugs to + +LICENSE +------- +libtraceeval is licensed under MIT. + diff --git a/Documentation/libtraceeval.txt b/Documentation/libtraceeval.txt index 68fc182f7c46..f30d427255e1 100644 --- a/Documentation/libtraceeval.txt +++ b/Documentation/libtraceeval.txt @@ -125,6 +125,20 @@ Handling insertion, deletion and querying of traceeval_delta elements: void *traceeval_delta_results_release*(struct traceeval_delta pass:[*]_tdelta_, const struct traceeval_data pass:[*]_results_); + +Handling reading the deltas of a traceeval_delta: + struct traceeval_stat pass:[*]*traceeval_delta_stat*(struct traceeval_delta pass:[*]_tdelta_, + const struct traceeval_data pass:[*]_keys_) + struct traceeval_stat pass:[*]*traceeval_delta_stat_size*(struct traceeval_delta pass:[*]_tdelta_, + const struct traceeval_data pass:[*]_keys_, + size_t _nr_keys_); + + struct traceeval pass:[*]*traceeval_delta_teval_get*(struct traceeval_delta pass:[*]_tdelta_); + + void *traceeval_delta_teval_put*(struct traceeval_delta pass:[*]_tdelta_, + struct traceeval pass:[*]_teval_); + + struct traceeval_stat pass:[*]*traceeval_iterator_delta_stat*(struct traceeval_iterator pass:[*]_iter_); -- DESCRIPTION