| Message ID | 20231005181448.176e9563@gandalf.local.home (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
| Series | libtraceeval: Add traceeval_stat_max/min_timestamp() API | expand |
On Thu, Oct 05, 2023 at 06:14:48PM -0400, Steven Rostedt wrote: > From: "Steven Rostedt (Google)" <rostedt@goodmis.org> > > If a value field is flagged as a TIMESTAMP, and another field is flagged > as a STAT, have the statistics for the STAT field automatically keep track > of when the max and min happened (what the TIMESTAMP field was at those > instances). I'm confused as to why we have TRACEEVAL_FL_TIMESTAMP and a separate data entry with that flag, instead of only storing the timestamp in the entry metadata, as we do with the other STATs? From the description above where we have one TIMESTAMP and one STAT, I would expect to see structures defined like this (from [PATCH v2] libtraceeval: Add wake-lat sample code): +struct traceeval_type sched_vals[] = { + { + .name = "timestamp", + .flags = TRACEEVAL_FL_TIMESTAMP, + .type = TRACEEVAL_TYPE_NUMBER_64, + }, + { + .name = "delta", + .flags = TRACEEVAL_FL_STAT, + .type = TRACEEVAL_TYPE_NUMBER_64, + } where the timestamp is sync'd with the STAT min and max, right? But we also have this: +struct traceeval_type wakeup_vals[] = { + { + .name = "timestamp", + .flags = TRACEEVAL_FL_TIMESTAMP, + .type = TRACEEVAL_TYPE_NUMBER_64, + } +}; in a structure that doesn't have a corresponding STAT field? This is also confusing to me because we need to keep 2 values (min and max TS), but this only holds one? The timestamp is already stored independently in the stat metadata in struct traceeval_stat: > struct traceeval_stat { > unsigned long long max; > + unsigned long long max_ts; > unsigned long long min; > + unsigned long long min_ts; > unsigned long long total; > unsigned long long std; > size_t count; which I think is enough? It seems like instead we really want our two flags to be: TRACEEVAL_FL_STAT and TRACEEVAL_FL_STAT_TS where the first just keeps the normal stats (min, max, average, std. dev, etc) and the second does all that plus timestamps for min and max? This would also allow you to keep min and max stats independently for multiple entries in a single structure, i.e.: struct traceeval_type task_vals[] = { { .name = "wake_delay", .flags = TRACEEVAL_FL_STAT_TS, .type = TRACEEVAL_TYPE_NUMBER_64, }, { .name = "runtime", .flags = TRACEEVAL_FL_STAT_TS, .type = TRACEEVAL_TYPE_NUMBER_64, } }; which I don't think is possible under the current scheme? What am I missing?
On Wed, 11 Oct 2023 16:21:00 -0600 Ross Zwisler <zwisler@google.com> wrote: > On Thu, Oct 05, 2023 at 06:14:48PM -0400, Steven Rostedt wrote: > > From: "Steven Rostedt (Google)" <rostedt@goodmis.org> > > > > If a value field is flagged as a TIMESTAMP, and another field is flagged > > as a STAT, have the statistics for the STAT field automatically keep track > > of when the max and min happened (what the TIMESTAMP field was at those > > instances). > > I'm confused as to why we have TRACEEVAL_FL_TIMESTAMP and a separate data > entry with that flag, instead of only storing the timestamp in the entry > metadata, as we do with the other STATs? Actually, I may remove this part entirely, as it's pretty much superseded by the TRACEEVAL_TYPE_DELTA, which I moved to, and haven't needed the separate val marked for the timestamp. > > >From the description above where we have one TIMESTAMP and one STAT, I would > expect to see structures defined like this > (from [PATCH v2] libtraceeval: Add wake-lat sample code): > > +struct traceeval_type sched_vals[] = { > + { > + .name = "timestamp", > + .flags = TRACEEVAL_FL_TIMESTAMP, > + .type = TRACEEVAL_TYPE_NUMBER_64, > + }, > + { > + .name = "delta", > + .flags = TRACEEVAL_FL_STAT, > + .type = TRACEEVAL_TYPE_NUMBER_64, > + } > > where the timestamp is sync'd with the STAT min and max, right? The new type is done like: { .name = "delta", .type = TRACEEVAL_TYPE_DELTA, } Which will automatically be marked as STAT flag, and is set with: TRACEEVAL_SET_DELTA(vals, delta, timestamp); Is that what you are thinking about? -- Steve > > But we also have this: > > +struct traceeval_type wakeup_vals[] = { > + { > + .name = "timestamp", > + .flags = TRACEEVAL_FL_TIMESTAMP, > + .type = TRACEEVAL_TYPE_NUMBER_64, > + } > +}; > > in a structure that doesn't have a corresponding STAT field? This is also > confusing to me because we need to keep 2 values (min and max TS), but this > only holds one? > > The timestamp is already stored independently in the stat metadata in > struct traceeval_stat: > > > struct traceeval_stat { > > unsigned long long max; > > + unsigned long long max_ts; > > unsigned long long min; > > + unsigned long long min_ts; > > unsigned long long total; > > unsigned long long std; > > size_t count; > > which I think is enough? > > It seems like instead we really want our two flags to be: > > TRACEEVAL_FL_STAT > and > TRACEEVAL_FL_STAT_TS > > where the first just keeps the normal stats (min, max, average, std. dev, etc) > and the second does all that plus timestamps for min and max? > > This would also allow you to keep min and max stats independently for multiple > entries in a single structure, i.e.: > > struct traceeval_type task_vals[] = { > { > .name = "wake_delay", > .flags = TRACEEVAL_FL_STAT_TS, > .type = TRACEEVAL_TYPE_NUMBER_64, > }, > { > .name = "runtime", > .flags = TRACEEVAL_FL_STAT_TS, > .type = TRACEEVAL_TYPE_NUMBER_64, > } > }; > > which I don't think is possible under the current scheme? > > What am I missing?
On Wed, Oct 11, 2023 at 07:09:17PM -0400, Steven Rostedt wrote: > On Wed, 11 Oct 2023 16:21:00 -0600 > Ross Zwisler <zwisler@google.com> wrote: > > > On Thu, Oct 05, 2023 at 06:14:48PM -0400, Steven Rostedt wrote: > > > From: "Steven Rostedt (Google)" <rostedt@goodmis.org> > > > > > > If a value field is flagged as a TIMESTAMP, and another field is flagged > > > as a STAT, have the statistics for the STAT field automatically keep track > > > of when the max and min happened (what the TIMESTAMP field was at those > > > instances). > > > > I'm confused as to why we have TRACEEVAL_FL_TIMESTAMP and a separate data > > entry with that flag, instead of only storing the timestamp in the entry > > metadata, as we do with the other STATs? > > Actually, I may remove this part entirely, as it's pretty much superseded > by the TRACEEVAL_TYPE_DELTA, which I moved to, and haven't needed the > separate val marked for the timestamp. > > > > > >From the description above where we have one TIMESTAMP and one STAT, I would > > expect to see structures defined like this > > (from [PATCH v2] libtraceeval: Add wake-lat sample code): > > > > +struct traceeval_type sched_vals[] = { > > + { > > + .name = "timestamp", > > + .flags = TRACEEVAL_FL_TIMESTAMP, > > + .type = TRACEEVAL_TYPE_NUMBER_64, > > + }, > > + { > > + .name = "delta", > > + .flags = TRACEEVAL_FL_STAT, > > + .type = TRACEEVAL_TYPE_NUMBER_64, > > + } > > > > where the timestamp is sync'd with the STAT min and max, right? > > The new type is done like: > > { > .name = "delta", > .type = TRACEEVAL_TYPE_DELTA, > } > > Which will automatically be marked as STAT flag, and is set with: > > TRACEEVAL_SET_DELTA(vals, delta, timestamp); > > Is that what you are thinking about? Yep, I think so. I'll take a harder look at TRACEEVAL_TYPE_DELTA.
diff --git a/include/traceeval.h b/include/traceeval.h index a70a5b09057b..bbf8f6ac7dd1 100644 --- a/include/traceeval.h +++ b/include/traceeval.h @@ -242,6 +242,10 @@ unsigned long long traceeval_stat_max(struct traceeval_stat *stat); unsigned long long traceeval_stat_min(struct traceeval_stat *stat); unsigned long long traceeval_stat_total(struct traceeval_stat *stat); unsigned long long traceeval_stat_count(struct traceeval_stat *stat); +unsigned long long traceeval_stat_max_timestamp(struct traceeval_stat *stat, + unsigned long long *ts); +unsigned long long traceeval_stat_min_timestamp(struct traceeval_stat *stat, + unsigned long long *ts); struct traceeval_iterator *traceeval_iterator_get(struct traceeval *teval); void traceeval_iterator_put(struct traceeval_iterator *iter); diff --git a/src/eval-local.h b/src/eval-local.h index 01b1b838e8bf..fabb1a06e7df 100644 --- a/src/eval-local.h +++ b/src/eval-local.h @@ -47,7 +47,9 @@ struct hash_table { struct traceeval_stat { unsigned long long max; + unsigned long long max_ts; unsigned long long min; + unsigned long long min_ts; unsigned long long total; unsigned long long std; size_t count; @@ -72,6 +74,7 @@ struct traceeval { size_t nr_elements; size_t sizeof_type; size_t sizeof_data; + ssize_t timestamp_idx; }; struct traceeval_iterator { diff --git a/src/histograms.c b/src/histograms.c index 2be95e6a8d1f..0cf52225a03a 100644 --- a/src/histograms.c +++ b/src/histograms.c @@ -222,15 +222,32 @@ static int check_keys(struct traceeval_type *keys, int cnt) return 0; } -static int check_vals(struct traceeval_type *vals, int cnt) +static int check_vals(struct traceeval *teval, struct traceeval_type *vals, int cnt) { + bool ts_found = false; + for (int i = 0; i < cnt && vals[i].type != TRACEEVAL_TYPE_NONE; i++) { /* Define this as a value */ vals[i].flags |= TRACEEVAL_FL_VALUE; vals[i].flags &= ~TRACEEVAL_FL_KEY; + if (vals[i].flags & TRACEEVAL_FL_TIMESTAMP) { + /* Only one field may be marked as a timestamp */ + if (ts_found) + return -1; + /* The type must be numeric */ + if (vals[i].type > TRACEEVAL_TYPE_NUMBER) + return -1; + /* TIMESTAMPS can not be STATs themselves */ + if (vals[i].flags & TRACEEVAL_FL_STAT) + return -1; + ts_found = true; + teval->timestamp_idx = i; + } vals[i].index = i; } + if (!ts_found) + teval->timestamp_idx = -1; return 0; } @@ -298,7 +315,7 @@ struct traceeval *traceeval_init_data_size(struct traceeval_type *keys, goto fail_release; if (vals) { - ret = check_vals(vals, nr_vals); + ret = check_vals(teval, vals, nr_vals); if (ret < 0) goto fail_release; } @@ -535,7 +552,8 @@ static bool is_stat_type(struct traceeval_type *type) static int copy_traceeval_data(struct traceeval_type *type, struct traceeval_stat *stat, struct traceeval_data *dst, - const struct traceeval_data *src) + const struct traceeval_data *src, + unsigned long long ts) { unsigned long long val; @@ -599,21 +617,31 @@ static int copy_traceeval_data(struct traceeval_type *type, if (!stat->count++) { stat->max = val; stat->min = val; + stat->max_ts = ts; + stat->min_ts = ts; stat->total = val; return 0; } if (type->flags & TRACEEVAL_FL_SIGNED) { - if ((long long)stat->max < (long long)val) + if ((long long)stat->max < (long long)val) { stat->max = val; - if ((long long)stat->min > (long long)val) + stat->max_ts = ts; + } + if ((long long)stat->min > (long long)val) { stat->min = val; + stat->min_ts = ts; + } stat->total += (long long)val; } else { - if (stat->max < val) + if (stat->max < val) { + stat->max_ts = ts; stat->max = val; - if (stat->min > val) + } + if (stat->min > val) { stat->min = val; + stat->min_ts = ts; + } stat->total += val; } @@ -654,7 +682,8 @@ static void data_release_and_free(size_t size, struct traceeval_data **data, static int dup_traceeval_data_set(size_t size, struct traceeval_type *type, struct traceeval_stat *stats, const struct traceeval_data *orig, - struct traceeval_data **copy) + struct traceeval_data **copy, + unsigned long long ts) { size_t i; @@ -668,7 +697,7 @@ static int dup_traceeval_data_set(size_t size, struct traceeval_type *type, for (i = 0; i < size; i++) { if (copy_traceeval_data(type + i, stats ? stats + i : NULL, - (*copy) + i, orig + i)) + (*copy) + i, orig + i, ts)) goto fail; } @@ -754,6 +783,14 @@ static struct entry *create_hist_entry(struct traceeval *teval, return entry; } +static unsigned long long get_timestamp(struct traceeval *teval, + const struct traceeval_data *vals) +{ + if (teval->timestamp_idx < 0) + return 0; + return vals[teval->timestamp_idx].number_64; +} + /* * Create a new entry in @teval with respect to @keys and @vals. * @@ -765,6 +802,7 @@ static int create_entry(struct traceeval *teval, { struct traceeval_data *new_keys; struct traceeval_data *new_vals; + unsigned long long ts; struct entry *entry; entry = create_hist_entry(teval, keys); @@ -775,14 +813,16 @@ static int create_entry(struct traceeval *teval, if (!entry->val_stats) goto fail_entry; + ts = get_timestamp(teval, vals); + /* copy keys */ if (dup_traceeval_data_set(teval->nr_key_types, teval->key_types, - NULL, keys, &new_keys) == -1) + NULL, keys, &new_keys, 0) == -1) goto fail_stats; /* copy vals */ if (dup_traceeval_data_set(teval->nr_val_types, teval->val_types, - entry->val_stats, vals, &new_vals) == -1) + entry->val_stats, vals, &new_vals, ts) == -1) goto fail; entry->keys = new_keys; @@ -818,12 +858,15 @@ static int update_entry(struct traceeval *teval, struct entry *entry, struct traceeval_type *types = teval->val_types; struct traceeval_data *copy = entry->vals; struct traceeval_data old[teval->nr_val_types]; + unsigned long long ts; size_t size = teval->nr_val_types; ssize_t i; if (!size) return 0; + ts = get_timestamp(teval, vals); + for (i = 0; i < teval->nr_val_types; i++) { if (vals[i].type != teval->val_types[i].type) return -1; @@ -833,7 +876,7 @@ static int update_entry(struct traceeval *teval, struct entry *entry, old[i] = copy[i]; if (copy_traceeval_data(types + i, stats + i, - copy + i, vals + i)) + copy + i, vals + i, ts)) goto fail; } data_release(size, old, types); @@ -844,7 +887,7 @@ static int update_entry(struct traceeval *teval, struct entry *entry, /* Put back the old values */ for (i--; i >= 0; i--) { copy_traceeval_data(types + i, NULL, - copy + i, old + i); + copy + i, old + i, 0); } return -1; } @@ -889,6 +932,38 @@ struct traceeval_stat *traceeval_stat_size(struct traceeval *teval, return &entry->val_stats[type->index]; } +/** + * traceeval_stat_max_timestamp - return max value of stat and where it happend + * @stat: The stat structure that holds the stats + * @ts: The return value for the time stamp of where the max happened + * + * Returns the max value within @stat, and the timestamp of where that max + * happened in @ts. + */ +unsigned long long traceeval_stat_max_timestamp(struct traceeval_stat *stat, + unsigned long long *ts) +{ + if (ts) + *ts = stat->max_ts; + return stat->max; +} + +/** + * traceeval_stat_min_timestamp - return min value of stat and where it happend + * @stat: The stat structure that holds the stats + * @ts: The return value for the time stamp of where the min happened + * + * Returns the min value within @stat, and the timestamp of where that min + * happened in @ts. + */ +unsigned long long traceeval_stat_min_timestamp(struct traceeval_stat *stat, + unsigned long long *ts) +{ + if (ts) + *ts = stat->min_ts; + return stat->min; +} + /** * traceeval_stat_max - return max value of stat * @stat: The stat structure that holds the stats @@ -897,7 +972,7 @@ struct traceeval_stat *traceeval_stat_size(struct traceeval *teval, */ unsigned long long traceeval_stat_max(struct traceeval_stat *stat) { - return stat->max; + return traceeval_stat_max_timestamp(stat, NULL); } /** @@ -908,7 +983,7 @@ unsigned long long traceeval_stat_max(struct traceeval_stat *stat) */ unsigned long long traceeval_stat_min(struct traceeval_stat *stat) { - return stat->min; + return traceeval_stat_min_timestamp(stat, NULL); } /**