From: Darrick J. Wong <[email protected]> Export json versions of time statistics information. Given the tabular nature of the numbers exposed, this will make it a lot easier for higher (than C) level languages (e.g. python) to import information without needing to write yet another clumsy string parser.
Signed-off-by: Darrick J. Wong <[email protected]> Signed-off-by: Kent Overstreet <[email protected]> --- include/linux/time_stats.h | 2 + lib/time_stats.c | 87 ++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 89 insertions(+) diff --git a/include/linux/time_stats.h b/include/linux/time_stats.h index b3c810fff963a..4e1f5485ed039 100644 --- a/include/linux/time_stats.h +++ b/include/linux/time_stats.h @@ -156,6 +156,8 @@ static inline bool track_event_change(struct time_stats *stats, bool v) struct seq_buf; void time_stats_to_seq_buf(struct seq_buf *, struct time_stats *, const char *epoch_name, unsigned int flags); +void time_stats_to_json(struct seq_buf *, struct time_stats *, + const char *epoch_name, unsigned int flags); void time_stats_exit(struct time_stats *); void time_stats_init(struct time_stats *); diff --git a/lib/time_stats.c b/lib/time_stats.c index 0fb3d854e503b..c0f209dd9f6dd 100644 --- a/lib/time_stats.c +++ b/lib/time_stats.c @@ -266,6 +266,93 @@ void time_stats_to_seq_buf(struct seq_buf *out, struct time_stats *stats, } EXPORT_SYMBOL_GPL(time_stats_to_seq_buf); +void time_stats_to_json(struct seq_buf *out, struct time_stats *stats, + const char *epoch_name, unsigned int flags) +{ + struct quantiles *quantiles = time_stats_to_quantiles(stats); + s64 f_mean = 0, d_mean = 0; + u64 f_stddev = 0, d_stddev = 0; + + if (stats->buffer) { + int cpu; + + spin_lock_irq(&stats->lock); + for_each_possible_cpu(cpu) + __time_stats_clear_buffer(stats, per_cpu_ptr(stats->buffer, cpu)); + spin_unlock_irq(&stats->lock); + } + + if (stats->freq_stats.n) { + /* avoid divide by zero */ + f_mean = mean_and_variance_get_mean(stats->freq_stats); + f_stddev = mean_and_variance_get_stddev(stats->freq_stats); + d_mean = mean_and_variance_get_mean(stats->duration_stats); + d_stddev = mean_and_variance_get_stddev(stats->duration_stats); + } else if (flags & TIME_STATS_PRINT_NO_ZEROES) { + /* unless we didn't want zeroes anyway */ + return; + } + + seq_buf_printf(out, "{\n"); + seq_buf_printf(out, " \"epoch\": \"%s\",\n", epoch_name); + seq_buf_printf(out, " \"count\": %llu,\n", stats->duration_stats.n); + + seq_buf_printf(out, " \"duration_ns\": {\n"); + seq_buf_printf(out, " \"min\": %llu,\n", stats->min_duration); + seq_buf_printf(out, " \"max\": %llu,\n", stats->max_duration); + seq_buf_printf(out, " \"total\": %llu,\n", stats->total_duration); + seq_buf_printf(out, " \"mean\": %llu,\n", d_mean); + seq_buf_printf(out, " \"stddev\": %llu\n", d_stddev); + seq_buf_printf(out, " },\n"); + + d_mean = mean_and_variance_weighted_get_mean(stats->duration_stats_weighted, TIME_STATS_MV_WEIGHT); + d_stddev = mean_and_variance_weighted_get_stddev(stats->duration_stats_weighted, TIME_STATS_MV_WEIGHT); + + seq_buf_printf(out, " \"duration_ewma_ns\": {\n"); + seq_buf_printf(out, " \"mean\": %llu,\n", d_mean); + seq_buf_printf(out, " \"stddev\": %llu\n", d_stddev); + seq_buf_printf(out, " },\n"); + + seq_buf_printf(out, " \"frequency_ns\": {\n"); + seq_buf_printf(out, " \"min\": %llu,\n", stats->min_freq); + seq_buf_printf(out, " \"max\": %llu,\n", stats->max_freq); + seq_buf_printf(out, " \"mean\": %llu,\n", f_mean); + seq_buf_printf(out, " \"stddev\": %llu\n", f_stddev); + seq_buf_printf(out, " },\n"); + + f_mean = mean_and_variance_weighted_get_mean(stats->freq_stats_weighted, TIME_STATS_MV_WEIGHT); + f_stddev = mean_and_variance_weighted_get_stddev(stats->freq_stats_weighted, TIME_STATS_MV_WEIGHT); + + seq_buf_printf(out, " \"frequency_ewma_ns\": {\n"); + seq_buf_printf(out, " \"mean\": %llu,\n", f_mean); + seq_buf_printf(out, " \"stddev\": %llu\n", f_stddev); + + if (quantiles) { + u64 last_q = 0; + + /* close frequency_ewma_ns but signal more items */ + seq_buf_printf(out, " },\n"); + + seq_buf_printf(out, " \"quantiles_ns\": [\n"); + eytzinger0_for_each(i, NR_QUANTILES) { + bool is_last = eytzinger0_next(i, NR_QUANTILES) == -1; + + u64 q = max(quantiles->entries[i].m, last_q); + seq_buf_printf(out, " %llu", q); + if (!is_last) + seq_buf_printf(out, ", "); + last_q = q; + } + seq_buf_printf(out, " ]\n"); + } else { + /* close frequency_ewma_ns without dumping further */ + seq_buf_printf(out, " }\n"); + } + + seq_buf_printf(out, "}\n"); +} +EXPORT_SYMBOL_GPL(time_stats_to_json); + void time_stats_exit(struct time_stats *stats) { free_percpu(stats->buffer);
