bcachefs: bch2_time_stats_to_seq_buf()

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

2 files changed, 104 insertions, 0 deletions

diff --git a/fs/bcachefs/time_stats.c b/fs/bcachefs/time_stats.c
index 4508e9dcbee2..61047915c3d1 100644
--- a/fs/bcachefs/time_stats.c
+++ b/fs/bcachefs/time_stats.c
@@ -151,6 +151,107 @@ void __bch2_time_stats_update(struct bch2_time_stats *stats, u64 start, u64 end)
 	}
 }
 
+#include <linux/seq_buf.h>
+
+static void seq_buf_time_units_aligned(struct seq_buf *out, u64 ns)
+{
+	const struct time_unit *u = bch2_pick_time_units(ns);
+
+	seq_buf_printf(out, "%8llu %s", div64_u64(ns, u->nsecs), u->name);
+}
+
+void bch2_time_stats_to_seq_buf(struct seq_buf *out, struct bch2_time_stats *stats)
+{
+	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)
+			__bch2_time_stats_clear_buffer(stats, per_cpu_ptr(stats->buffer, cpu));
+		spin_unlock_irq(&stats->lock);
+	}
+
+	/*
+	 * avoid divide by zero
+	 */
+	if (stats->freq_stats.n) {
+		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);
+	}
+
+	seq_buf_printf(out, "count: %llu\n", stats->duration_stats.n);
+
+	seq_buf_printf(out, "                       since mount        recent\n");
+
+	seq_buf_printf(out, "duration of events\n");
+
+	seq_buf_printf(out, "  min:                     ");
+	seq_buf_time_units_aligned(out, stats->min_duration);
+	seq_buf_printf(out, "\n");
+
+	seq_buf_printf(out, "  max:                     ");
+	seq_buf_time_units_aligned(out, stats->max_duration);
+	seq_buf_printf(out, "\n");
+
+	seq_buf_printf(out, "  total:                   ");
+	seq_buf_time_units_aligned(out, stats->total_duration);
+	seq_buf_printf(out, "\n");
+
+	seq_buf_printf(out, "  mean:                    ");
+	seq_buf_time_units_aligned(out, d_mean);
+	seq_buf_time_units_aligned(out, mean_and_variance_weighted_get_mean(stats->duration_stats_weighted, TIME_STATS_MV_WEIGHT));
+	seq_buf_printf(out, "\n");
+
+	seq_buf_printf(out, "  stddev:                  ");
+	seq_buf_time_units_aligned(out, d_stddev);
+	seq_buf_time_units_aligned(out, mean_and_variance_weighted_get_stddev(stats->duration_stats_weighted, TIME_STATS_MV_WEIGHT));
+	seq_buf_printf(out, "\n");
+
+	seq_buf_printf(out, "time between events\n");
+
+	seq_buf_printf(out, "  min:                     ");
+	seq_buf_time_units_aligned(out, stats->min_freq);
+	seq_buf_printf(out, "\n");
+
+	seq_buf_printf(out, "  max:                     ");
+	seq_buf_time_units_aligned(out, stats->max_freq);
+	seq_buf_printf(out, "\n");
+
+	seq_buf_printf(out, "  mean:                    ");
+	seq_buf_time_units_aligned(out, f_mean);
+	seq_buf_time_units_aligned(out, mean_and_variance_weighted_get_mean(stats->freq_stats_weighted, TIME_STATS_MV_WEIGHT));
+	seq_buf_printf(out, "\n");
+
+	seq_buf_printf(out, "  stddev:                  ");
+	seq_buf_time_units_aligned(out, f_stddev);
+	seq_buf_time_units_aligned(out, mean_and_variance_weighted_get_stddev(stats->freq_stats_weighted, TIME_STATS_MV_WEIGHT));
+	seq_buf_printf(out, "\n");
+
+	if (quantiles) {
+		int i = eytzinger0_first(NR_QUANTILES);
+		const struct time_unit *u =
+			bch2_pick_time_units(quantiles->entries[i].m);
+		u64 last_q = 0;
+
+		seq_buf_printf(out, "quantiles (%s):\t", u->name);
+		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 ", div_u64(q, u->nsecs));
+			if (is_last)
+				seq_buf_printf(out, "\n");
+			last_q = q;
+		}
+	}
+}
+
 void bch2_time_stats_exit(struct bch2_time_stats *stats)
 {
 	free_percpu(stats->buffer);
diff --git a/fs/bcachefs/time_stats.h b/fs/bcachefs/time_stats.h
index 5df61403744b..3d543f5c3721 100644
--- a/fs/bcachefs/time_stats.h
+++ b/fs/bcachefs/time_stats.h
@@ -142,6 +142,9 @@ static inline bool track_event_change(struct bch2_time_stats *stats, bool v)
 	return false;
 }
 
+struct seq_buf;
+void bch2_time_stats_to_seq_buf(struct seq_buf *, struct bch2_time_stats *);
+
 void bch2_time_stats_exit(struct bch2_time_stats *);
 void bch2_time_stats_init(struct bch2_time_stats *);