Add cutoff threshold for recovery auto-tuning

src/osd.cpp

@@ -233,6 +233,8 @@ void osd_t::parse_config(bool init)
         ? 10 : config["recovery_tune_agg_interval"].uint64_value();
     recovery_tune_sleep_min_us = config["recovery_tune_sleep_min_us"].is_null()
         ? 10 : config["recovery_tune_sleep_min_us"].uint64_value();
+    recovery_tune_sleep_cutoff_us = config["recovery_tune_sleep_cutoff_us"].is_null()
+        ? 10000000 : config["recovery_tune_sleep_cutoff_us"].uint64_value();
     recovery_pg_switch = config["recovery_pg_switch"].uint64_value();
     if (recovery_pg_switch < 1)
         recovery_pg_switch = DEFAULT_RECOVERY_PG_SWITCH;

src/osd.h

@@ -125,6 +125,7 @@ class osd_t
     int recovery_tune_interval = 1;
     int recovery_tune_agg_interval = 10;
     int recovery_tune_sleep_min_us = 10;
+    int recovery_tune_sleep_cutoff_us = 10000000;
     int recovery_pg_switch = DEFAULT_RECOVERY_PG_SWITCH;
     int recovery_sync_batch = DEFAULT_RECOVERY_BATCH;
     int inode_vanish_time = 60;

src/osd_flush.cpp

@@ -422,6 +422,10 @@ void osd_t::tune_recovery()
     rtune_avg_lat = total_recovery_usec/recovery_count;
     uint64_t target_lat = rtune_avg_lat * rtune_avg_lat/1000000.0 * recovery_count/recovery_tune_interval / rtune_target_util;
     auto sleep_us = target_lat > rtune_avg_lat+recovery_tune_sleep_min_us ? target_lat-rtune_avg_lat : 0;
+    if (sleep_us > recovery_tune_sleep_cutoff_us)
+    {
+        return;
+    }
     if (recovery_target_sleep_items.size() != recovery_tune_agg_interval)
     {
         recovery_target_sleep_items.resize(recovery_tune_agg_interval);