kraken: osd: Implement asynchronous scrub sleep

src/osd/OSD.cc

@@ -262,6 +262,9 @@ OSDService::OSDService(OSD *osd) :
     osd->client_messenger->cct, snap_sleep_lock, false /* relax locking */),
   snap_reserver(&reserver_finisher,
 		cct->_conf->osd_max_trimming_pgs),
+  scrub_sleep_lock("OSDService::scrub_sleep_lock"),
+  scrub_sleep_timer(
+    osd->client_messenger->cct, scrub_sleep_lock, false /* relax locking */),
   recovery_lock("OSDService::recovery_lock"),
   recovery_ops_active(0),
   recovery_ops_reserved(0),
@@ -537,6 +540,11 @@ void OSDService::shutdown()
     snap_sleep_timer.shutdown();
   }
 
+  {
+    Mutex::Locker l(scrub_sleep_lock);
+    scrub_sleep_timer.shutdown();
+  }
+
   osdmap = OSDMapRef();
   next_osdmap = OSDMapRef();
 }
@@ -549,6 +557,7 @@ void OSDService::init()
   watch_timer.init();
   agent_timer.init();
   snap_sleep_timer.init();
+  scrub_sleep_timer.init();
 
   agent_thread.create("osd_srv_agent");
 
@@ -3334,6 +3343,11 @@ PG *OSD::_lookup_lock_pg(spg_t pgid)
   return pg;
 }
 
+PG *OSD::lookup_lock_pg(spg_t pgid)
+{
+  return _lookup_lock_pg(pgid);
+}
+
 PG *OSD::_lookup_lock_pg_with_map_lock_held(spg_t pgid)
 {
   assert(pg_map.count(pgid));

src/osd/OSD.h

@@ -894,6 +894,10 @@ class OSDService {
   SafeTimer snap_sleep_timer;
 
   AsyncReserver<spg_t> snap_reserver;
+
+  Mutex scrub_sleep_lock;
+  SafeTimer scrub_sleep_timer;
+
   void queue_for_snap_trim(PG *pg);
 
   void queue_for_scrub(PG *pg) {
@@ -2012,6 +2016,11 @@ class OSD : public Dispatcher,
 			       Session *session);
   PG   *_lookup_lock_pg_with_map_lock_held(spg_t pgid);
   PG   *_lookup_lock_pg(spg_t pgid);
+
+public:
+  PG   *lookup_lock_pg(spg_t pgid);
+
+protected:
   PG   *_open_lock_pg(OSDMapRef createmap,
 		      spg_t pg, bool no_lockdep_check=false);
   enum res_result {

src/osd/PG.cc

@@ -4065,22 +4065,49 @@ void PG::scrub(epoch_t queued, ThreadPool::TPHandle &handle)
 {
   if (g_conf->osd_scrub_sleep > 0 &&
       (scrubber.state == PG::Scrubber::NEW_CHUNK ||
-       scrubber.state == PG::Scrubber::INACTIVE)) {
+       scrubber.state == PG::Scrubber::INACTIVE) &&
+       scrubber.needs_sleep) {
+    ceph_assert(!scrubber.sleeping);
     dout(20) << __func__ << " state is INACTIVE|NEW_CHUNK, sleeping" << dendl;
-    unlock();
-    utime_t t;
-    t.set_from_double(g_conf->osd_scrub_sleep);
-    handle.suspend_tp_timeout();
-    t.sleep();
-    handle.reset_tp_timeout();
-    lock();
-    dout(20) << __func__ << " slept for " << t << dendl;
+
+    // Do an async sleep so we don't block the op queue
+    OSDService *osds = osd;
+    spg_t pgid = get_pgid();
+    int state = scrubber.state;
+    auto scrub_requeue_callback =
+        new FunctionContext([osds, pgid, state](int r) {
+          PG *pg = osds->osd->lookup_lock_pg(pgid);
+          if (pg == nullptr) {
+            lgeneric_dout(osds->osd->cct, 20)
+                << "scrub_requeue_callback: Could not find "
+                << "PG " << pgid << " can't complete scrub requeue after sleep"
+                << dendl;
+            return;
+          }
+          pg->scrubber.sleeping = false;
+          pg->scrubber.needs_sleep = false;
+          lgeneric_dout(pg->cct, 20)
+              << "scrub_requeue_callback: slept for "
+              << ceph_clock_now() - pg->scrubber.sleep_start
+              << ", re-queuing scrub with state " << state << dendl;
+          pg->scrub_queued = false;
+          pg->requeue_scrub();
+          pg->scrubber.sleep_start = utime_t();
+          pg->unlock();
+        });
+    Mutex::Locker l(osd->scrub_sleep_lock);
+    osd->scrub_sleep_timer.add_event_after(cct->_conf->osd_scrub_sleep,
+                                           scrub_requeue_callback);
+    scrubber.sleeping = true;
+    scrubber.sleep_start = ceph_clock_now();
+    return;
   }
   if (pg_has_reset_since(queued)) {
     return;
   }
   assert(scrub_queued);
   scrub_queued = false;
+  scrubber.needs_sleep = true;
 
   if (!is_primary() || !is_active() || !is_clean() || !is_scrubbing()) {
     dout(10) << "scrub -- not primary or active or not clean" << dendl;

src/osd/PG.h

@@ -34,6 +34,7 @@
 #include "osd_types.h"
 #include "include/xlist.h"
 #include "SnapMapper.h"
+#include "common/Timer.h"
 
 #include "PGLog.h"
 #include "OSDMap.h"
@@ -872,7 +873,6 @@ class PG : protected DoutPrefixProvider {
 public:
   void clear_primary_state();
 
- public:
   bool is_actingbackfill(pg_shard_t osd) const {
     return actingbackfill.count(osd);
   }
@@ -1101,6 +1101,11 @@ class PG : protected DoutPrefixProvider {
     OpRequestRef active_rep_scrub;
     utime_t scrub_reg_stamp;  // stamp we registered for
 
+    // For async sleep
+    bool sleeping = false;
+    bool needs_sleep = true;
+    utime_t sleep_start;
+
     // flags to indicate explicitly requested scrubs (by admin)
     bool must_scrub, must_deep_scrub, must_repair;
 
@@ -1219,6 +1224,9 @@ class PG : protected DoutPrefixProvider {
       authoritative.clear();
       num_digest_updates_pending = 0;
       cleaned_meta_map = ScrubMap();
+      sleeping = false;
+      needs_sleep = true;
+      sleep_start = utime_t();
     }
 
     void create_results(const hobject_t& obj);