From 815c3d56638eccf9c586555dba3b273e0c745192 Mon Sep 17 00:00:00 2001
From: Sage Weil <sage@newdream.net>
Date: Wed, 10 Nov 2010 15:28:39 -0800
Subject: [PATCH] osd: fix sched_scrub

Insert whoami into reserved set on primary, not 0!  Also more cleanup of
sched state helpers.

Signed-off-by: Sage Weil <sage@newdream.net>
---
 src/osd/OSD.cc | 35 +++++++++++++++++++++++++++++++++--
 src/osd/OSD.h  |  1 +
 src/osd/PG.cc  |  6 ++----
 3 files changed, 36 insertions(+), 6 deletions(-)

diff --git a/src/osd/OSD.cc b/src/osd/OSD.cc
index 04f54b89855c7..866978a8e0836 100644
--- a/src/osd/OSD.cc
+++ b/src/osd/OSD.cc
@@ -2233,8 +2233,25 @@ bool OSD::scrub_should_schedule()
     return false;
   }
 
+  if (loadavgs[0] >= g_conf.osd_scrub_load_threshold) {
+    dout(20) << "scrub_should_schedule loadavg " << loadavgs[0]
+	     << " >= max " << g_conf.osd_scrub_load_threshold
+	     << " = no, load too high" << dendl;
+    return false;
+  }
+
+  bool coin_flip = (rand() % 3) == whoami % 3;
+  if (!coin_flip) {
+    dout(20) << "scrub_should_schedule loadavg " << loadavgs[0]
+	     << " < max " << g_conf.osd_scrub_load_threshold
+	     << " = no, randomly backing off"
+	     << dendl;
+    return false;
+  }
+  
   dout(20) << "scrub_should_schedule loadavg " << loadavgs[0]
-	   << " max " << g_conf.osd_scrub_load_threshold << dendl;
+	   << " < max " << g_conf.osd_scrub_load_threshold
+	   << " = yes" << dendl;
   return loadavgs[0] < g_conf.osd_scrub_load_threshold;
 }
 
@@ -2283,10 +2300,13 @@ bool OSD::inc_scrubs_pending()
   bool result = false;
 
   sched_scrub_lock.Lock();
-  dout(20) << "attempting to add a pending scrub with " << scrubs_pending << " scrubs_pending and " << scrubs_active << " scrubs_active and " << g_conf.osd_max_scrubs << " max scrubs " << dendl;
   if (scrubs_pending + scrubs_active < g_conf.osd_max_scrubs) {
+    dout(20) << "inc_scrubs_pending " << scrubs_pending << " -> " << (scrubs_pending+1)
+	     << " (max " << g_conf.osd_max_scrubs << ", active " << scrubs_active << ")" << dendl;
     result = true;
     ++scrubs_pending;
+  } else {
+    dout(20) << "inc_scrubs_pending " << scrubs_pending << " + " << scrubs_active << " active >= max " << g_conf.osd_max_scrubs << dendl;
   }
   sched_scrub_lock.Unlock();
 
@@ -2296,11 +2316,22 @@ bool OSD::inc_scrubs_pending()
 void OSD::dec_scrubs_pending()
 {
   sched_scrub_lock.Lock();
+  dout(20) << "dec_scrubs_pending " << scrubs_pending << " -> " << (scrubs_pending-1)
+	   << " (max " << g_conf.osd_max_scrubs << ", active " << scrubs_active << ")" << dendl;
   --scrubs_pending;
   assert(scrubs_pending >= 0);
   sched_scrub_lock.Unlock();
 }
 
+void OSD::dec_scrubs_active()
+{
+  sched_scrub_lock.Lock();
+  dout(20) << "dec_scrubs_active " << scrubs_active << " -> " << (scrubs_active-1)
+	   << " (max " << g_conf.osd_max_scrubs << ", pending " << scrubs_pending << ")" << dendl;
+  --scrubs_active;
+  sched_scrub_lock.Unlock();
+}
+
 // =====================================================
 // MAP
 
diff --git a/src/osd/OSD.h b/src/osd/OSD.h
index 4f1fb3ad67243..8e267f229a042 100644
--- a/src/osd/OSD.h
+++ b/src/osd/OSD.h
@@ -813,6 +813,7 @@ protected:
 
   bool inc_scrubs_pending();
   void dec_scrubs_pending();
+  void dec_scrubs_active();
 
   // -- scrubbing --
   xlist<PG*> scrub_queue;
diff --git a/src/osd/PG.cc b/src/osd/PG.cc
index 25f8d17375ea5..737e81bc00701 100644
--- a/src/osd/PG.cc
+++ b/src/osd/PG.cc
@@ -2579,7 +2579,7 @@ bool PG::sched_scrub()
     if (osd->inc_scrubs_pending()) {
       dout(20) << "sched_scrub: reserved locally, reserving replicas" << dendl;
       scrub_reserved = true;
-      scrub_reserved_peers.insert(0);
+      scrub_reserved_peers.insert(osd->whoami);
       scrub_reserve_replicas();
     } else {
       dout(20) << "sched_scrub: failed to reserve locally" << dendl;
@@ -3189,9 +3189,7 @@ void PG::scrub()
   update_stats();
 
   // active -> nothing.
-  osd->sched_scrub_lock.Lock();
-  --(osd->scrubs_active);
-  osd->sched_scrub_lock.Unlock();
+  osd->dec_scrubs_active();
 
   scrub_unreserve_replicas();
   
-- 
2.39.5