From: Sage Weil <sage.weil@dreamhost.com>
Date: Thu, 2 Feb 2012 21:48:26 +0000 (-0800)
Subject: encoding: document ENCODE_DUMP throttling weirdness
X-Git-Tag: v0.44~93^2~3
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=a0dde42287144cb410ce9602cabd389437c19203;p=ceph.git

encoding: document ENCODE_DUMP throttling weirdness

Signed-off-by: Sage Weil <sage.weil@dreamhost.com>
---

diff --git a/src/include/encoding.h b/src/include/encoding.h
index 451e287ab67d..f304502082ff 100644
--- a/src/include/encoding.h
+++ b/src/include/encoding.h
@@ -114,6 +114,9 @@ WRITE_INTTYPE_ENCODER(int16_t, le16)
 
 # define ENCODE_DUMP_PRE()			\
   unsigned pre_off = bl.length()
+
+// NOTE: This is almost an exponential backoff, but because we count
+// bits we get a better sample of things we encode later on.
 # define ENCODE_DUMP_POST(cl)						\
   do {									\
     static int i = 0;							\
diff --git a/src/msg/Message.cc b/src/msg/Message.cc
index 6be198df6b8b..50330a335256 100644
--- a/src/msg/Message.cc
+++ b/src/msg/Message.cc
@@ -166,6 +166,9 @@ void Message::encode(uint64_t features, bool datacrc)
     ::encode(get_middle(), bl);
     ::encode(get_data(), bl);
 
+    // this is almost an exponential backoff, except because we count
+    // bits we tend to sample things we encode later, which should be
+    // more representative.
     static int i = 0;
     i++;
     int bits = 0;