From: Samuel Just <sam.just@inktank.com>
Date: Tue, 31 Jul 2012 16:04:40 +0000 (-0700)
Subject: JournalingFileStore: pass -1 as the alignment if unimportant
X-Git-Tag: v0.55~130^2~41^2~15
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=5326c2212ad173449a5c46bd05d07d3cb0cee844;p=ceph.git

JournalingFileStore: pass -1 as the alignment if unimportant

Previously, data_align began at 0 and remained that way if no
transaction contained a large data segment.  This 0 was propagated
to prepare_single_write, which padded out most of a page to ensure
that the bl started with 0 alignment.  Passing -1 will ensure that
we don't prepad these small segments.

Signed-off-by: Samuel Just <sam.just@inktank.com>
---

diff --git a/src/os/JournalingObjectStore.cc b/src/os/JournalingObjectStore.cc
index 83864fc00cc..e1e077e7751 100644
--- a/src/os/JournalingObjectStore.cc
+++ b/src/os/JournalingObjectStore.cc
@@ -290,7 +290,8 @@ void JournalingObjectStore::_op_journal_transactions(list<ObjectStore::Transacti
     
   if (journal && journal->is_writeable()) {
     bufferlist tbl;
-    unsigned data_len = 0, data_align = 0;
+    unsigned data_len = 0;
+    int data_align = -1; // -1 indicates that we don't care about the alignment
     for (list<ObjectStore::Transaction*>::iterator p = tls.begin(); p != tls.end(); p++) {
       ObjectStore::Transaction *t = *p;
       if (t->get_data_length() > data_len &&