bk commit into 5.1 tree (hartmut:1.2248) BUG#21137

['Hartmut Holzgraefe']

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ChangeSet@stripped, 2006-08-01 17:27:44+02:00, hartmut@stripped +1 -0
  limit the max. size of allocated page chunks (Bug #21137)
  
  motivation: with the current 18% increase a table that already consumes 
  about 80% of DataMemory is likely to allocate *all* remaining RAM on 
  the next extend. Limiting the max. extend chunk size to 1024 pages 
  will increase the number of chunks for a 1GB table fragment by about 20%
  but will lead to a way more nice behavior when tables grow big and memory
  starts to become tight

  storage/ndb/src/kernel/blocks/dbtup/DbtupPageMap.cpp@stripped, 2006-08-01 17:27:40+02:00, hartmut@stripped +3 -0
    limit the max. size of allocated page chunks (Bug #21137)

# This is a BitKeeper patch.  What follows are the unified diffs for the
# set of deltas contained in the patch.  The rest of the patch, the part
# that BitKeeper cares about, is below these diffs.
# User:	hartmut
# Host:	linux.site
# Root:	/home/hartmut/projects/mysql/dev/5.1-alloc-limit

--- 1.8/storage/ndb/src/kernel/blocks/dbtup/DbtupPageMap.cpp	2006-08-01 17:27:52 +02:00
+++ 1.9/storage/ndb/src/kernel/blocks/dbtup/DbtupPageMap.cpp	2006-08-01 17:27:52 +02:00
@@ -435,7 +435,10 @@
 /* -----------------------------------------------------------------*/
 // We will grow by 18.75% plus two more additional pages to grow
 // a little bit quicker in the beginning.
+// Once reaching a chunk size of 1024 pages we don't grow beyond
+// that anymore to prevent over-agressive allocation 
 /* -----------------------------------------------------------------*/
+  if (noAllocPages > 1024) noAllocPages = 1024; 
   allocFragPages(regFragPtr, noAllocPages);
 }//Dbtup::allocMoreFragPages()