Changeset: bce0487c1dad for MonetDB
URL: https://dev.monetdb.org/hg/MonetDB/rev/bce0487c1dad
Modified Files:
monetdb5/mal/mal_instruction.c
Branch: default
Log Message:
Use chunk based extensions for stmt/var to reduce memory fragmentation occurring
diffs (63 lines):
diff --git a/monetdb5/mal/mal_instruction.c b/monetdb5/mal/mal_instruction.c
--- a/monetdb5/mal/mal_instruction.c
+++ b/monetdb5/mal/mal_instruction.c
@@ -17,6 +17,9 @@
#include "mal_exception.h"
#include "mal_private.h"
+/* to avoid memory fragmentation stmt and var blocks are allocated in chunks */
+#define MALCHUNK 32
+
/* If we encounter an error it can be left behind in the MalBlk
* for the upper layers to abandon the track
*/
@@ -86,6 +89,7 @@ int
newMalBlkStmt(MalBlkPtr mb, int maxstmts)
{
InstrPtr *p;
+ maxstmts= (maxstmts / MALCHUNK + 1) * MALCHUNK;
p = (InstrPtr *) GDKzalloc(sizeof(InstrPtr) * maxstmts);
if (p == NULL)
@@ -108,7 +112,8 @@ newMalBlk(int elements)
/* each MAL instruction implies at least one variable
* we reserve some extra for constants */
- v = (VarRecord *) GDKzalloc(sizeof(VarRecord) * (elements + 8) );
+ elements= ((elements + 8) / MALCHUNK + 1) * MALCHUNK;
+ v = (VarRecord *) GDKzalloc(sizeof(VarRecord) * elements );
if (v == NULL) {
GDKfree(mb);
return NULL;
@@ -147,20 +152,14 @@ newMalBlk(int elements)
/* We only grow until the MAL block can be used */
static int growBlk(int elm)
{
- int steps =1 ;
- int old = elm;
-
- while( old / 2 > 1){
- old /= 2;
- steps++;
- }
- return elm + steps * STMT_INCREMENT;
+ return (elm / MALCHUNK + 1) * MALCHUNK;
}
int
resizeMalBlk(MalBlkPtr mb, int elements)
{
int i;
+ elements = (elements / MALCHUNK + 1) * MALCHUNK;
if( elements > mb->ssize){
InstrPtr *ostmt = mb->stmt;
@@ -1395,7 +1394,7 @@ pushInstruction(MalBlkPtr mb, InstrPtr p
extra = mb->vsize - mb->vtop; // the extra variables already known
if (mb->stop + 1 >= mb->ssize) {
- if( resizeMalBlk(mb, growBlk(mb->ssize) + extra) ){
+ if( resizeMalBlk(mb, growBlk(mb->ssize + extra)) ){
/* perhaps we can continue with a smaller increment.
* But the block remains marked as faulty.
*/
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