postgres.git / summary / log / commit / refs

commit    bfaa8c665fcbd4388e01c53c4b5137f1f53d1787
Author:   Kevin Grittner <kgrittn@postgresql.org>
Date:     Thu Jun 19 13:40:37 2014 +0000
First released in: 9.5.0, 9.4.0

    Fix calculation of PREDICATELOCK_MANAGER_LWLOCK_OFFSET.
    
    Commit ea9df812d8502fff74e7bc37d61bdc7d66d77a7f failed to include
    NUM_BUFFER_PARTITIONS in this offset, resulting in a bad offset.
    Ultimately this threw off NUM_FIXED_LWLOCKS which is based on
    earlier offsets, leading to memory allocation problems.  It seems
    likely to have also caused increased LWLOCK contention when
    serializable transactions were used, because lightweight locks used
    for that overlapped others.
    
    Reported by Amit Kapila with analysis and fix.
    Backpatch to 9.4, where the bug was introduced.


 src/include/storage/lwlock.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/include/storage/lwlock.h b/src/include/storage/lwlock.h
index 175fae3a88b..d588b1434e2 100644
--- a/src/include/storage/lwlock.h
+++ b/src/include/storage/lwlock.h
@@ -151,7 +151,7 @@ extern PGDLLIMPORT LWLockPadded *MainLWLockArray;
 #define LOCK_MANAGER_LWLOCK_OFFSET		\
 	(BUFFER_MAPPING_LWLOCK_OFFSET + NUM_BUFFER_PARTITIONS)
 #define PREDICATELOCK_MANAGER_LWLOCK_OFFSET \
-	(NUM_INDIVIDUAL_LWLOCKS + NUM_LOCK_PARTITIONS)
+	(LOCK_MANAGER_LWLOCK_OFFSET + NUM_LOCK_PARTITIONS)
 #define NUM_FIXED_LWLOCKS \
 	(PREDICATELOCK_MANAGER_LWLOCK_OFFSET + NUM_PREDICATELOCK_PARTITIONS)
 


[parent: 9ba78fb0b9e6]