diff options
| -rw-r--r-- | src/backend/storage/buffer/freelist.c | 15 |
1 files changed, 11 insertions, 4 deletions
diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 7db8b766aaa..333053c1c93 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -9,7 +9,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/storage/buffer/freelist.c,v 1.55 2006/03/05 15:58:36 momjian Exp $ + * $PostgreSQL: pgsql/src/backend/storage/buffer/freelist.c,v 1.56 2006/07/23 18:34:45 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -213,8 +213,8 @@ StrategyShmemSize(void) { Size size = 0; - /* size of lookup hash table */ - size = add_size(size, BufTableShmemSize(NBuffers)); + /* size of lookup hash table ... see comment in StrategyInitialize */ + size = add_size(size, BufTableShmemSize(NBuffers + NUM_BUFFER_PARTITIONS)); /* size of the shared replacement strategy control block */ size = add_size(size, MAXALIGN(sizeof(BufferStrategyControl))); @@ -236,8 +236,15 @@ StrategyInitialize(bool init) /* * Initialize the shared buffer lookup hashtable. + * + * Since we can't tolerate running out of lookup table entries, we + * must be sure to specify an adequate table size here. The maximum + * steady-state usage is of course NBuffers entries, but BufferAlloc() + * tries to insert a new entry before deleting the old. In principle + * this could be happening in each partition concurrently, so we + * could need as many as NBuffers + NUM_BUFFER_PARTITIONS entries. */ - InitBufTable(NBuffers); + InitBufTable(NBuffers + NUM_BUFFER_PARTITIONS); /* * Get or create the shared strategy control block |