pg_prewarm: Allow autoprewarm to use more than 1GB to dump blocks.

Reported-by: Daria Shanina <vilensipkdm@gmail.com>
Author: Daria Shanina <vilensipkdm@gmail.com>
Author: Robert Haas <robertmhaas@gmail.com>
Backpatch-through: 13

diff --git a/contrib/pg_prewarm/autoprewarm.c b/contrib/pg_prewarm/autoprewarm.c
index c52f4d4dc9ea2b2a08ce1f8e206412e2059147eb..c01b9c7e6a4d669b682ac04286c9168387152431 100644 (file)
--- a/contrib/pg_prewarm/autoprewarm.c
+++ b/contrib/pg_prewarm/autoprewarm.c
@@ -693,8 +693,15 @@ apw_dump_now(bool is_bgworker, bool dump_unlogged)
                return 0;
        }
 
-       block_info_array =
-               (BlockInfoRecord *) palloc(sizeof(BlockInfoRecord) * NBuffers);
+       /*
+        * With sufficiently large shared_buffers, allocation will exceed 1GB, so
+        * allow for a huge allocation to prevent outright failure.
+        *
+        * (In the future, it might be a good idea to redesign this to use a more
+        * memory-efficient data structure.)
+        */
+       block_info_array = (BlockInfoRecord *)
+               palloc_extended((sizeof(BlockInfoRecord) * NBuffers), MCXT_ALLOC_HUGE);
 
        for (num_blocks = 0, i = 0; i < NBuffers; i++)
        {