YQL-20567 upgrade PG up to 16.10 & fix instructions

init
commit_hash:81aba13295273281d19d2d332a48ff1c44977447

1 files changed, 14 insertions, 4 deletions

diff --git a/yql/essentials/parser/pg_wrapper/postgresql/src/backend/postmaster/checkpointer.c b/yql/essentials/parser/pg_wrapper/postgresql/src/backend/postmaster/checkpointer.c
index e8716925919..da422229ac7 100644
--- a/yql/essentials/parser/pg_wrapper/postgresql/src/backend/postmaster/checkpointer.c
+++ b/yql/essentials/parser/pg_wrapper/postgresql/src/backend/postmaster/checkpointer.c
@@ -138,6 +138,9 @@ static __thread CheckpointerShmemStruct *CheckpointerShmem;
 /* interval for calling AbsorbSyncRequests in CheckpointWriteDelay */
 #define WRITES_PER_ABSORB		1000
 
+/* Max number of requests the checkpointer request queue can hold */
+#define MAX_CHECKPOINT_REQUESTS 10000000
+
 /*
  * GUC parameters
  */
@@ -870,11 +873,14 @@ CheckpointerShmemSize(void)
 	Size		size;
 
 	/*
-	 * Currently, the size of the requests[] array is arbitrarily set equal to
-	 * NBuffers.  This may prove too large or small ...
+	 * The size of the requests[] array is arbitrarily set equal to NBuffers.
+	 * But there is a cap of MAX_CHECKPOINT_REQUESTS to prevent accumulating
+	 * too many checkpoint requests in the ring buffer.
 	 */
 	size = offsetof(CheckpointerShmemStruct, requests);
-	size = add_size(size, mul_size(NBuffers, sizeof(CheckpointerRequest)));
+	size = add_size(size, mul_size(Min(NBuffers,
+									   MAX_CHECKPOINT_REQUESTS),
+								   sizeof(CheckpointerRequest)));
 
 	return size;
 }
@@ -903,7 +909,7 @@ CheckpointerShmemInit(void)
 		 */
 		MemSet(CheckpointerShmem, 0, size);
 		SpinLockInit(&CheckpointerShmem->ckpt_lck);
-		CheckpointerShmem->max_requests = NBuffers;
+		CheckpointerShmem->max_requests = Min(NBuffers, MAX_CHECKPOINT_REQUESTS);
 		ConditionVariableInit(&CheckpointerShmem->start_cv);
 		ConditionVariableInit(&CheckpointerShmem->done_cv);
 	}
@@ -1171,6 +1177,10 @@ CompactCheckpointerRequestQueue(void)
 	/* must hold CheckpointerCommLock in exclusive mode */
 	Assert(LWLockHeldByMe(CheckpointerCommLock));
 
+	/* Avoid memory allocations in a critical section. */
+	if (CritSectionCount > 0)
+		return false;
+
 	/* Initialize skip_slot array */
 	skip_slot = palloc0(sizeof(bool) * CheckpointerShmem->num_requests);