[CF 7548] v2 - Fall back to serializing when parallel apply runs out of DSM segments

This branch was automatically generated by a robot using patches from an
email thread registered at:

https://commitfest.postgresql.org/patch/7548

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Patch(es): https://www.postgresql.org/message-id/CA+fm-RNBhpKnPArvZj-Ev8A8wD-vi3dkM1g-YM0KSysKin8Veg@mail.gmail.com
Author(s): Baji Shaik

Author: Commitfest Bot

src/backend/replication/logical/applyparallelworker.c

@@ -358,7 +358,7 @@ pa_setup_dsm(ParallelApplyWorkerInfo *winfo)
 	segsize = shm_toc_estimate(&e);
 
 	/* Create the shared memory segment and establish a table of contents. */
-	seg = dsm_create(shm_toc_estimate(&e), 0);
+	seg = dsm_create(shm_toc_estimate(&e), DSM_CREATE_NULL_IF_MAXSEGMENTS);
 	if (!seg)
 		return false;
 

src/backend/utils/mmgr/dsa.c

@@ -2247,7 +2247,7 @@ make_new_segment(dsa_area *area, size_t requested_pages)
 	/* Create the segment. */
 	oldowner = CurrentResourceOwner;
 	CurrentResourceOwner = area->resowner;
-	segment = dsm_create(total_size, 0);
+	segment = dsm_create(total_size, DSM_CREATE_NULL_IF_MAXSEGMENTS);
 	CurrentResourceOwner = oldowner;
 	if (segment == NULL)
 		return NULL;