diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index 3025d0badb..079e1814c1 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -7719,10 +7719,15 @@ StartupXLOG(void)
 	 * Update full_page_writes in shared memory and write an XLOG_FPW_CHANGE
 	 * record before resource manager writes cleanup WAL records or checkpoint
 	 * record is written.
+	 *
+	 * It is safe to check the shared full_page_writes without the lock,
+	 * because there is no concurrently running process able to update it.
+	 * The only other process able to update full_page_writes is the
+	 * checkpointer, still it is unable to do so until recovery finishes.
 	 */
 	Insert->fullPageWrites = lastFullPageWrites;
 	LocalSetXLogInsertAllowed();
-	UpdateFullPageWrites();
+	UpdateFullPageWrites(true);
 	LocalXLogInsertAllowed = -1;
 
 	if (InRecovery)
@@ -9693,14 +9698,28 @@ XLogReportParameters(void)
  * Update full_page_writes in shared memory, and write an
  * XLOG_FPW_CHANGE record if necessary.
  *
- * Note: this function assumes there is no other process running
- * concurrently that could update it.
+ * Note: this can be called from the checkpointer, or the startup process
+ * at the end of recovery.  One could think that this routine should be
+ * careful with its lock handling, however this is a no-op for the
+ * checkpointer until the startup process marks the end of recovery,
+ * so only one of them can do the work of this routine at once.
  */
 void
-UpdateFullPageWrites(void)
+UpdateFullPageWrites(bool force)
 {
 	XLogCtlInsert *Insert = &XLogCtl->Insert;
 
+	/*
+	 * Check if recovery is still in progress before entering this critical
+	 * section, as some memory allocation could happen at the end of
+	 * recovery.  There is nothing to do for a system still in recovery.
+	 * Note that the caller may still want to enforce an update to happen.
+	 * One such example is the startup process, which updates full_page_writes
+	 * at the end of recovery.
+	 */
+	if (RecoveryInProgress() && !force)
+		return;
+
 	/*
 	 * Do nothing if full_page_writes has not been changed.
 	 *
@@ -9731,7 +9750,7 @@ UpdateFullPageWrites(void)
 	 * Write an XLOG_FPW_CHANGE record. This allows us to keep track of
 	 * full_page_writes during archive recovery, if required.
 	 */
-	if (XLogStandbyInfoActive() && !RecoveryInProgress())
+	if (XLogStandbyInfoActive())
 	{
 		XLogBeginInsert();
 		XLogRegisterData((char *) (&fullPageWrites), sizeof(bool));
diff --git a/src/backend/postmaster/checkpointer.c b/src/backend/postmaster/checkpointer.c
index 1a033093c5..2084978468 100644
--- a/src/backend/postmaster/checkpointer.c
+++ b/src/backend/postmaster/checkpointer.c
@@ -1347,7 +1347,7 @@ UpdateSharedMemoryConfig(void)
 	 * If full_page_writes has been changed by SIGHUP, we update it in shared
 	 * memory and write an XLOG_FPW_CHANGE record.
 	 */
-	UpdateFullPageWrites();
+	UpdateFullPageWrites(false);
 
 	elog(DEBUG2, "checkpointer updated shared memory configuration values");
 }
diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h
index 421ba6d775..7cfed58399 100644
--- a/src/include/access/xlog.h
+++ b/src/include/access/xlog.h
@@ -270,7 +270,7 @@ extern void CreateCheckPoint(int flags);
 extern bool CreateRestartPoint(int flags);
 extern void XLogPutNextOid(Oid nextOid);
 extern XLogRecPtr XLogRestorePoint(const char *rpName);
-extern void UpdateFullPageWrites(void);
+extern void UpdateFullPageWrites(bool force);
 extern void GetFullPageWriteInfo(XLogRecPtr *RedoRecPtr_p, bool *doPageWrites_p);
 extern XLogRecPtr GetRedoRecPtr(void);
 extern XLogRecPtr GetInsertRecPtr(void);