Do not allocate shared memory for wal_redo process (#165)

knizhnik · tristan957 · commit 403748bb8152 · 2024-02-05T12:46:04.000-06:00
* Do not allocate shared memory for wal_redo process

* Add comment
diff --git a/src/backend/port/sysv_shmem.c b/src/backend/port/sysv_shmem.c
@@ -155,6 +155,12 @@ InternalIpcMemoryCreate(IpcMemoryKey memKey, Size size)
 		}
 	}
 #endif
+	/*
+	 * NEON: do not create shared memory segments for single user wal redo postgres.
+	 * Many spawned instances of wal redo may exhaust kernel.shmmni
+	 */
+	if (am_wal_redo_postgres)
+		return valloc(size);
 
 	shmid = shmget(memKey, size, IPC_CREAT | IPC_EXCL | IPCProtection);
 

Original file line number	Diff line number	Diff line change
`@@ -155,6 +155,12 @@ InternalIpcMemoryCreate(IpcMemoryKey memKey, Size size)`
`155`	`155`	`}`
`156`	`156`	`}`
`157`	`157`	`#endif`
	`158`	`+ /*`
	`159`	`+ * NEON: do not create shared memory segments for single user wal redo postgres.`
	`160`	`+ * Many spawned instances of wal redo may exhaust kernel.shmmni`
	`161`	`+ */`
	`162`	`+ if (am_wal_redo_postgres)`
	`163`	`+ return valloc(size);`
`158`	`164`
`159`	`165`	`shmid = shmget(memKey, size, IPC_CREAT \| IPC_EXCL \| IPCProtection);`
`160`	`166`