diff --git a/doc/src/sgml/runtime.sgml b/doc/src/sgml/runtime.sgml index 1b2012d34a9..88210c4a5d3 100644 --- a/doc/src/sgml/runtime.sgml +++ b/doc/src/sgml/runtime.sgml @@ -1120,7 +1120,7 @@ project.max-msg-ids=(priv,4096,deny) If systemd is in use, some care must be taken - that IPC resources (shared memory and semaphores) are not prematurely + that IPC resources (including shared memory) are not prematurely removed by the operating system. This is especially of concern when installing PostgreSQL from source. Users of distribution packages of PostgreSQL are less likely to be affected, as @@ -1137,11 +1137,12 @@ project.max-msg-ids=(priv,4096,deny) - A typical observed effect when this setting is on is that the semaphore - objects used by a PostgreSQL server are removed at apparently random - times, leading to the server crashing with log messages like + A typical observed effect when this setting is on is that shared memory + objects used for parallel query execution are removed at apparently random + times, leading to errors and warnings while attempting to open and remove + them, like -LOG: semctl(1234567890, 0, IPC_RMID, ...) failed: Invalid argument +WARNING: could not remove shared memory segment "/PostgreSQL.1450751626": No such file or directory Different types of IPC objects (shared memory vs. semaphores, System V vs. POSIX) are treated slightly differently