Re: [PATCH] Make ENOSPC not fatal in semaphore creation - Mailing list pgsql-hackers

On Sun, Oct 17, 2021 at 10:52:38AM -0400, Tom Lane wrote:
> I am, however, concerned that this'll just trade off one hazard for
> another.  Instead of a risk of failing with ENOSPC (which the DBA
> can fix), we'll have a risk of kneecapping some other process at
> random (which the DBA can do nothing to prevent).

I tend to agree, and along with semas patch would like to suggest error
message improvement, it would have saved me about half a day of digging.
Tested on OpenBSD 7.0.

I'm not a native speaker though, so grammar need to be checked.

diff --git a/src/backend/port/sysv_sema.c b/src/backend/port/sysv_sema.c
index 21c883ba9a..b84f70b5e2 100644
--- a/src/backend/port/sysv_sema.c
+++ b/src/backend/port/sysv_sema.c
@@ -133,7 +133,10 @@ InternalIpcSemaphoreCreate(IpcSemaphoreKey semKey, int numSems)
                          "respective kernel parameter.  Alternatively, reduce PostgreSQL's "
                          "consumption of semaphores by reducing its max_connections parameter.\n"
                          "The PostgreSQL documentation contains more information about "
-                         "configuring your system for PostgreSQL.") : 0));
+                         "configuring your system for PostgreSQL.\n"
+                         "If server has crashed previously there may be resources left "
+                         "after it - take a look at ipcs(1) and ipcrm(1) man pages to see "
+                         "how to remove them.") : 0));
     }
 
     return semId;