Improve postmaster's behavior if an accept() call fails. Because the server

socket is still read-ready, the code was a tight loop, wasting lots of CPU.
We can't do anything to clear the failure, other than wait, but we should give
other processes more chance to finish and release FDs; so insert a small sleep.
Also, avoid bogus "close(-1)" in this case.  Per report from Jim Nasby.
This commit is contained in:
Tom Lane 2007-02-13 19:18:54 +00:00
parent b9c65aed82
commit cf4cc7843c
2 changed files with 13 additions and 4 deletions

View File

@ -30,7 +30,7 @@
* Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group * Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California * Portions Copyright (c) 1994, Regents of the University of California
* *
* $PostgreSQL: pgsql/src/backend/libpq/pqcomm.c,v 1.189 2007/01/05 22:19:29 momjian Exp $ * $PostgreSQL: pgsql/src/backend/libpq/pqcomm.c,v 1.190 2007/02/13 19:18:53 tgl Exp $
* *
*------------------------------------------------------------------------- *-------------------------------------------------------------------------
*/ */
@ -528,7 +528,7 @@ Setup_AF_UNIX(void)
/* /*
* StreamConnection -- create a new connection with client using * StreamConnection -- create a new connection with client using
* server port. * server port. Set port->sock to the FD of the new connection.
* *
* ASSUME: that this doesn't need to be non-blocking because * ASSUME: that this doesn't need to be non-blocking because
* the Postmaster uses select() to tell when the server master * the Postmaster uses select() to tell when the server master
@ -548,6 +548,14 @@ StreamConnection(int server_fd, Port *port)
ereport(LOG, ereport(LOG,
(errcode_for_socket_access(), (errcode_for_socket_access(),
errmsg("could not accept new connection: %m"))); errmsg("could not accept new connection: %m")));
/*
* If accept() fails then postmaster.c will still see the server
* socket as read-ready, and will immediately try again. To avoid
* uselessly sucking lots of CPU, delay a bit before trying again.
* (The most likely reason for failure is being out of kernel file
* table slots; we can do little except hope some will get freed up.)
*/
pg_usleep(100000L); /* wait 0.1 sec */
return STATUS_ERROR; return STATUS_ERROR;
} }

View File

@ -37,7 +37,7 @@
* *
* *
* IDENTIFICATION * IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/postmaster/postmaster.c,v 1.520 2007/02/11 11:59:25 mha Exp $ * $PostgreSQL: pgsql/src/backend/postmaster/postmaster.c,v 1.521 2007/02/13 19:18:54 tgl Exp $
* *
* NOTES * NOTES
* *
@ -1710,7 +1710,8 @@ ConnCreate(int serverFd)
if (StreamConnection(serverFd, port) != STATUS_OK) if (StreamConnection(serverFd, port) != STATUS_OK)
{ {
StreamClose(port->sock); if (port->sock >= 0)
StreamClose(port->sock);
ConnFree(port); ConnFree(port);
port = NULL; port = NULL;
} }