diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/backend/port/sysv_shmem.c | 14 | ||||
| -rw-r--r-- | src/include/port/linux.h | 15 |
2 files changed, 27 insertions, 2 deletions
diff --git a/src/backend/port/sysv_shmem.c b/src/backend/port/sysv_shmem.c index f3ff878db61..fbf5a58148e 100644 --- a/src/backend/port/sysv_shmem.c +++ b/src/backend/port/sysv_shmem.c @@ -10,7 +10,7 @@ * Portions Copyright (c) 1994, Regents of the University of California * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/port/sysv_shmem.c,v 1.47 2006/07/14 05:28:28 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/port/sysv_shmem.c,v 1.47.2.1 2007/07/02 20:12:00 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -224,6 +224,18 @@ PGSharedMemoryIsInUse(unsigned long id1, unsigned long id2) return false; /* + * Some Linux kernel versions (in fact, all of them as of July 2007) + * sometimes return EIDRM when EINVAL is correct. The Linux kernel + * actually does not have any internal state that would justify + * returning EIDRM, so we can get away with assuming that EIDRM is + * equivalent to EINVAL on that platform. + */ +#ifdef HAVE_LINUX_EIDRM_BUG + if (errno == EIDRM) + return false; +#endif + + /* * Otherwise, we had better assume that the segment is in use. The * only likely case is EIDRM, which implies that the segment has been * IPC_RMID'd but there are still processes attached to it. diff --git a/src/include/port/linux.h b/src/include/port/linux.h index 05cba063a91..191338c99fd 100644 --- a/src/include/port/linux.h +++ b/src/include/port/linux.h @@ -1 +1,14 @@ -/* $PostgreSQL: pgsql/src/include/port/linux.h,v 1.42 2006/10/04 00:30:09 momjian Exp $ */ +/* $PostgreSQL: pgsql/src/include/port/linux.h,v 1.42.2.1 2007/07/02 20:12:00 tgl Exp $ */ + +/* + * As of July 2007, all known versions of the Linux kernel will sometimes + * return EIDRM for a shmctl() operation when EINVAL is correct (it happens + * when the low-order 15 bits of the supplied shm ID match the slot number + * assigned to a newer shmem segment). We deal with this by assuming that + * EIDRM means EINVAL in PGSharedMemoryIsInUse(). This is reasonably safe + * since in fact Linux has no excuse for ever returning EIDRM; it doesn't + * track removed segments in a way that would allow distinguishing them from + * private ones. But someday that code might get upgraded, and we'd have + * to have a kernel version test here. + */ +#define HAVE_LINUX_EIDRM_BUG |