diff options
Diffstat (limited to 'src/backend/port/sysv_shmem.c')
| -rw-r--r-- | src/backend/port/sysv_shmem.c | 30 |
1 files changed, 18 insertions, 12 deletions
diff --git a/src/backend/port/sysv_shmem.c b/src/backend/port/sysv_shmem.c index ac3a9fe3b0b..65ad59570cb 100644 --- a/src/backend/port/sysv_shmem.c +++ b/src/backend/port/sysv_shmem.c @@ -73,15 +73,17 @@ InternalIpcMemoryCreate(IpcMemoryKey memKey, Size size) if (shmid < 0) { + int shmget_errno = errno; + /* * Fail quietly if error indicates a collision with existing segment. * One would expect EEXIST, given that we said IPC_EXCL, but perhaps * we could get a permission violation instead? Also, EIDRM might * occur if an old seg is slated for destruction but not gone yet. */ - if (errno == EEXIST || errno == EACCES + if (shmget_errno == EEXIST || shmget_errno == EACCES #ifdef EIDRM - || errno == EIDRM + || shmget_errno == EIDRM #endif ) return NULL; @@ -95,10 +97,8 @@ InternalIpcMemoryCreate(IpcMemoryKey memKey, Size size) * against SHMMIN in the preexisting-segment case, so we will not get * EINVAL a second time if there is such a segment. */ - if (errno == EINVAL) + if (shmget_errno == EINVAL) { - int save_errno = errno; - shmid = shmget(memKey, 0, IPC_CREAT | IPC_EXCL | IPCProtection); if (shmid < 0) @@ -124,8 +124,6 @@ InternalIpcMemoryCreate(IpcMemoryKey memKey, Size size) elog(LOG, "shmctl(%d, %d, 0) failed: %m", (int) shmid, IPC_RMID); } - - errno = save_errno; } /* @@ -137,25 +135,26 @@ InternalIpcMemoryCreate(IpcMemoryKey memKey, Size size) * it should be. SHMMNI violation is ENOSPC, per spec. Just plain * not-enough-RAM is ENOMEM. */ + errno = shmget_errno; ereport(FATAL, (errmsg("could not create shared memory segment: %m"), errdetail("Failed system call was shmget(key=%lu, size=%zu, 0%o).", (unsigned long) memKey, size, IPC_CREAT | IPC_EXCL | IPCProtection), - (errno == EINVAL) ? + (shmget_errno == EINVAL) ? errhint("This error usually means that PostgreSQL's request for a shared memory " "segment exceeded your kernel's SHMMAX parameter, or possibly that " "it is less than " "your kernel's SHMMIN parameter.\n" "The PostgreSQL documentation contains more information about shared " "memory configuration.") : 0, - (errno == ENOMEM) ? + (shmget_errno == ENOMEM) ? errhint("This error usually means that PostgreSQL's request for a shared " "memory segment exceeded your kernel's SHMALL parameter. You might need " "to reconfigure the kernel with larger SHMALL.\n" "The PostgreSQL documentation contains more information about shared " "memory configuration.") : 0, - (errno == ENOSPC) ? + (shmget_errno == ENOSPC) ? errhint("This error does *not* mean that you have run out of disk space. " "It occurs either if all available shared memory IDs have been taken, " "in which case you need to raise the SHMMNI parameter in your kernel, " @@ -331,6 +330,7 @@ CreateAnonymousSegment(Size *size) { Size allocsize = *size; void *ptr = MAP_FAILED; + int mmap_errno = 0; #ifndef MAP_HUGETLB if (huge_tlb_pages == HUGE_TLB_ON) @@ -363,6 +363,7 @@ CreateAnonymousSegment(Size *size) ptr = mmap(NULL, allocsize, PROT_READ | PROT_WRITE, PG_MMAP_FLAGS | MAP_HUGETLB, -1, 0); + mmap_errno = errno; if (huge_tlb_pages == HUGE_TLB_TRY && ptr == MAP_FAILED) elog(DEBUG1, "mmap with MAP_HUGETLB failed, huge pages disabled: %m"); } @@ -376,13 +377,17 @@ CreateAnonymousSegment(Size *size) * back to non-huge pages. */ allocsize = *size; - ptr = mmap(NULL, allocsize, PROT_READ | PROT_WRITE, PG_MMAP_FLAGS, -1, 0); + ptr = mmap(NULL, allocsize, PROT_READ | PROT_WRITE, + PG_MMAP_FLAGS, -1, 0); + mmap_errno = errno; } if (ptr == MAP_FAILED) + { + errno = mmap_errno; ereport(FATAL, (errmsg("could not map anonymous shared memory: %m"), - (errno == ENOMEM) ? + (mmap_errno == ENOMEM) ? errhint("This error usually means that PostgreSQL's request " "for a shared memory segment exceeded available memory, " "swap space or huge pages. To reduce the request size " @@ -390,6 +395,7 @@ CreateAnonymousSegment(Size *size) "memory usage, perhaps by reducing shared_buffers or " "max_connections.", *size) : 0)); + } *size = allocsize; return ptr; |