| From: Robin Holt <holt@sgi.com> |
| Date: Tue, 30 Apr 2013 19:15:54 -0700 |
| Subject: ipc: sysv shared memory limited to 8TiB |
| |
| commit d69f3bad4675ac519d41ca2b11e1c00ca115cecd upstream. |
| |
| Trying to run an application which was trying to put data into half of |
| memory using shmget(), we found that having a shmall value below 8EiB-8TiB |
| would prevent us from using anything more than 8TiB. By setting |
| kernel.shmall greater than 8EiB-8TiB would make the job work. |
| |
| In the newseg() function, ns->shm_tot which, at 8TiB is INT_MAX. |
| |
| ipc/shm.c: |
| 458 static int newseg(struct ipc_namespace *ns, struct ipc_params *params) |
| 459 { |
| ... |
| 465 int numpages = (size + PAGE_SIZE -1) >> PAGE_SHIFT; |
| ... |
| 474 if (ns->shm_tot + numpages > ns->shm_ctlall) |
| 475 return -ENOSPC; |
| |
| [akpm@linux-foundation.org: make ipc/shm.c:newseg()'s numpages size_t, not int] |
| Signed-off-by: Robin Holt <holt@sgi.com> |
| Reported-by: Alex Thorlton <athorlton@sgi.com> |
| Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
| Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
| Signed-off-by: Ben Hutchings <ben@decadent.org.uk> |
| --- |
| include/linux/ipc_namespace.h | 2 +- |
| ipc/shm.c | 2 +- |
| 2 files changed, 2 insertions(+), 2 deletions(-) |
| |
| --- a/include/linux/ipc_namespace.h |
| +++ b/include/linux/ipc_namespace.h |
| @@ -42,8 +42,8 @@ struct ipc_namespace { |
| |
| size_t shm_ctlmax; |
| size_t shm_ctlall; |
| + unsigned long shm_tot; |
| int shm_ctlmni; |
| - int shm_tot; |
| /* |
| * Defines whether IPC_RMID is forced for _all_ shm segments regardless |
| * of shmctl() |
| --- a/ipc/shm.c |
| +++ b/ipc/shm.c |
| @@ -450,7 +450,7 @@ static int newseg(struct ipc_namespace * |
| size_t size = params->u.size; |
| int error; |
| struct shmid_kernel *shp; |
| - int numpages = (size + PAGE_SIZE -1) >> PAGE_SHIFT; |
| + size_t numpages = (size + PAGE_SIZE - 1) >> PAGE_SHIFT; |
| struct file * file; |
| char name[13]; |
| int id; |