1
0
Files
linux/include/uapi/linux
Manfred Spraul e843e7d2c8 ipc/sem.c: increase SEMMSL, SEMMNI, SEMOPM
a)

SysV can be abused to allocate locked kernel memory.  For most systems, a
small limit doesn't make sense, see the discussion with regards to SHMMAX.

Therefore: Increase the sysv sem limits so that all known applications
will work with these defaults.

b)

With regards to the maximum supported:
Some of the specified hard limits are not correct anymore, therefore the
patch updates the documentation.

- SEMMNI must stay below IPCMNI, which is 32768.
  As for SHMMAX: Stay a bit below this limit.

- SEMMSL was limited to 8k, to ensure that the kmalloc for the kernel array
  was limited to 16 kB (order=2)

  This doesn't apply anymore:
   - the allocation size isn't sizeof(short)*nsems anymore.
   - ipc_alloc falls back to vmalloc

- SEMOPM should stay below 1000, to limit the kmalloc in semtimedop() to an
  order=1 allocation.
  Therefore: Leave it at 500 (order=0 allocation).

Note:
If an administrator must limit the memory allocations, then he can set the
values as necessary.

Or he can disable sysv entirely (as e.g. done by Android).

Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Acked-by: Rafael Aquini <aquini@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 12:42:52 -08:00
..
2014-09-23 23:15:46 -07:00
2014-11-24 17:31:46 -05:00
2014-10-14 13:08:29 +11:00
2014-12-09 13:34:10 -05:00
2014-07-01 10:48:05 -06:00
2014-03-20 14:55:18 +01:00
2014-11-19 14:48:02 -06:00
2014-12-08 12:55:57 +08:00
2014-08-08 15:57:31 -07:00
2014-10-24 00:14:37 +02:00
2014-05-14 10:04:34 +01:00
2013-12-11 12:57:55 -08:00
2014-12-09 12:05:30 +02:00
2014-08-08 15:57:31 -07:00
2013-11-27 11:03:38 -08:00
2014-03-04 13:51:06 -05:00
2014-06-13 10:53:49 -04:00
2014-01-06 15:13:01 -05:00
2014-03-21 14:21:13 -04:00
2014-12-10 17:41:10 -08:00
2014-04-26 12:13:24 -04:00
2014-12-09 12:05:26 +02:00
2014-12-09 12:05:26 +02:00
2014-12-09 12:05:24 +02:00
2014-12-09 12:06:31 +02:00
2014-12-09 12:05:24 +02:00
2013-12-11 09:25:20 -02:00