Documentation: update sysctl/kernel.txt

Add documentation about new "msg_next_id", "sem_next_id" and "shm_next_id"
sysctls.

Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Cc: Serge Hallyn <serge.hallyn@canonical.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/Documentation/sysctl/kernel.txt b/Documentation/sysctl/kernel.txt
index 2907ba6c3607dfd557e3e4533413b0bea8518a60..51b953a1b14956f874053d233f1dda15a6ea23e9 100644 (file)
--- a/Documentation/sysctl/kernel.txt
+++ b/Documentation/sysctl/kernel.txt
@@ -38,6 +38,7 @@ show up in /proc/sys/kernel:
 - l2cr                        [ PPC only ]
 - modprobe                    ==> Documentation/debugging-modules.txt
 - modules_disabled
+- msg_next_id                [ sysv ipc ]
 - msgmax
 - msgmnb
 - msgmni
@@ -62,7 +63,9 @@ show up in /proc/sys/kernel:
 - rtsig-max
 - rtsig-nr
 - sem
+- sem_next_id                [ sysv ipc ]
 - sg-big-buff                 [ generic SCSI device (sg) ]
+- shm_next_id                [ sysv ipc ]
 - shm_rmid_forced
 - shmall
 - shmmax                      [ sysv ipc ]
@@ -320,6 +323,22 @@ to false.
 
 ==============================================================
 
+msg_next_id, sem_next_id, and shm_next_id:
+
+These three toggles allows to specify desired id for next allocated IPC
+object: message, semaphore or shared memory respectively.
+
+By default they are equal to -1, which means generic allocation logic.
+Possible values to set are in range {0..INT_MAX}.
+
+Notes:
+1) kernel doesn't guarantee, that new object will have desired id. So,
+it's up to userspace, how to handle an object with "wrong" id.
+2) Toggle with non-default value will be set back to -1 by kernel after
+successful IPC object allocation.
+
+==============================================================
+
 nmi_watchdog:
 
 Enables/Disables the NMI watchdog on x86 systems. When the value is