linux/ipc/util.c, branch v2.6.26

sysvipc: use non-racy method for proc entries creation

2008-04-29T15:06:20Z

Use proc_create_data() to make sure that ->proc_fops and ->data be setup before gluing PDE to main tree. Signed-off-by: Denis V. Lunev Cc: Alexey Dobriyan Cc: "Eric W. Biederman" Cc: Nadia Derbey Cc: Pierre Peiffer Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

ipc: add definitions of USHORT_MAX and others

2008-04-29T15:06:14Z

Add definitions of USHORT_MAX and others into kernel. ipc uses it and slub implementation might also use it. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Zhang Yanmin Reviewed-by: Christoph Lameter Cc: Nadia Derbey Cc: "Pierre Peiffer" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

IPC: consolidate all xxxctl_down() functions

2008-04-29T15:06:14Z

semctl_down(), msgctl_down() and shmctl_down() are used to handle the same set of commands for each kind of IPC. They all start to do the same job (they retrieve the ipc and do some permission checks) before handling the commands on their own. This patch proposes to consolidate this by moving these same pieces of code into one common function called ipcctl_pre_down(). It simplifies a little these xxxctl_down() functions and increases a little the maintainability. Signed-off-by: Pierre Peiffer Acked-by: Serge Hallyn Cc: Nadia Derbey Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

IPC: introduce ipc_update_perm()

2008-04-29T15:06:13Z

The IPC_SET command performs the same permission setting for all IPCs. This patch introduces a common ipc_update_perm() function to update these permissions and makes use of it for all IPCs. Signed-off-by: Pierre Peiffer Acked-by: Serge Hallyn Cc: Nadia Derbey Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

ipc: invoke the ipcns notifier chain as a work item

2008-04-29T15:06:12Z

Make the memory hotplug chain's mutex held for a shorter time: when memory is offlined or onlined a work item is added to the global workqueue. When the work item is run, it notifies the ipcns notifier chain with the IPCNS_MEMCHANGED event. Signed-off-by: Nadia Derbey Cc: Yasunori Goto Cc: Matt Helsley Cc: Mingming Cao Cc: Pierre Peiffer Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

ipc: recompute msgmni on memory add / remove

2008-04-29T15:06:12Z

Introduce the registration of a callback routine that recomputes msg_ctlmni upon memory add / remove. A single notifier block is registered in the hotplug memory chain for all the ipc namespaces. Since the ipc namespaces are not linked together, they have their own notification chain: one notifier_block is defined per ipc namespace. Each time an ipc namespace is created (removed) it registers (unregisters) its notifier block in (from) the ipcns chain. The callback routine registered in the memory chain invokes the ipcns notifier chain with the IPCNS_LOWMEM event. Each callback routine registered in the ipcns namespace, in turn, recomputes msgmni for the owning namespace. Signed-off-by: Nadia Derbey Cc: Yasunori Goto Cc: Matt Helsley Cc: Mingming Cao Cc: Pierre Peiffer Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

ipc: scale msgmni to the number of ipc namespaces

2008-04-29T15:06:12Z

Since all the namespaces see the same amount of memory (the total one) this patch introduces a new variable that counts the ipc namespaces and divides msg_ctlmni by this counter. Signed-off-by: Nadia Derbey Cc: Yasunori Goto Cc: Matt Helsley Cc: Mingming Cao Cc: Pierre Peiffer Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

IPC: use ipc_buildid() directly from ipc_addid()

2008-04-29T15:06:12Z

By continuing to consolidate a little the IPC code, each id can be built directly in ipc_addid() instead of having it built from each callers of ipc_addid() And I also remove shm_addid() in order to have, as much as possible, the same code for shm/sem/msg. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Pierre Peiffer Cc: Nadia Derbey Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

IPC: make struct ipc_ids static in ipc_namespace

2008-02-08T17:22:26Z

Each ipc_namespace contains a table of 3 pointers to struct ipc_ids (3 for msg, sem and shm, structure used to store all ipcs) These 'struct ipc_ids' are dynamically allocated for each icp_namespace as the ipc_namespace itself (for the init namespace, they are initialized with pointers to static variables instead) It is so for historical reason: in fact, before the use of idr to store the ipcs, the ipcs were stored in tables of variable length, depending of the maximum number of ipc allowed. Now, these 'struct ipc_ids' have a fixed size. As they are allocated in any cases for each new ipc_namespace, there is no gain of memory in having them allocated separately of the struct ipc_namespace. This patch proposes to make this table static in the struct ipc_namespace. Thus, we can allocate all in once and get rid of all the code needed to allocate and free these ipc_ids separately. Signed-off-by: Pierre Peiffer Acked-by: Cedric Le Goater Cc: Pavel Emelyanov Cc: Nadia Derbey Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

ipc: uninline some code from util.h

2008-02-08T17:22:25Z

ipc_lock_check_down(), ipc_lock_check() and ipcget() seem too large to be inline. Besides, they give no optimization being inline as they perform calls inside in any case. Moving them into ipc/util.c saves 500 bytes of vmlinux and shortens IPC internal API. $ ./scripts/bloat-o-meter vmlinux-orig vmlinux add/remove: 3/2 grow/shrink: 0/10 up/down: 490/-989 (-499) function old new delta ipcget - 392 +392 ipc_lock_check_down - 49 +49 ipc_lock_check - 49 +49 sys_semget 119 105 -14 sys_shmget 108 86 -22 sys_msgget 100 78 -22 do_msgsnd 665 631 -34 do_msgrcv 680 644 -36 do_shmat 771 733 -38 sys_msgctl 1302 1229 -73 ipcget_new 80 - -80 sys_semtimedop 1534 1452 -82 sys_semctl 2034 1922 -112 sys_shmctl 1919 1765 -154 ipcget_public 322 - -322 The ipcget() growth is the result of gcc inlining of currently static ipcget_new/_public. Signed-off-by: Pavel Emelyanov Cc: Nadia Derbey Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds