29 Apr, 2008

3 commits

  • The enhancement as asked for by Yasunori: if msgmni is set to a negative
    value, register it back into the ipcns notifier chain.

    A new interface has been added to the notification mechanism:
    notifier_chain_cond_register() registers a notifier block only if not already
    registered. With that new interface we avoid taking care of the states
    changes in procfs.

    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

    Nadia Derbey
     
  • Introduce a notification mechanism that aims at recomputing msgmni each time
    an ipc namespace is created or removed.

    The ipc namespace notifier chain already defined for memory hotplug management
    is used for that purpose too.

    Each time a new ipc namespace is allocated or an existing ipc namespace is
    removed, the ipcns notifier chain is notified. The callback routine for each
    registered ipc namespace is then activated in order to recompute msgmni for
    that 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

    Nadia Derbey
     
  • 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

    Nadia Derbey