[PATCH 05/08] This patch makes 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 --- ipc/util.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) Index: linux-2.6.24-mm1/ipc/util.c =================================================================== --- linux-2.6.24-mm1.orig/ipc/util.c 2008-02-08 08:15:35.000000000 +0100 +++ linux-2.6.24-mm1/ipc/util.c 2008-02-08 14:14:03.000000000 +0100 @@ -58,6 +58,14 @@ atomic_t nr_ipc_ns = ATOMIC_INIT(1); #ifdef CONFIG_MEMORY_HOTPLUG +static void ipc_memory_notifier(struct work_struct *work) +{ + ipcns_notify(IPCNS_MEMCHANGED); +} + +static DECLARE_WORK(ipc_memory_wq, ipc_memory_notifier); + + static int ipc_memory_callback(struct notifier_block *self, unsigned long action, void *arg) { @@ -67,8 +75,13 @@ static int ipc_memory_callback(struct no /* * This is done by invoking the ipcns notifier chain with the * IPC_MEMCHANGED event. + * In order not to keep the lock on the hotplug memory chain + * for too long, queue a work item that will, when waken up, + * activate the ipcns notification chain. + * No need to keep several ipc work items on the queue. */ - ipcns_notify(IPCNS_MEMCHANGED); + if (!work_pending(&ipc_memory_wq)) + schedule_work(&ipc_memory_wq); break; case MEM_GOING_ONLINE: case MEM_GOING_OFFLINE: -- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/