From 424450c1dbe72b6e2637e91108417d7d9580c4c3 Mon Sep 17 00:00:00 2001 From: Nadia Derbey Date: Tue, 29 Apr 2008 01:00:43 -0700 Subject: ipc: invoke the ipcns notifier chain as a work item 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/util.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) (limited to 'ipc') diff --git a/ipc/util.c b/ipc/util.c index 2d545d7144a7..7a5d5e393c4b 100644 --- a/ipc/util.c +++ b/ipc/util.c @@ -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 notifier_block *self, /* * 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: -- cgit v1.2.3