From 8b31719041662bae54d9acbef4e8c907756cdb6c Mon Sep 17 00:00:00 2001 From: Rabin Vincent Date: Thu, 9 Sep 2010 10:48:21 +0530 Subject: lowmemorykiller: don't unregister notifier from atomic context The lowmemorykiller registers an atomic notifier for notfication of when the task is freed. From this atomic notifier callback, it removes the atomic notifier via task_free_unregister(). This is incorrect because atomic_notifier_chain_unregister() calls syncronize_rcu(), which can sleep, which shouldn't be done from an atomic notifier. Fix this by registering the notifier during init, and only unregister it if the lowmemorykiller is unloaded. Change-Id: Ie9cf2f23d31c78e1fe1b9dd2e11af5267832ee94 Signed-off-by: Rabin Vincent Signed-off-by: Christian Bejram Reviewed-on: http://git-master/r/13943 Reviewed-by: Ching Kuang (Roger) Hsieh Tested-by: Ching Kuang (Roger) Hsieh Reviewed-by: Bharat Nihalani --- drivers/staging/android/lowmemorykiller.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/drivers/staging/android/lowmemorykiller.c b/drivers/staging/android/lowmemorykiller.c index 39d5e6502b21..37ed0f8c432c 100644 --- a/drivers/staging/android/lowmemorykiller.c +++ b/drivers/staging/android/lowmemorykiller.c @@ -71,10 +71,10 @@ static int task_notify_func(struct notifier_block *self, unsigned long val, void *data) { struct task_struct *task = data; - if (task == lowmem_deathpending) { + + if (task == lowmem_deathpending) lowmem_deathpending = NULL; - task_free_unregister(&task_nb); - } + return NOTIFY_OK; } @@ -168,7 +168,6 @@ static int lowmem_shrink(int nr_to_scan, gfp_t gfp_mask) selected->pid, selected->comm, selected_oom_adj, selected_tasksize); lowmem_deathpending = selected; - task_free_register(&task_nb); force_sig(SIGKILL, selected); rem -= selected_tasksize; } @@ -185,6 +184,7 @@ static struct shrinker lowmem_shrinker = { static int __init lowmem_init(void) { + task_free_register(&task_nb); register_shrinker(&lowmem_shrinker); return 0; } @@ -192,6 +192,7 @@ static int __init lowmem_init(void) static void __exit lowmem_exit(void) { unregister_shrinker(&lowmem_shrinker); + task_free_unregister(&task_nb); } module_param_named(cost, lowmem_shrinker.seeks, int, S_IRUGO | S_IWUSR); -- cgit v1.2.3