From e8216dee838c09776680a6f1a2e54d81f3cdfa14 Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Mon, 25 Sep 2006 23:33:11 -0700 Subject: [PATCH] [PATCH] s390: fix cmm kernel thread handling Convert cmm's usage of kernel_thread to kthread_run. Also create the cmmthread at module load time, so it is possible to check if creation of the thread fails. In addition the cmmthread now gets terminated when the module gets unloaded instead of leaving a stale kernel thread. Also check the return values of other registration functions at module load and handle their return values appropriately. Cc: Martin Schwidefsky Signed-off-by: Heiko Carstens Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/s390/mm/cmm.c | 54 ++++++++++++++++++++++++++++++---------------- 1 file changed, 35 insertions(+), 19 deletions(-) diff --git a/arch/s390/mm/cmm.c b/arch/s390/mm/cmm.c index f2e00df99ba..607f50ead1f 100644 --- a/arch/s390/mm/cmm.c +++ b/arch/s390/mm/cmm.c @@ -16,6 +16,7 @@ #include #include #include +#include #include #include @@ -46,8 +47,7 @@ static struct cmm_page_array *cmm_page_list; static struct cmm_page_array *cmm_timed_page_list; static DEFINE_SPINLOCK(cmm_lock); -static unsigned long cmm_thread_active; -static struct work_struct cmm_thread_starter; +static struct task_struct *cmm_thread_ptr; static wait_queue_head_t cmm_thread_wait; static struct timer_list cmm_timer; @@ -143,14 +143,12 @@ cmm_thread(void *dummy) { int rc; - daemonize("cmmthread"); while (1) { rc = wait_event_interruptible(cmm_thread_wait, (cmm_pages != cmm_pages_target || - cmm_timed_pages != cmm_timed_pages_target)); - if (rc == -ERESTARTSYS) { - /* Got kill signal. End thread. */ - clear_bit(0, &cmm_thread_active); + cmm_timed_pages != cmm_timed_pages_target || + kthread_should_stop())); + if (kthread_should_stop() || rc == -ERESTARTSYS) { cmm_pages_target = cmm_pages; cmm_timed_pages_target = cmm_timed_pages; break; @@ -175,17 +173,9 @@ cmm_thread(void *dummy) return 0; } -static void -cmm_start_thread(void) -{ - kernel_thread(cmm_thread, NULL, 0); -} - static void cmm_kick_thread(void) { - if (!test_and_set_bit(0, &cmm_thread_active)) - schedule_work(&cmm_thread_starter); wake_up(&cmm_thread_wait); } @@ -429,22 +419,48 @@ struct ctl_table_header *cmm_sysctl_header; static int cmm_init (void) { + int rc = -ENOMEM; + #ifdef CONFIG_CMM_PROC cmm_sysctl_header = register_sysctl_table(cmm_dir_table, 1); + if (!cmm_sysctl_header) + goto out; #endif #ifdef CONFIG_CMM_IUCV - smsg_register_callback(SMSG_PREFIX, cmm_smsg_target); + rc = smsg_register_callback(SMSG_PREFIX, cmm_smsg_target); + if (rc < 0) + goto out_smsg; #endif - register_oom_notifier(&cmm_oom_nb); - INIT_WORK(&cmm_thread_starter, (void *) cmm_start_thread, NULL); + rc = register_oom_notifier(&cmm_oom_nb); + if (rc < 0) + goto out_oom_notify; init_waitqueue_head(&cmm_thread_wait); init_timer(&cmm_timer); - return 0; + cmm_thread_ptr = kthread_run(cmm_thread, NULL, "cmmthread"); + rc = IS_ERR(cmm_thread_ptr) ? PTR_ERR(cmm_thread_ptr) : 0; + if (!rc) + goto out; + /* + * kthread_create failed. undo all the stuff from above again. + */ + unregister_oom_notifier(&cmm_oom_nb); + +out_oom_notify: +#ifdef CONFIG_CMM_IUCV + smsg_unregister_callback(SMSG_PREFIX, cmm_smsg_target); +out_smsg: +#endif +#ifdef CONFIG_CMM_PROC + unregister_sysctl_table(cmm_sysctl_header); +#endif +out: + return rc; } static void cmm_exit(void) { + kthread_stop(cmm_thread_ptr); unregister_oom_notifier(&cmm_oom_nb); cmm_free_pages(cmm_pages, &cmm_pages, &cmm_page_list); cmm_free_pages(cmm_timed_pages, &cmm_timed_pages, &cmm_timed_page_list); -- 2.41.1