From be3c64da248b1ada2bbcfc3855f07536d8087acb Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Fri, 2 Mar 2018 10:31:25 +1100 Subject: [PATCH] staging: lustre: ptlrpc: use workqueue for pinger lustre has a "Pinger" kthread which periodically pings peers to ensure all hosts are functioning. This can more easily be done using a work queue. As maintaining contact with other peers is import for keeping the filesystem running, and as the filesystem might be involved in freeing memory, it is safest to have a separate WQ_MEM_RECLAIM workqueue. The SVC_EVENT functionality to wake up the thread can be replaced with mod_delayed_work(). Also use round_jiffies_up_relative() rather than setting a minimum of 1 second delay. The PING_INTERVAL is measured in seconds so this meets the need is allow the workqueue to keep wakeups synchronized. Signed-off-by: NeilBrown Signed-off-by: Greg Kroah-Hartman --- drivers/staging/lustre/lustre/ptlrpc/pinger.c | 81 ++++++------------- 1 file changed, 24 insertions(+), 57 deletions(-) diff --git a/drivers/staging/lustre/lustre/ptlrpc/pinger.c b/drivers/staging/lustre/lustre/ptlrpc/pinger.c index b5f3cfee8e75..0775b7a048bb 100644 --- a/drivers/staging/lustre/lustre/ptlrpc/pinger.c +++ b/drivers/staging/lustre/lustre/ptlrpc/pinger.c @@ -217,21 +217,18 @@ static void ptlrpc_pinger_process_import(struct obd_import *imp, } } -static int ptlrpc_pinger_main(void *arg) -{ - struct ptlrpc_thread *thread = arg; - - /* Record that the thread is running */ - thread_set_flags(thread, SVC_RUNNING); - wake_up(&thread->t_ctl_waitq); +static struct workqueue_struct *pinger_wq; +static void ptlrpc_pinger_main(struct work_struct *ws); +static DECLARE_DELAYED_WORK(ping_work, ptlrpc_pinger_main); - /* And now, loop forever, pinging as needed. */ - while (1) { - unsigned long this_ping = cfs_time_current(); - long time_to_next_wake; - struct timeout_item *item; - struct obd_import *imp; +static void ptlrpc_pinger_main(struct work_struct *ws) +{ + unsigned long this_ping = cfs_time_current(); + long time_to_next_wake; + struct timeout_item *item; + struct obd_import *imp; + do { mutex_lock(&pinger_mutex); list_for_each_entry(item, &timeout_list, ti_chain) { item->ti_cb(item, item->ti_cb_data); @@ -260,50 +257,24 @@ static int ptlrpc_pinger_main(void *arg) time_to_next_wake, cfs_time_add(this_ping, PING_INTERVAL * HZ)); - if (time_to_next_wake > 0) { - wait_event_idle_timeout(thread->t_ctl_waitq, - thread_is_stopping(thread) || - thread_is_event(thread), - max_t(long, time_to_next_wake, HZ)); - if (thread_test_and_clear_flags(thread, SVC_STOPPING)) - break; - /* woken after adding import to reset timer */ - thread_test_and_clear_flags(thread, SVC_EVENT); - } - } + } while (time_to_next_wake <= 0); - thread_set_flags(thread, SVC_STOPPED); - wake_up(&thread->t_ctl_waitq); - - CDEBUG(D_NET, "pinger thread exiting, process %d\n", current_pid()); - return 0; + queue_delayed_work(pinger_wq, &ping_work, + round_jiffies_up_relative(time_to_next_wake)); } -static struct ptlrpc_thread pinger_thread; - int ptlrpc_start_pinger(void) { - struct task_struct *task; - int rc; - - if (!thread_is_init(&pinger_thread) && - !thread_is_stopped(&pinger_thread)) + if (pinger_wq) return -EALREADY; - init_waitqueue_head(&pinger_thread.t_ctl_waitq); - - strcpy(pinger_thread.t_name, "ll_ping"); - - task = kthread_run(ptlrpc_pinger_main, &pinger_thread, - pinger_thread.t_name); - if (IS_ERR(task)) { - rc = PTR_ERR(task); - CERROR("cannot start pinger thread: rc = %d\n", rc); - return rc; + pinger_wq = alloc_workqueue("ptlrpc_pinger", WQ_MEM_RECLAIM, 1); + if (!pinger_wq) { + CERROR("cannot start pinger workqueue\n"); + return -ENOMEM; } - wait_event_idle(pinger_thread.t_ctl_waitq, - thread_is_running(&pinger_thread)); + queue_delayed_work(pinger_wq, &ping_work, 0); return 0; } @@ -313,16 +284,13 @@ int ptlrpc_stop_pinger(void) { int rc = 0; - if (thread_is_init(&pinger_thread) || - thread_is_stopped(&pinger_thread)) + if (!pinger_wq) return -EALREADY; ptlrpc_pinger_remove_timeouts(); - thread_set_flags(&pinger_thread, SVC_STOPPING); - wake_up(&pinger_thread.t_ctl_waitq); - - wait_event_idle(pinger_thread.t_ctl_waitq, - thread_is_stopped(&pinger_thread)); + cancel_delayed_work_sync(&ping_work); + destroy_workqueue(pinger_wq); + pinger_wq = NULL; return rc; } @@ -505,6 +473,5 @@ static int ptlrpc_pinger_remove_timeouts(void) void ptlrpc_pinger_wake_up(void) { - thread_add_flags(&pinger_thread, SVC_EVENT); - wake_up(&pinger_thread.t_ctl_waitq); + mod_delayed_work(pinger_wq, &ping_work, 0); } -- 2.30.2