From 164d88abd7608e869b7617d5ff8893344fdda759 Mon Sep 17 00:00:00 2001 From: Alexander Aring Date: Tue, 2 Nov 2021 15:17:17 -0400 Subject: fs: dlm: requestqueue busy wait to event based wait This patch changes the requestqueue busy waiting algorithm to use atomic counter values and wait_event() to wait until the requestqueue is empty. It will slightly reduce the number of holding ls_requestqueue_mutex mutex. Signed-off-by: Alexander Aring Signed-off-by: David Teigland --- fs/dlm/dlm_internal.h | 2 ++ fs/dlm/lockspace.c | 2 ++ fs/dlm/requestqueue.c | 15 +++++++-------- 3 files changed, 11 insertions(+), 8 deletions(-) (limited to 'fs/dlm') diff --git a/fs/dlm/dlm_internal.h b/fs/dlm/dlm_internal.h index 44a5c67b5213..fd1c7a8c4485 100644 --- a/fs/dlm/dlm_internal.h +++ b/fs/dlm/dlm_internal.h @@ -626,6 +626,8 @@ struct dlm_ls { struct rw_semaphore ls_in_recovery; /* block local requests */ struct rw_semaphore ls_recv_active; /* block dlm_recv */ struct list_head ls_requestqueue;/* queue remote requests */ + atomic_t ls_requestqueue_cnt; + wait_queue_head_t ls_requestqueue_wait; struct mutex ls_requestqueue_mutex; struct dlm_rcom *ls_recover_buf; int ls_recover_nodeid; /* for debugging */ diff --git a/fs/dlm/lockspace.c b/fs/dlm/lockspace.c index b90566502a81..4e4181304ca1 100644 --- a/fs/dlm/lockspace.c +++ b/fs/dlm/lockspace.c @@ -564,6 +564,8 @@ static int new_lockspace(const char *name, const char *cluster, init_rwsem(&ls->ls_in_recovery); init_rwsem(&ls->ls_recv_active); INIT_LIST_HEAD(&ls->ls_requestqueue); + atomic_set(&ls->ls_requestqueue_cnt, 0); + init_waitqueue_head(&ls->ls_requestqueue_wait); mutex_init(&ls->ls_requestqueue_mutex); mutex_init(&ls->ls_clear_proc_locks); diff --git a/fs/dlm/requestqueue.c b/fs/dlm/requestqueue.c index e89e0ff8bfa3..d0cf68570dcf 100644 --- a/fs/dlm/requestqueue.c +++ b/fs/dlm/requestqueue.c @@ -44,6 +44,7 @@ void dlm_add_requestqueue(struct dlm_ls *ls, int nodeid, struct dlm_message *ms) e->nodeid = nodeid; memcpy(&e->request, ms, ms->m_header.h_length); + atomic_inc(&ls->ls_requestqueue_cnt); mutex_lock(&ls->ls_requestqueue_mutex); list_add_tail(&e->list, &ls->ls_requestqueue); mutex_unlock(&ls->ls_requestqueue_mutex); @@ -89,6 +90,8 @@ int dlm_process_requestqueue(struct dlm_ls *ls) mutex_lock(&ls->ls_requestqueue_mutex); list_del(&e->list); + if (atomic_dec_and_test(&ls->ls_requestqueue_cnt)) + wake_up(&ls->ls_requestqueue_wait); kfree(e); if (dlm_locking_stopped(ls)) { @@ -115,14 +118,8 @@ int dlm_process_requestqueue(struct dlm_ls *ls) void dlm_wait_requestqueue(struct dlm_ls *ls) { - for (;;) { - mutex_lock(&ls->ls_requestqueue_mutex); - if (list_empty(&ls->ls_requestqueue)) - break; - mutex_unlock(&ls->ls_requestqueue_mutex); - schedule(); - } - mutex_unlock(&ls->ls_requestqueue_mutex); + wait_event(ls->ls_requestqueue_wait, + atomic_read(&ls->ls_requestqueue_cnt) == 0); } static int purge_request(struct dlm_ls *ls, struct dlm_message *ms, int nodeid) @@ -161,6 +158,8 @@ void dlm_purge_requestqueue(struct dlm_ls *ls) if (purge_request(ls, ms, e->nodeid)) { list_del(&e->list); + if (atomic_dec_and_test(&ls->ls_requestqueue_cnt)) + wake_up(&ls->ls_requestqueue_wait); kfree(e); } } -- cgit v1.2.3