Commit 92e95733 authored by Alexander Aring's avatar Alexander Aring Committed by David Teigland
Browse files

fs: dlm: use spin lock instead of mutex 



There is no need to use a mutex in those hot path sections. We change it
to spin lock to serve callbacks more faster by not allowing schedule.
The locked sections will not be locked for a long time.

Signed-off-by: default avatarAlexander Aring <aahringo@redhat.com>
Signed-off-by: default avatarDavid Teigland <teigland@redhat.com>
parent a4c0352b

fs/dlm/ast.c

+4 −4
Original line number Diff line number Diff line
@@ -190,7 +190,7 @@ void dlm_add_cb(struct dlm_lkb *lkb, uint32_t flags, int mode, int status, 
		return;

	}



	mutex_lock(&lkb->lkb_cb_mutex);

	spin_lock(&lkb->lkb_cb_lock);

	prev_seq = lkb->lkb_callbacks[0].seq;



	rv = dlm_add_lkb_callback(lkb, flags, mode, status, sbflags, new_seq);
@@ -209,7 +209,7 @@ void dlm_add_cb(struct dlm_lkb *lkb, uint32_t flags, int mode, int status, 
		spin_unlock(&ls->ls_cb_lock);

	}

 out:

	mutex_unlock(&lkb->lkb_cb_mutex);

	spin_unlock(&lkb->lkb_cb_lock);

}



void dlm_callback_work(struct work_struct *work)
@@ -223,7 +223,7 @@ void dlm_callback_work(struct work_struct *work) 


	memset(&callbacks, 0, sizeof(callbacks));



	mutex_lock(&lkb->lkb_cb_mutex);

	spin_lock(&lkb->lkb_cb_lock);

	if (!lkb->lkb_callbacks[0].seq) {

		/* no callback work exists, shouldn't happen */

		log_error(ls, "dlm_callback_work %x no work", lkb->lkb_id);
@@ -244,7 +244,7 @@ void dlm_callback_work(struct work_struct *work) 
		dlm_print_lkb(lkb);

		dlm_dump_lkb_callbacks(lkb);

	}

	mutex_unlock(&lkb->lkb_cb_mutex);

	spin_unlock(&lkb->lkb_cb_lock);



	castfn = lkb->lkb_astfn;

	bastfn = lkb->lkb_bastfn;

fs/dlm/dlm_internal.h

+1 −1
Original line number Diff line number Diff line
@@ -268,7 +268,7 @@ struct dlm_lkb { 
	unsigned long		lkb_timeout_cs;

#endif



	struct mutex		lkb_cb_mutex;

	spinlock_t		lkb_cb_lock;

	struct work_struct	lkb_cb_work;

	struct list_head	lkb_cb_list; /* for ls_cb_delay or proc->asts */

	struct dlm_callback	lkb_callbacks[DLM_CALLBACKS_SIZE];

fs/dlm/lock.c

+1 −1
Original line number Diff line number Diff line
@@ -1218,7 +1218,7 @@ static int _create_lkb(struct dlm_ls *ls, struct dlm_lkb **lkb_ret, 
	INIT_LIST_HEAD(&lkb->lkb_time_list);

#endif

	INIT_LIST_HEAD(&lkb->lkb_cb_list);

	mutex_init(&lkb->lkb_cb_mutex);

	spin_lock_init(&lkb->lkb_cb_lock);

	INIT_WORK(&lkb->lkb_cb_work, dlm_callback_work);



	idr_preload(GFP_NOFS);