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fs: dlm: use spin lock instead of mutex

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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: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
This commit is contained in:
Alexander Aring 2022-10-27 16:45:19 -04:00 committed by David Teigland
parent a4c0352bb1
commit 92e9573330
3 changed files with 6 additions and 6 deletions
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8
fs/dlm/ast.c
View File

@ -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;

2
fs/dlm/dlm_internal.h
View File

@ -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];

2
fs/dlm/lock.c
View File

@ -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);