4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 only,
8 * as published by the Free Software Foundation.
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * General Public License version 2 for more details (a copy is included
14 * in the LICENSE file that accompanied this code).
16 * You should have received a copy of the GNU General Public License
17 * version 2 along with this program; if not, write to the
18 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
19 * Boston, MA 021110-1307, USA
23 /* Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved.
24 * Copyright (c) 2012, Intel Corporation.
27 * This file is part of Lustre, http://www.lustre.org/
28 * Lustre is a trademark of Sun Microsystems, Inc.
30 * Author: liang@whamcloud.com
33 #define DEBUG_SUBSYSTEM S_LNET
35 #include <libcfs/libcfs.h>
37 /** destroy cpu-partition lock, see libcfs_private.h for more detail */
39 cfs_percpt_lock_free(struct cfs_percpt_lock *pcl)
41 LASSERT(pcl->pcl_locks != NULL);
42 LASSERT(!pcl->pcl_locked);
44 cfs_percpt_free(pcl->pcl_locks);
45 LIBCFS_FREE(pcl, sizeof(*pcl));
47 EXPORT_SYMBOL(cfs_percpt_lock_free);
50 * create cpu-partition lock, see libcfs_private.h for more detail.
52 * cpu-partition lock is designed for large-scale SMP system, so we need to
53 * reduce cacheline conflict as possible as we can, that's the
54 * reason we always allocate cacheline-aligned memory block.
56 struct cfs_percpt_lock *
57 cfs_percpt_lock_alloc(struct cfs_cpt_table *cptab)
59 struct cfs_percpt_lock *pcl;
63 /* NB: cptab can be NULL, pcl will be for HW CPUs on that case */
64 LIBCFS_ALLOC(pcl, sizeof(*pcl));
68 pcl->pcl_cptab = cptab;
69 pcl->pcl_locks = cfs_percpt_alloc(cptab, sizeof(*lock));
70 if (pcl->pcl_locks == NULL) {
71 LIBCFS_FREE(pcl, sizeof(*pcl));
75 cfs_percpt_for_each(lock, i, pcl->pcl_locks)
80 EXPORT_SYMBOL(cfs_percpt_lock_alloc);
83 * lock a CPU partition
85 * \a index != CFS_PERCPT_LOCK_EX
86 * hold private lock indexed by \a index
88 * \a index == CFS_PERCPT_LOCK_EX
89 * exclusively lock @pcl and nobody can take private lock
92 cfs_percpt_lock(struct cfs_percpt_lock *pcl, int index)
93 __acquires(pcl->pcl_locks)
95 int ncpt = cfs_cpt_number(pcl->pcl_cptab);
98 LASSERT(index >= CFS_PERCPT_LOCK_EX && index < ncpt);
102 } else { /* serialize with exclusive lock */
103 while (pcl->pcl_locked)
107 if (likely(index != CFS_PERCPT_LOCK_EX)) {
108 spin_lock(pcl->pcl_locks[index]);
112 /* exclusive lock request */
113 for (i = 0; i < ncpt; i++) {
114 spin_lock(pcl->pcl_locks[i]);
116 LASSERT(!pcl->pcl_locked);
117 /* nobody should take private lock after this
118 * so I wouldn't starve for too long time */
123 EXPORT_SYMBOL(cfs_percpt_lock);
125 /** unlock a CPU partition */
127 cfs_percpt_unlock(struct cfs_percpt_lock *pcl, int index)
128 __releases(pcl->pcl_locks)
130 int ncpt = cfs_cpt_number(pcl->pcl_cptab);
133 index = ncpt == 1 ? 0 : index;
135 if (likely(index != CFS_PERCPT_LOCK_EX)) {
136 spin_unlock(pcl->pcl_locks[index]);
140 for (i = ncpt - 1; i >= 0; i--) {
142 LASSERT(pcl->pcl_locked);
145 spin_unlock(pcl->pcl_locks[i]);
148 EXPORT_SYMBOL(cfs_percpt_unlock);
150 /** free cpu-partition refcount */
152 cfs_percpt_atomic_free(atomic_t **refs)
154 cfs_percpt_free(refs);
156 EXPORT_SYMBOL(cfs_percpt_atomic_free);
158 /** allocate cpu-partition refcount with initial value @init_val */
160 cfs_percpt_atomic_alloc(struct cfs_cpt_table *cptab, int init_val)
166 refs = cfs_percpt_alloc(cptab, sizeof(*ref));
170 cfs_percpt_for_each(ref, i, refs)
171 atomic_set(ref, init_val);
174 EXPORT_SYMBOL(cfs_percpt_atomic_alloc);
176 /** return sum of cpu-partition refs */
178 cfs_percpt_atomic_summary(atomic_t **refs)
184 cfs_percpt_for_each(ref, i, refs)
185 val += atomic_read(ref);
189 EXPORT_SYMBOL(cfs_percpt_atomic_summary);