[PATCH 35/47] staging/lustre: replace semaphores with mutexes
From: Oleg Drokin
Date: Sun Apr 27 2014 - 13:12:17 EST
From: Dmitry Eremin <dmitry.eremin@xxxxxxxxx>
It's just optimization. The mutex subsystem is slightly faster
and has better scalability for contended workloads.
Remove the lustre_lock and it's accessor functions l_lock(),
l_unlock(), l_lock_init(), and l_has_lock() since they have
not been used by the code since Lustre 1.6.
Signed-off-by: Dmitry Eremin <dmitry.eremin@xxxxxxxxx>
Reviewed-on: http://review.whamcloud.com/9294
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-4588
Reviewed-by: Andreas Dilger <andreas.dilger@xxxxxxxxx>
Reviewed-by: John L. Hammond <john.hammond@xxxxxxxxx>
Reviewed-by: James Simmons <uja.ornl@xxxxxxxxx>
Reviewed-by: Alex Zhuravlev <alexey.zhuravlev@xxxxxxxxx>
Signed-off-by: Oleg Drokin <oleg.drokin@xxxxxxxxx>
---
drivers/staging/lustre/lustre/include/lustre_lib.h | 13 -------------
drivers/staging/lustre/lustre/include/obd.h | 2 +-
drivers/staging/lustre/lustre/ldlm/ldlm_lib.c | 2 +-
drivers/staging/lustre/lustre/libcfs/linux/linux-cpu.c | 16 ++++++++--------
drivers/staging/lustre/lustre/mgc/mgc_request.c | 8 ++++----
5 files changed, 14 insertions(+), 27 deletions(-)
diff --git a/drivers/staging/lustre/lustre/include/lustre_lib.h b/drivers/staging/lustre/lustre/include/lustre_lib.h
index 0368ca6..bdc9812 100644
--- a/drivers/staging/lustre/lustre/include/lustre_lib.h
+++ b/drivers/staging/lustre/lustre/include/lustre_lib.h
@@ -94,19 +94,6 @@ struct obd_client_handle {
void statfs_pack(struct obd_statfs *osfs, struct kstatfs *sfs);
void statfs_unpack(struct kstatfs *sfs, struct obd_statfs *osfs);
-/* l_lock.c */
-struct lustre_lock {
- int l_depth;
- struct task_struct *l_owner;
- struct semaphore l_sem;
- spinlock_t l_spin;
-};
-
-void l_lock_init(struct lustre_lock *);
-void l_lock(struct lustre_lock *);
-void l_unlock(struct lustre_lock *);
-int l_has_lock(struct lustre_lock *);
-
/*
* For md echo client
*/
diff --git a/drivers/staging/lustre/lustre/include/obd.h b/drivers/staging/lustre/lustre/include/obd.h
index 7ed5fcd..d5c4613 100644
--- a/drivers/staging/lustre/lustre/include/obd.h
+++ b/drivers/staging/lustre/lustre/include/obd.h
@@ -406,7 +406,7 @@ struct client_obd {
struct mdc_rpc_lock *cl_close_lock;
/* mgc datastruct */
- struct semaphore cl_mgc_sem;
+ struct mutex cl_mgc_mutex;
struct local_oid_storage *cl_mgc_los;
struct dt_object *cl_mgc_configs_dir;
atomic_t cl_mgc_refcount;
diff --git a/drivers/staging/lustre/lustre/ldlm/ldlm_lib.c b/drivers/staging/lustre/lustre/ldlm/ldlm_lib.c
index 42f5f1e..8bb5915 100644
--- a/drivers/staging/lustre/lustre/ldlm/ldlm_lib.c
+++ b/drivers/staging/lustre/lustre/ldlm/ldlm_lib.c
@@ -325,7 +325,7 @@ int client_obd_setup(struct obd_device *obddev, struct lustre_cfg *lcfg)
}
init_rwsem(&cli->cl_sem);
- sema_init(&cli->cl_mgc_sem, 1);
+ mutex_init(&cli->cl_mgc_mutex);
cli->cl_conn_count = 0;
memcpy(server_uuid.uuid, lustre_cfg_buf(lcfg, 2),
min_t(unsigned int, LUSTRE_CFG_BUFLEN(lcfg, 2),
diff --git a/drivers/staging/lustre/lustre/libcfs/linux/linux-cpu.c b/drivers/staging/lustre/lustre/libcfs/linux/linux-cpu.c
index d169374..fc21210 100644
--- a/drivers/staging/lustre/lustre/libcfs/linux/linux-cpu.c
+++ b/drivers/staging/lustre/lustre/libcfs/linux/linux-cpu.c
@@ -71,7 +71,7 @@ struct cfs_cpt_data {
/* reserved for hotplug */
unsigned long cpt_version;
/* mutex to protect cpt_cpumask */
- struct semaphore cpt_mutex;
+ struct mutex cpt_mutex;
/* scratch buffer for set/unset_node */
cpumask_t *cpt_cpumask;
};
@@ -420,14 +420,14 @@ cfs_cpt_set_node(struct cfs_cpt_table *cptab, int cpt, int node)
return 0;
}
- down(&cpt_data.cpt_mutex);
+ mutex_lock(&cpt_data.cpt_mutex);
mask = cpt_data.cpt_cpumask;
cfs_node_to_cpumask(node, mask);
rc = cfs_cpt_set_cpumask(cptab, cpt, mask);
- up(&cpt_data.cpt_mutex);
+ mutex_unlock(&cpt_data.cpt_mutex);
return rc;
}
@@ -444,14 +444,14 @@ cfs_cpt_unset_node(struct cfs_cpt_table *cptab, int cpt, int node)
return;
}
- down(&cpt_data.cpt_mutex);
+ mutex_lock(&cpt_data.cpt_mutex);
mask = cpt_data.cpt_cpumask;
cfs_node_to_cpumask(node, mask);
cfs_cpt_unset_cpumask(cptab, cpt, mask);
- up(&cpt_data.cpt_mutex);
+ mutex_unlock(&cpt_data.cpt_mutex);
}
EXPORT_SYMBOL(cfs_cpt_unset_node);
@@ -969,11 +969,11 @@ cfs_cpu_notify(struct notifier_block *self, unsigned long action, void *hcpu)
break;
}
- down(&cpt_data.cpt_mutex);
+ mutex_lock(&cpt_data.cpt_mutex);
/* if all HTs in a core are offline, it may break affinity */
cfs_cpu_ht_siblings(cpu, cpt_data.cpt_cpumask);
warn = any_online_cpu(*cpt_data.cpt_cpumask) >= nr_cpu_ids;
- up(&cpt_data.cpt_mutex);
+ mutex_unlock(&cpt_data.cpt_mutex);
CDEBUG(warn ? D_WARNING : D_INFO,
"Lustre: can't support CPU plug-out well now, "
"performance and stability could be impacted "
@@ -1017,7 +1017,7 @@ cfs_cpu_init(void)
}
spin_lock_init(&cpt_data.cpt_lock);
- sema_init(&cpt_data.cpt_mutex, 1);
+ mutex_init(&cpt_data.cpt_mutex);
#ifdef CONFIG_HOTPLUG_CPU
register_hotcpu_notifier(&cfs_cpu_notifier);
diff --git a/drivers/staging/lustre/lustre/mgc/mgc_request.c b/drivers/staging/lustre/lustre/mgc/mgc_request.c
index de9fb14..a806aef 100644
--- a/drivers/staging/lustre/lustre/mgc/mgc_request.c
+++ b/drivers/staging/lustre/lustre/mgc/mgc_request.c
@@ -672,8 +672,8 @@ static int mgc_fs_setup(struct obd_device *obd, struct super_block *sb)
if (env == NULL)
return -ENOMEM;
- /* The mgc fs exclusion sem. Only one fs can be setup at a time. */
- down(&cli->cl_mgc_sem);
+ /* The mgc fs exclusion mutex. Only one fs can be setup at a time. */
+ mutex_lock(&cli->cl_mgc_mutex);
cfs_cleanup_group_info();
@@ -727,7 +727,7 @@ out_los:
if (rc < 0) {
local_oid_storage_fini(env, cli->cl_mgc_los);
cli->cl_mgc_los = NULL;
- up(&cli->cl_mgc_sem);
+ mutex_unlock(&cli->cl_mgc_mutex);
}
out_env:
lu_env_fini(env);
@@ -759,7 +759,7 @@ static int mgc_fs_cleanup(struct obd_device *obd)
unlock:
class_decref(obd, "mgc_fs", obd);
- up(&cli->cl_mgc_sem);
+ mutex_unlock(&cli->cl_mgc_mutex);
return 0;
}
--
1.8.5.3
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