[PATCH v3 06/14] ipc: Remove redundant rcu_read_lock/unlock() in spin_lock
pengdonglin <[email protected]>
| Newsgroups | gmane.linux.kernel.aio.general,gmane.linux.kernel,gmane.linux.nfs,gmane.linux.file-systems,gmane.linux.kernel.lsm,gmane.linux.network,gmane.comp.freedesktop.xorg.drivers.intel,gmane.linux.kernel.wireless.general,gmane.linux.acpi.devel,gmane.linux.kernel.cgroups |
|---|---|
| Message-ID | <[email protected]> |
From: pengdonglin <[email protected]> Since commit a8bb74acd8efe ("rcu: Consolidate RCU-sched update-side function definitions") there is no difference between rcu_read_lock(), rcu_read_lock_bh() and rcu_read_lock_sched() in terms of RCU read section and the relevant grace period. That means that spin_lock(), which implies rcu_read_lock_sched(), also implies rcu_read_lock(). There is no need no explicitly start a RCU read section if one has already been started implicitly by spin_lock(). Simplify the code and remove the inner rcu_read_lock() invocation. Signed-off-by: pengdonglin <[email protected]> Signed-off-by: pengdonglin <[email protected]> --- ipc/msg.c | 1 - ipc/sem.c | 1 - ipc/shm.c | 1 - ipc/util.c | 2 -- 4 files changed, 5 deletions(-) diff --git a/ipc/msg.c b/ipc/msg.c index ee6af4fe52bf..1e579b57023f 100644 --- a/ipc/msg.c +++ b/ipc/msg.c @@ -179,7 +179,6 @@ static int newque(struct ipc_namespace *ns, struct ipc_params *params) } ipc_unlock_object(&msq->q_perm); - rcu_read_unlock(); return msq->q_perm.id; } diff --git a/ipc/sem.c b/ipc/sem.c index a39cdc7bf88f..38ad57b2b558 100644 --- a/ipc/sem.c +++ b/ipc/sem.c @@ -579,7 +579,6 @@ static int newary(struct ipc_namespace *ns, struct ipc_params *params) ns->used_sems += nsems; sem_unlock(sma, -1); - rcu_read_unlock(); return sma->sem_perm.id; } diff --git a/ipc/shm.c b/ipc/shm.c index a9310b6dbbc3..61fae1b6a18e 100644 --- a/ipc/shm.c +++ b/ipc/shm.c @@ -795,7 +795,6 @@ static int newseg(struct ipc_namespace *ns, struct ipc_params *params) error = shp->shm_perm.id; ipc_unlock_object(&shp->shm_perm); - rcu_read_unlock(); return error; no_id: diff --git a/ipc/util.c b/ipc/util.c index cae60f11d9c2..1be691b5dcad 100644 --- a/ipc/util.c +++ b/ipc/util.c @@ -293,7 +293,6 @@ int ipc_addid(struct ipc_ids *ids, struct kern_ipc_perm *new, int limit) idr_preload(GFP_KERNEL); spin_lock_init(&new->lock); - rcu_read_lock(); spin_lock(&new->lock); current_euid_egid(&euid, &egid); @@ -316,7 +315,6 @@ int ipc_addid(struct ipc_ids *ids, struct kern_ipc_perm *new, int limit) if (idx < 0) { new->deleted = true; spin_unlock(&new->lock); - rcu_read_unlock(); return idx; } -- 2.34.1 -- To unsubscribe, send a message with 'unsubscribe linux-aio' in the body to [email protected]. For more info on Linux AIO, see: http://www.kvack.org/aio/ Don't email: <a href=mailto:"[email protected]">[email protected]</a>