ipc: optimize semget/shmget/msgget for lots of keys

[linux.git] / ipc / sem.c

diff --git a/ipc/sem.c b/ipc/sem.c
index 38371e93bfa5c4f101e264b46eab6a19f2f02404..013c7981f3c74ce96369a1ee5835270b4cad6924 100644 (file)
--- a/ipc/sem.c
+++ b/ipc/sem.c
@@ -122,7 +122,7 @@ struct sem_undo {
  * that may be shared among all a CLONE_SYSVSEM task group.
  */
 struct sem_undo_list {
-       atomic_t                refcnt;
+       refcount_t              refcnt;
        spinlock_t              lock;
        struct list_head        list_proc;
 };
@@ -130,8 +130,6 @@ struct sem_undo_list {
 
 #define sem_ids(ns)    ((ns)->ids[IPC_SEM_IDS])
 
-#define sem_checkid(sma, semid)        ipc_checkid(&sma->sem_perm, semid)
-
 static int newary(struct ipc_namespace *, struct ipc_params *);
 static void freeary(struct ipc_namespace *, struct kern_ipc_perm *);
 #ifdef CONFIG_PROC_FS
@@ -185,14 +183,14 @@ static int sysvipc_sem_proc_show(struct seq_file *s, void *it);
 #define sc_semopm      sem_ctls[2]
 #define sc_semmni      sem_ctls[3]
 
-void sem_init_ns(struct ipc_namespace *ns)
+int sem_init_ns(struct ipc_namespace *ns)
 {
        ns->sc_semmsl = SEMMSL;
        ns->sc_semmns = SEMMNS;
        ns->sc_semopm = SEMOPM;
        ns->sc_semmni = SEMMNI;
        ns->used_sems = 0;
-       ipc_init_ids(&ns->ids[IPC_SEM_IDS]);
+       return ipc_init_ids(&ns->ids[IPC_SEM_IDS]);
 }
 
 #ifdef CONFIG_IPC_NS
@@ -200,15 +198,18 @@ void sem_exit_ns(struct ipc_namespace *ns)
 {
        free_ipcs(ns, &sem_ids(ns), freeary);
        idr_destroy(&ns->ids[IPC_SEM_IDS].ipcs_idr);
+       rhashtable_destroy(&ns->ids[IPC_SEM_IDS].key_ht);
 }
 #endif
 
-void __init sem_init(void)
+int __init sem_init(void)
 {
-       sem_init_ns(&init_ipc_ns);
+       const int err = sem_init_ns(&init_ipc_ns);
+
        ipc_init_proc_interface("sysvipc/sem",
                                "       key      semid perms      nsems   uid   gid  cuid  cgid      otime      ctime\n",
                                IPC_SEM_IDS, sysvipc_sem_proc_show);
+       return err;
 }
 
 /**
@@ -1642,7 +1643,7 @@ static inline int get_undo_list(struct sem_undo_list **undo_listp)
                if (undo_list == NULL)
                        return -ENOMEM;
                spin_lock_init(&undo_list->lock);
-               atomic_set(&undo_list->refcnt, 1);
+               refcount_set(&undo_list->refcnt, 1);
                INIT_LIST_HEAD(&undo_list->list_proc);
 
                current->sysvsem.undo_list = undo_list;
@@ -1786,7 +1787,7 @@ SYSCALL_DEFINE4(semtimedop, int, semid, struct sembuf __user *, tsops,
        if (nsops > ns->sc_semopm)
                return -E2BIG;
        if (nsops > SEMOPM_FAST) {
-               sops = kmalloc(sizeof(*sops)*nsops, GFP_KERNEL);
+               sops = kvmalloc(sizeof(*sops)*nsops, GFP_KERNEL);
                if (sops == NULL)
                        return -ENOMEM;
        }
@@ -2018,7 +2019,7 @@ SYSCALL_DEFINE4(semtimedop, int, semid, struct sembuf __user *, tsops,
        rcu_read_unlock();
 out_free:
        if (sops != fast_sops)
-               kfree(sops);
+               kvfree(sops);
        return error;
 }
 
@@ -2041,7 +2042,7 @@ int copy_semundo(unsigned long clone_flags, struct task_struct *tsk)
                error = get_undo_list(&undo_list);
                if (error)
                        return error;
-               atomic_inc(&undo_list->refcnt);
+               refcount_inc(&undo_list->refcnt);
                tsk->sysvsem.undo_list = undo_list;
        } else
                tsk->sysvsem.undo_list = NULL;
@@ -2070,7 +2071,7 @@ void exit_sem(struct task_struct *tsk)
                return;
        tsk->sysvsem.undo_list = NULL;
 
-       if (!atomic_dec_and_test(&ulp->refcnt))
+       if (!refcount_dec_and_test(&ulp->refcnt))
                return;
 
        for (;;) {
@@ -2091,7 +2092,8 @@ void exit_sem(struct task_struct *tsk)
                         * possibility where we exit while freeary() didn't
                         * finish unlocking sem_undo_list.
                         */
-                       spin_unlock_wait(&ulp->lock);
+                       spin_lock(&ulp->lock);
+                       spin_unlock(&ulp->lock);
                        rcu_read_unlock();
                        break;
                }