ipc/sem.c: add a per-semaphore pending list
[linux-2.6.git] / ipc / sem.c
index eac3f46..4252a8e 100644 (file)
--- a/ipc/sem.c
+++ b/ipc/sem.c
@@ -241,6 +241,7 @@ static int newary(struct ipc_namespace *ns, struct ipc_params *params)
        key_t key = params->key;
        int nsems = params->u.nsems;
        int semflg = params->flg;
+       int i;
 
        if (!nsems)
                return -EINVAL;
@@ -273,6 +274,11 @@ static int newary(struct ipc_namespace *ns, struct ipc_params *params)
        ns->used_sems += nsems;
 
        sma->sem_base = (struct sem *) &sma[1];
+
+       for (i = 0; i < nsems; i++)
+               INIT_LIST_HEAD(&sma->sem_base[i].sem_pending);
+
+       sma->complex_count = 0;
        INIT_LIST_HEAD(&sma->sem_pending);
        INIT_LIST_HEAD(&sma->list_id);
        sma->sem_nsems = nsems;
@@ -419,6 +425,15 @@ static void wake_up_sem_queue(struct sem_queue *q, int error)
        preempt_enable();
 }
 
+static void unlink_queue(struct sem_array *sma, struct sem_queue *q)
+{
+       list_del(&q->list);
+       if (q->nsops == 1)
+               list_del(&q->simple_list);
+       else
+               sma->complex_count--;
+}
+
 /* Go through the pending queue for the indicated semaphore
  * looking for tasks that can be completed.
  */
@@ -438,7 +453,7 @@ again:
                if (error > 0)
                        continue;
 
-               list_del(&q->list);
+               unlink_queue(sma, q);
 
                /*
                 * The next operation that must be checked depends on the type
@@ -532,8 +547,7 @@ static void freeary(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp)
 
        /* Wake up all pending processes and let them fail with EIDRM. */
        list_for_each_entry_safe(q, tq, &sma->sem_pending, list) {
-               list_del(&q->list);
-
+               unlink_queue(sma, q);
                wake_up_sem_queue(q, -EIDRM);
        }
 
@@ -1191,6 +1205,19 @@ SYSCALL_DEFINE4(semtimedop, int, semid, struct sembuf __user *, tsops,
        else
                list_add(&queue.list, &sma->sem_pending);
 
+       if (nsops == 1) {
+               struct sem *curr;
+               curr = &sma->sem_base[sops->sem_num];
+
+               if (alter)
+                       list_add_tail(&queue.simple_list, &curr->sem_pending);
+               else
+                       list_add(&queue.simple_list, &curr->sem_pending);
+       } else {
+               INIT_LIST_HEAD(&queue.simple_list);
+               sma->complex_count++;
+       }
+
        queue.status = -EINTR;
        queue.sleeper = current;
        current->state = TASK_INTERRUPTIBLE;
@@ -1232,7 +1259,7 @@ SYSCALL_DEFINE4(semtimedop, int, semid, struct sembuf __user *, tsops,
         */
        if (timeout && jiffies_left == 0)
                error = -EAGAIN;
-       list_del(&queue.list);
+       unlink_queue(sma, &queue);
 
 out_unlock_free:
        sem_unlock(sma);
@@ -1375,7 +1402,7 @@ static int sysvipc_sem_proc_show(struct seq_file *s, void *it)
        struct sem_array *sma = it;
 
        return seq_printf(s,
-                         "%10d %10d  %4o %10lu %5u %5u %5u %5u %10lu %10lu\n",
+                         "%10d %10d  %4o %10u %5u %5u %5u %5u %10lu %10lu\n",
                          sma->sem_perm.key,
                          sma->sem_perm.id,
                          sma->sem_perm.mode,