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-rw-r--r--include/linux/sem.h5
-rw-r--r--ipc/sem.c37
2 files changed, 36 insertions, 6 deletions
diff --git a/include/linux/sem.h b/include/linux/sem.h
index 1b191c176bc..8a4adbef8a0 100644
--- a/include/linux/sem.h
+++ b/include/linux/sem.h
@@ -86,6 +86,7 @@ struct task_struct;
struct sem {
int semval; /* current value */
int sempid; /* pid of last operation */
+ struct list_head sem_pending; /* pending single-sop operations */
};
/* One sem_array data structure for each set of semaphores in the system. */
@@ -96,11 +97,13 @@ struct sem_array {
struct sem *sem_base; /* ptr to first semaphore in array */
struct list_head sem_pending; /* pending operations to be processed */
struct list_head list_id; /* undo requests on this array */
- unsigned long sem_nsems; /* no. of semaphores in array */
+ int sem_nsems; /* no. of semaphores in array */
+ int complex_count; /* pending complex operations */
};
/* One queue for each sleeping process in the system. */
struct sem_queue {
+ struct list_head simple_list; /* queue of pending operations */
struct list_head list; /* queue of pending operations */
struct task_struct *sleeper; /* this process */
struct sem_undo *undo; /* undo structure */
diff --git a/ipc/sem.c b/ipc/sem.c
index eac3f46a596..4252a8eb77e 100644
--- 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,