Sorry for the late reply; I've been swamped and am behind on my upstream mail.
On Wed, Mar 20, 2013 at 12:55 PM, Rik van Riel <r...@surriel.com> wrote:
> +static inline int sem_lock(struct sem_array *sma, struct sembuf *sops,
> + int nsops)
> +{
> + int locknum;
> + if (nsops == 1 && !sma->complex_count) {
> + struct sem *sem = sma->sem_base + sops->sem_num;
> +
> + /* Lock just the semaphore we are interested in. */
> + spin_lock(&sem->lock);
> +
> + /*
> + * If sma->complex_count was set while we were spinning,
> + * we may need to look at things we did not lock here.
> + */
> + if (unlikely(sma->complex_count)) {
> + spin_unlock(&sma->sem_perm.lock);
I believe this should be spin_unlock(&sem->lock) instead ?
> + goto lock_all;
> + }
> + locknum = sops->sem_num;
> + } else {
> + int i;
> + /* Lock the sem_array, and all the semaphore locks */
> + lock_all:
> + spin_lock(&sma->sem_perm.lock);
> + for (i = 0; i < sma->sem_nsems; i++) {
Do we have to lock every sem from the array instead of just the ones
that are being operated on in sops ?
(I'm not sure either way, as I don't fully understand the queueing of
complex ops)
If we want to keep the loop as is, then we may at least remove the
sops argument to sem_lock() since we only care about nsops.
> + struct sem *sem = sma->sem_base + i;
> + spin_lock(&sem->lock);
> + }
> + locknum = -1;
> + }
> + return locknum;
> +}
That's all I have. Very nice test results BTW!
Reviewed-by: Michel Lespinasse <wal...@google.com>
--
Michel "Walken" Lespinasse
A program is never fully debugged until the last user dies.
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