The semctl GETZCNT returns the number of semops waiting for the specified semaphore to become zero. After changeset 9f1bc2c, the semops waiting on just one semaphore are waiting on that semaphore's list.
In order to return the correct count, we have to walk that list too, in addition to the sem_array's list for complex operations. This bug broke dbench; it works again with this patch applied. Signed-off-by: Rik van Riel <[email protected]> Reported-by: Kent Overstreet <[email protected]> Tested-by: Kent Overstreet <[email protected]> --- ipc/sem.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/ipc/sem.c b/ipc/sem.c index 899b598..04b264d 100644 --- a/ipc/sem.c +++ b/ipc/sem.c @@ -815,6 +815,13 @@ static int count_semzcnt (struct sem_array * sma, ushort semnum) struct sem_queue * q; semzcnt = 0; + list_for_each_entry(q, &sma->sem_base[semnum].sem_pending, list) { + struct sembuf * sops = q->sops; + BUG_ON(sops->sem_num != semnum); + if ((sops->sem_op == 0) && !(sops->sem_flg & IPC_NOWAIT)) + semzcnt++; + } + list_for_each_entry(q, &sma->sem_pending, list) { struct sembuf * sops = q->sops; int nsops = q->nsops; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
