[ofa-general] Re: [PATCH 1 of 2] libmlx4: Fix race condition in create/destroy QP

[Jack Morgenstein]

On Monday 24 November 2008 23:52, Roland Dreier wrote:
> I think I see one bug at least:
> 
>  > @@ -580,9 +584,12 @@ int mlx4_destroy_qp(struct ibv_qp *ibqp)
>  >  	struct mlx4_qp *qp = to_mqp(ibqp);
>  >  	int ret;
>  >  
>  > +	pthread_mutex_lock(&to_mctx(ibqp->context)->qp_table_mutex);
>  >  	ret = ibv_cmd_destroy_qp(ibqp);
>  > -	if (ret)
>  > +	if (ret) {
>  > +		pthread_mutex_lock(&to_mctx(ibqp->context)->qp_table_mutex);
> 
> The second one should be unlock.
> 
> I'm too tired to check everything carefully enough to be sure it's right
> though.  Can you double-check your lock balancing and error paths, and
> resend fixed patches?
> 
> Thanks,
>   Roland

Ouch!  that is the only bug (after my careful review).
I guess I was tired when I sent them.

I'm resending this patch (fixed) only -- the libmthca patch is OK.

- Jack