Re: [PATCH for-next 8/9] RDMA/rxe: Report leaked objects

[Jason Gunthorpe <jgg@nvidia.com>]

On Mon, Jul 31, 2023 at 01:23:59PM -0500, Bob Pearson wrote:
> On 7/31/23 13:15, Jason Gunthorpe wrote:
> > On Fri, Jul 21, 2023 at 03:50:21PM -0500, Bob Pearson wrote:
> >> This patch gives a more detailed list of objects that are not
> >> freed in case of error before the module exits.
> >>
> >> Signed-off-by: Bob Pearson <rpearsonhpe@gmail.com>
> >> ---
> >>  drivers/infiniband/sw/rxe/rxe_pool.c | 12 +++++++++++-
> >>  1 file changed, 11 insertions(+), 1 deletion(-)
> >>
> >> diff --git a/drivers/infiniband/sw/rxe/rxe_pool.c b/drivers/infiniband/sw/rxe/rxe_pool.c
> >> index cb812bd969c6..3249c2741491 100644
> >> --- a/drivers/infiniband/sw/rxe/rxe_pool.c
> >> +++ b/drivers/infiniband/sw/rxe/rxe_pool.c
> >> @@ -113,7 +113,17 @@ void rxe_pool_init(struct rxe_dev *rxe, struct rxe_pool *pool,
> >>  
> >>  void rxe_pool_cleanup(struct rxe_pool *pool)
> >>  {
> >> -	WARN_ON(!xa_empty(&pool->xa));
> >> +	unsigned long index;
> >> +	struct rxe_pool_elem *elem;
> >> +
> >> +	xa_lock(&pool->xa);
> >> +	xa_for_each(&pool->xa, index, elem) {
> >> +		rxe_err_dev(pool->rxe, "%s#%d: Leaked", pool->name,
> >> +				elem->index);
> >> +	}
> >> +	xa_unlock(&pool->xa);
> >> +
> >> +	xa_destroy(&pool->xa);
> >>  }
> > 
> > Is this why? Just count the number of unfinalized objects and report
> > if there is difference, don't mess up the xarray.
> > 
> > Jason
> This is why I made the last change but I really didn't like that there was no
> way to lookup the qp from its index since we were using a NULL xarray entry to
> indicate the state of the qp. Making it explicit, i.e. a variable in the struct
> seems much more straight forward. Not sure why you hated the last
> change.

Because if you don't call finalize abort has to be deterministic, and
abort can't be that if it someone else can access the poitner and, eg,
take a reference.

It breaks the entire model of how the memory ownership works during creation.

Jason