On Mon, Jul 31, 2023 at 01:42:09PM -0500, Bob Pearson wrote:
> On 7/31/23 13:31, Jason Gunthorpe wrote:
> > 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@xxxxxxxxx>
> >>>> ---
> >>>> 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.
>
> rxe_pool_get_index() is the only 'correct' way to look up the pointer and
> it checks the valid state (now). Scanning the xarray or just looking up
> the qp is something outside the scope of the normal flows. Like listing
> orphan objects on module exit.
Maybe at this instance, but people keep changing this and it is
fundamentally wrong to store a pointer to an incompletely initialized
memory for other threads to see.
Especially for some minor debugging feature.
Jason
