On Thu, Jun 13, 2019 at 11:43:12AM +0200, Christoph Hellwig wrote: > Just check if there is a ->page_free operation set and take care of the > static key enable, as well as the put using device managed resources. > diff --git a/mm/hmm.c b/mm/hmm.c > index c76a1b5defda..6dc769feb2e1 100644 > +++ b/mm/hmm.c > @@ -1378,8 +1378,6 @@ struct hmm_devmem *hmm_devmem_add(const struct hmm_devmem_ops *ops, > void *result; > int ret; > > - dev_pagemap_get_ops(); > - Where was the matching dev_pagemap_put_ops() for this hmm case? This is a bug fix too? The nouveau driver is the only one to actually call this hmm function and it does it as part of a probe function. Seems reasonable, however, in the unlikely event that it fails to init 'dmem' the driver will retain a dev_pagemap_get_ops until it unloads. This imbalance doesn't seem worth worrying about. Reviewed-by: Christoph Hellwig <hch@xxxxxx> Jason
