On Mon, 2017-09-25 at 08:56 -0400, Gargi Sharma wrote: > idr_get(namespace, id) returns a NULL if id is not present > in the idr tree or returns the pointer to the struct if id is > present in the idr tree. With this function in the idr library, > code for pid allocation can be simplified by calling this function > instead of looking through the pidhash. > +++ b/lib/idr.c > @@ -135,6 +135,17 @@ void *idr_get_next_ext(struct idr *idr, unsigned > long *nextid) >  } >  EXPORT_SYMBOL(idr_get_next_ext); >   > +void * idr_get(struct idr *idr, int *id) > +{ > + struct radix_tree_node *node; > + void __rcu **slot = NULL; > + > + __radix_tree_lookup(&idr->idr_rt, *id, &node, &slot); > + if (!slot) > + return NULL; > + return node; > +} I should have noticed this (much) earlier, but doesn't idr_get do essentially the same thing as idr_find? Also, wouldn't you want to return the pid pointer from slot, rather than a pointer to the entire radix tree node? -- All Rights Reversed.