On Mon, 20 Sep 2010 16:11:31 +0200 Ohad Ben-Cohen <ohad@xxxxxxxxxx> wrote: > Occasionally, drivers care about the value that idr associates with > their pointers. > > Today we have idr_get_new_above() which allocates a new idr entry > above or equal to a given starting id, but sometimes drivers need to > force an exact value. > > To overcome this small API gap, drivers are wrapping idr_get_new_above > and then either BUG_ON() or just call idr_remove() and returns -EBUSY > when idr allocates them an id which is different than their requested > value. > > There are only a handful of users who need this (see below. especially > note the i2c comment :), but it might be nice to have such an API (a > bit less of code, and a bit less error prone). > > Would something like the below be desirable/acceptable ? It seems OK to me - it's an improvement over what we have now. > (untested. and i just picked the simplest and straight-forward way to > implement this; obviously it's not optimal since there's no reason to > even allocate an id if we know it's not the id we're looking for. but > it's enough to get the idea, it's not a hot path, and it's what > drivers are doing today) Sure, we can speed it up later if that appears to be necessary. -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
