On Wed, 2006-11-15 at 17:48 -0500, Edward Goggin wrote: > OK. I was trying not to have to introduce another > prio state because that approach just seems prone > to error. > > I'll give it a try tomorrow. > Ed has a point. An effect of using the special value approach over the flag is a potential conflict with the callouts using the same values. The flag approach isolates his initialization case better. > > -----Original Message----- > > From: Christophe Varoqui [mailto:christophe.varoqui@xxxxxxx] > > Sent: Wednesday, November 15, 2006 5:34 PM > > To: goggin, edward > > Cc: dave.wysochanski@xxxxxxxxxx; dm-devel@xxxxxxxxxx > > Subject: RE: patch to discovery.c to still > > getpathpriorityforpaths with path state of PATH_DOWN > > > > Le mercredi 15 novembre 2006 à 14:48 -0500, Edward Goggin a écrit : > > > On Wednesday, November 15, 2006 1:49 AM, Dave Wysochanski wrote > > > > > > > One other thought I had was the notion of a "priority valid" > > > > flag (or a > > > > special priority value) in the path for the case of > > > > group_by_prio. Set > > > > it to invalid in alloc_path(), then just don't add the path to the > > > > multipath struct in coalesce_paths() if the priority value > > > > was invalid. > > > > Then over in checkerloop(), add the path to the multipath > > map when you > > > > get a valid priority. > > > > > > > > It is more complicated than that I'm sure (e.g. > > checkerloop() assumes > > > > pp->mpp is non-null in places, etc) but seemed like a half-decent > > > > approach to at least consider. > > > > > > > > This approach doesn't take into consideration the general > > case of a > > > > change in path priority though. > > > > > > I very much like the first part of your "priority valid" idea > > > mentioned above. > > > > > > I've enclosed a patch for the first part of your idea. The patch > > > should address the concern you had about recalculating priority > > > for a path when its path state changes from not PATH_DOWN to > > > PATH_DOWN. It now only retrieves the priority for PATH_DOWN > > > paths if the path's priority has never been successfully > > > retrieved before. > > > > > How about the following, clarifying PRIO values and avoiding the > > additional "struct path" element ? > > > > Please have a careful look at the > > multipath/main.c:update_paths change, > > because the (!pp->priority) that was there awfully looks like > > a bug (as > > 0 is not a defined prio value). > > > > Regards, > > cvaroqui > > > > > > -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
