On Tue, Dec 08, 2020 at 09:12:36AM +0000, David Laight wrote: > From: Waiman Long > > Sent: 07 December 2020 19:02 > ... > > > How much more difficult would it be to also add a timeout option? > > > I looked at adding one to the mutex code - and fell into a big pile > > > of replicated code. > > > > > > ISTM that one the initial locked exchange (and spin) fails a few > > > extra instructions when heading for the sleep don't really matter > > > > > Actually, I had tried that before. See > > > > https://lore.kernel.org/lkml/20190911150537.19527-1-long...@redhat.com/ > > > > That is for rwsem, but the same can be done for mutex. However, Peter > > didn't seem to like the idea of a timeout parameter. Anyway, it is > > certainly doable if there is a good use case for it. > > 'Unfortunately' my use-case if for an out-of-tree driver. > > The problem I was solving is a status call blocking because > some other code is 'stuck' (probably an oops) with a mutex held.
Working around oopses is not a sane use-case. If you oops, you get to keep all the pieces.
