On Sat, Nov 12, 2011 at 11:07:03PM +0100, Sylvain Munaut wrote:
The patch attached should recover the former behaviour, sorry for missing this case.
Oops, sorry, we actually continued on IRC.
Look at the first few commits of http://cgit.osmocom.org/cgit/libosmocore/log/?h=sylvain/for_jolly
They bring in some fixes/cleanups from the kernel for rbtree then something that fixes the timer. This patch keeps the list head intact and just remove the timer from the tree and re-adds it at the right place.
Hm, I think I found one weird scenario which is not handled fine with your patch.
Say you have two timers A and B. Assume both expire on the same time (and they are inserted in the eviction list in this order, first A, then B). Then, A re-schedules B in its callback. B is reinserted in the tree, however, B is still in the eviction list.
With aeeb7070f84437aa608a3d843346b1efa916d175, since we don't touch the list head. B will be removed from the tree, but I think it should remain there as it has been rescheduled.
Yes, this scenario is strange, but I think we try to cover all possible situations. So I think my patch should be applied instead.
Thanks for collecting the patches that went into rbtree.c in the linux kernel, btw.