Messages in this thread | | | Subject | Re: [PATCH 2/3 v2] futex: avoid double wake up in futex_wake() on -RT | From | Davidlohr Bueso <> | Date | Thu, 16 Apr 2015 09:22:45 -0700 |
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On Thu, 2015-04-16 at 17:54 +0200, Peter Zijlstra wrote: > On Thu, Apr 16, 2015 at 07:42:55AM -0700, Davidlohr Bueso wrote: > > On Thu, 2015-04-16 at 12:16 +0200, Peter Zijlstra wrote: > > > But if we decide we want to go do this, I'd propose we reintroduce this > > > delayed wake list thing again. > > > > Given that futexes aren't the only potential users, I definitely agree. > > Lemme cleanup the patches and I'll resend. Now, one thing I wonder about > > is if we should bother making it a delayed list a plist instead -- as > > not all users would consider rt-tasks like futexes do. > > plist don't work and should not be used for tasks anymore. I suppose I > should go rip them out of futexes too. If you want to make the thing > priority aware we should probably abstract the rb-tree from rtmutex.c
Hmm yeah I noticed that, but a tree for this thing seems like an overkill imho. I mean, at least wrt futexes, I don't think there would ever be a nr_wake - within a single futex call as we use the list on the stack - value large enough to even remotely justify the data structure.
Oh and that reminds me, we should update the rtmutex docs, it still mentions plist -- but replacing those nice ascii art lists with trees is evil ;)
Thanks, Davidlohr
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