On Fri, 2014-10-24 at 17:25 +0200, Thomas Gleixner wrote: > On Wed, 8 Oct 2014, Mike Galbraith wrote: > > On Wed, 2014-10-08 at 13:04 -0400, Linus Torvalds wrote: > > > On Wed, Oct 8, 2014 at 11:37 AM, Mike Galbraith > > > <[email protected]> wrote: > > > > > > > > 11d4616bd07f38d496bd489ed8fad1dc4d928823 is the first bad commit > > > > commit 11d4616bd07f38d496bd489ed8fad1dc4d928823 > > > > Author: Linus Torvalds <[email protected]> > > > > Date: Thu Mar 20 22:11:17 2014 -0700 > > > > > > > > futex: revert back to the explicit waiter counting code > > > > > > While that revert might make things a tiny bit slower (I hated doing > > > it, but the clever approach sadly didn't work on powerpc and depended > > > on x86 locking semantics), I seriously doubt it's really relevant. > > > It's more likely that the *real* problem itself is very > > > timing-dependent, and the subtle synchronization changes here then > > > expose it or hide it, rather than really fixing anything. > > > > > > So like Thomas, I would suspect a race condition in the futex use, and > > > then the exact futex implementation details are just exposing it > > > incidentally. > > > > Whew, good, futex.c is hard. Heads up chess guys <punt>. > > I wonder whether the barrier fix which got into 3.17 late fixes that > issue as well.
Yes, it did. -Mike -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
