On 2017-09-21 13:51:35 [-0400], Steven Rostedt wrote: > On Thu, 21 Sep 2017 19:35:12 +0200 > Sebastian Andrzej Siewior <bige...@linutronix.de> wrote: > > > No, it does not. It fixes only one and this one was introduced while I > > rebased RT ontop of the futex work - the patch "futex: Fix bug on when a > > requeued RT task times out" to be exact. > > If you look at the code in the v4.9 or v4.11 RT then you see that there > > is just rt_mutex_start_proxy_lock()() and this function acquires and > > releases ->wait_lock lock. After the futex rework the locking changed > > and I missed to adapt the RT-only patch I mentioned. > > Again: without the patch, the ->wait_lock is dropped twice in the error > > case here: once here and the second time by the caller and this has only > > been like this since the futex-rework. So this does not apply to v4.1-RT > > for instance because the futex rework got into v4.9.18-rt14 and I don't > > recall that you backported it. > > Looking at the code, you are correct that it only fixes one bug. But I > would still include a statement about why there's a change in semantics > here (there still is, the old way enabled interrupts before returning, > this way does not). The reason this is OK, is because the > spin_unlock_irq() is called immediately after this function.
The spin_lock_irq() was never called in this function. I will update it. > -- Steve Sebastian
