On Thu, 14 Jul 2016 19:14:58 +0200 Sebastian Andrzej Siewior <bige...@linutronix.de> wrote:
> On 07/14/2016 06:13 PM, Steven Rostedt wrote: > >> > >> -# define wakeup_timer_waiters(b) wake_up(&(b)->wait_for_running_timer) > >> +# define wakeup_timer_waiters(b) > >> wake_up_all(&(b)->wait_for_running_timer) > > > > OK, I just received this patch (way after patch 2) > > > > I'm assuming that patch two was done such that you don't do a > > "wake_up_all" under a spinlock. > > No. I pulled in new timer code in and had to redo this part of RT. > > While doing so I noticed that we drop the base lock during timer > invocations and so it could be possible that we have two invocations > of del_timer_sync() on a timer on the same "base" (one after the > other). This is patch #1. > > After that I saw that we do the wake up under the base lock but there > is no reason for it. So here is patch #2. > > Patch #1 is something that could happen in theory and I did not run in > any problem. > OK, so patch 2 was just discovered by reviewing code? -- Steve
