Re: [PATCH RT] kernel/time/posix-timer: avoid schedule() while holding the RCU lock

2018-03-28 Thread Sebastian Andrzej Siewior
On 2018-03-23 16:40:57 [+0100], To linux-rt-us...@vger.kernel.org wrote: while this seems to work I am not quite happy with it and looking into alternatives… Sebastian

Re: [PATCH RT] kernel/time/posix-timer: avoid schedule() while holding the RCU lock

2018-03-28 Thread Sebastian Andrzej Siewior
On 2018-03-23 16:40:57 [+0100], To linux-rt-us...@vger.kernel.org wrote: while this seems to work I am not quite happy with it and looking into alternatives… Sebastian

[PATCH RT] kernel/time/posix-timer: avoid schedule() while holding the RCU lock

2018-03-23 Thread Sebastian Andrzej Siewior
On -RT it is possible that an invocation of timer_set() or timer_delete() preempts an itimer which results in TIMER_RETRY. We can't retry immediately because if the process preempted the softirq then it has a higher priority and will loop and retry forever. As a workaround for -RT the "retry"

[PATCH RT] kernel/time/posix-timer: avoid schedule() while holding the RCU lock

2018-03-23 Thread Sebastian Andrzej Siewior
On -RT it is possible that an invocation of timer_set() or timer_delete() preempts an itimer which results in TIMER_RETRY. We can't retry immediately because if the process preempted the softirq then it has a higher priority and will loop and retry forever. As a workaround for -RT the "retry"