On Mon, Aug 10, 2020 at 11:12 PM Jens Axboe <axboe@xxxxxxxxx> wrote: > On 8/10/20 3:10 PM, Peter Zijlstra wrote: > > On Mon, Aug 10, 2020 at 03:06:49PM -0600, Jens Axboe wrote: > > > >> should work as far as I can tell, but I don't even know if there's a > >> reliable way to do task_in_kernel(). > > > > Only on NOHZ_FULL, and tracking that is one of the things that makes it > > so horribly expensive. > > Probably no other way than to bite the bullet and just use TWA_SIGNAL > unconditionally... Why are you trying to avoid using TWA_SIGNAL? Is there a specific part of handling it that's particularly slow?