On 8/10/20 3:26 PM, Jann Horn wrote:
On Mon, Aug 10, 2020 at 11:12 PM Jens Axboe axboe@kernel.dk 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?
Not particularly slow, but it's definitely heavier than TWA_RESUME. And as we're driving any pollable async IO through this, just trying to ensure it's as light as possible.
It's not a functional thing, just efficiency.