On Fri, Jan 27, 2023 at 08:52:38AM -0800, Josh Poimboeuf wrote:

On Fri, Jan 27, 2023 at 11:37:02AM +0100, Peter Zijlstra wrote:

quoted

On Thu, Jan 26, 2023 at 08:43:55PM -0800, Josh Poimboeuf wrote:

quoted

Here's another idea, have we considered this?  Have livepatch set
TIF_NEED_RESCHED on all kthreads to force them into schedule(), and then
have the scheduler call klp_try_switch_task() if TIF_PATCH_PENDING is
set.

Not sure how scheduler folks would feel about that ;-)

Hmmmm, with preemption I guess the above doesn't work for kthreads
calling cond_resched() instead of what vhost_worker() does (explicit
need_resched/schedule).

Though I guess we could hook into cond_resched() too if we make it a
non-NOP for PREEMPT+LIVEPATCH?

-- 
Josh