On Thu, Jan 26, 2023 at 03:12:35PM -0600, Seth Forshee (DigitalOcean) wrote: > On Thu, Jan 26, 2023 at 06:03:16PM +0100, Petr Mladek wrote: > > On Fri 2023-01-20 16:12:20, Seth Forshee (DigitalOcean) wrote: > > > We've fairly regularaly seen liveptches which cannot transition within kpatch's > > > timeout period due to busy vhost worker kthreads. > > > > I have missed this detail. Miroslav told me that we have solved > > something similar some time ago, see > > https://lore.kernel.org/all/20220507174628.2086373-1-song@xxxxxxxxxx/ > > Interesting thread. I had thought about something along the lines of the > original patch, but there are some ideas in there that I hadn't > considered. 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 ;-) -- Josh
