On Thu, Apr 14, 2016 at 10:50:28AM +0200, Miroslav Benes wrote: > On Thu, 14 Apr 2016, Miroslav Benes wrote: > > > On Fri, 25 Mar 2016, Josh Poimboeuf wrote: > > > > > Update a tasks's universe when returning from a system call or user > > > space interrupt, or after handling a signal. > > > > > > This greatly increases the chances of a patch operation succeeding. If > > > a task is I/O bound, it can switch universes when returning from a > > > system call. If a task is CPU bound, it can switch universes when > > > returning from an interrupt. If a task is sleeping on a to-be-patched > > > function, the user can send SIGSTOP and SIGCONT to force it to switch. > > > > > > Since the idle "swapper" tasks don't ever exit the kernel, they're > > > updated from within the idle loop. > > > > Well, I am still not familiarized enough with Andy's recent rework of > > entry stuff, but I think all of this is correct. Maybe I would add > > a note to the changelog, that since TIF_KLP_NEED_UPDATE is defined 14th > > bit it is also automatically included in _TIF_ALLWORK_MASKS. > > And I forgot to add that I would try to prepare similar thing for s390 and > maybe powerpc (taking recent development there into account). That's gonna > be fun :) Yeah, good point. I've glanced at the entry code for both architectures and I don't think it'll be too bad, though the devil's in the details. -- Josh -- To unsubscribe from this list: send the line "unsubscribe live-patching" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
