On Fri, 13 Apr 2007 11:31:16 +0400 Oleg Nesterov <[EMAIL PROTECTED]> wrote:
> On top of Eric's > > kthread-dont-depend-on-work-queues-take-2.patch > > Currently kernel threads use sigprocmask(SIG_BLOCK) to protect against > signals. > This doesn't prevent the signal delivery, this only blocks signal_wake_up(). > Every "killall -33 kthreadd" means a "struct siginfo" leak. > > Change kthreadd_setup() to set all handlers to SIG_IGN instead of blocking > them > (make a new helper ignore_signals() for that). If the kernel thread needs some > signal, it should use allow_signal() anyway, and in that case it should not > use > CLONE_SIGHAND. > > Note that we can't change daemonize() (should die!) in the same way, because > it can be used along with CLONE_SIGHAND. This means that allow_signal() still > should unblock the signal to work correctly with daemonize()ed threads. > > However, disallow_signal() doesn't block the signal any longer but ignores it. > > NOTE: with or without this patch the kernel threads are not protected from > handle_stop_signal(), this seems harmless, but not good. I'm seeing 500 zombied instances of khelper (from udev startup). It only happens when the utrace patches are applied. Presumably an interaction between utrace and one of these kthread changes. I'll drop utrace for now. I don't think it's getting much help from being in -mm at present and it's getting increasingly painful to keep it merged against all the other stuff which is happening. Roland, I'll squirt all the extra utrace patches which I have in your direction. Please merge them or hang on to them for later on. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/