On Mon 26-09-11 19:58:50, Rusty Russell wrote: > On Mon, 26 Sep 2011 10:28:37 +0200, Michal Hocko <mhocko@xxxxxxx> wrote: > > On Fri 26-08-11 11:13:40, David Rientjes wrote: > > > I'd love to be able to do a thaw on a PF_FROZEN task in the oom killer > > > followed by a SIGKILL if that task is selected for oom kill without an > > > heuristic change. Not sure if that's possible, so we'll wait for Rafael > > > to chime in. > > > > We have discussed that with Rafael and it should be safe to do that. See > > the patch bellow. > > The only place I am not entirely sure about is run_guest > > (drivers/lguest/core.c). It seems that the code is able to cope with > > signals but it also calls lguest_arch_run_guest after try_to_freeze. > > Yes; if you want to kill things in the refrigerator(), then will a > > if (cpu->lg->dead || task_is_dead(current)) > break; > > Work? The task is not dead yet. We should rather check for pending signals. Can we just move try_to_freeze up before the pending signals check? diff --git a/drivers/lguest/core.c b/drivers/lguest/core.c index 2535933..a513509 100644 --- a/drivers/lguest/core.c +++ b/drivers/lguest/core.c @@ -232,6 +232,12 @@ int run_guest(struct lg_cpu *cpu, unsigned long __user *user) } } + /* + * All long-lived kernel loops need to check with this horrible + * thing called the freezer. If the Host is trying to suspend, + * it stops us. + */ + try_to_freeze(); /* Check for signals */ if (signal_pending(current)) return -ERESTARTSYS; @@ -246,13 +252,6 @@ int run_guest(struct lg_cpu *cpu, unsigned long __user *user) try_deliver_interrupt(cpu, irq, more); /* - * All long-lived kernel loops need to check with this horrible - * thing called the freezer. If the Host is trying to suspend, - * it stops us. - */ - try_to_freeze(); - - /* * Just make absolutely sure the Guest is still alive. One of * those hypercalls could have been fatal, for example. */ > That break means we return to the read() syscall pretty much > immediately. > > Thanks for the CC, > Rusty. -- Michal Hocko SUSE Labs SUSE LINUX s.r.o. Lihovarska 1060/12 190 00 Praha 9 Czech Republic -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>