Re: [PATCH 1/2] lguest: move process freezing before pending signals check

Michal Hocko
2011-10-12T06:55:08Z

Hi Rusty,
what is the current state of this patch? Are you planning to push it for
3.2?

Thanks

On Tue 27-09-11 08:56:03, Michal Hocko wrote:
> run_guest tries to freeze the current process after it has handled
> pending interrupts and before it calls lguest_arch_run_guest.
> This doesn't work nicely if the task has been killed while being frozen
> and when we want to handle that signal as soon as possible.
> Let's move try_to_freeze before we check for pending signal so that we
> can get out of the loop as soon as possible.
>
> Signed-off-by: Michal Hocko <mhocko@suse.cz>
> Acked-by: Rusty Russell <rusty@rustcorp.com.au>
> ---
> drivers/lguest/core.c | 14 +++++++-------
> 1 files changed, 7 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/lguest/core.c b/drivers/lguest/core.c
> index 2535933..e7dda91 100644
> --- a/drivers/lguest/core.c
> +++ b/drivers/lguest/core.c
> @@ -232,6 +232,13 @@ 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 +253,6 @@ 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.
> */
> --
> 1.7.5.4