Re: [RFC][PATCH -mm 2/6] Freezer: Do not send signals to kernel threads

Pavel Machek
2007-07-09T23:42:12Z

Hi!

> From: Rafael J. Wysocki <rjw@sisk.pl>
>
> Commit b74d0deb968e1f85942f17080eace015ce3c332c has changed
> recalc_sigpending_tsk() so that it doesn't clear TIF_SIGPENDING. For this
> reason, the freezer should not send fake signals to kernel threads any more,
> since otherwise some of them may run with TIF_SIGPENDING set forever if the
> freezing of kernel threads fails.

Is there some bigger plan why we want this?

I mean, it seems nicer w/o signals, but OTOH it is more lines of code
and kernel/user freezing diverges. Can we just revert few lines,
instead of inserting 100 lines?

> +/*
> + * Freezer-friendly wrappers around wait_event_interruptible() and
> + * wait_event_interruptible_timeout(), originally defined in <linux/wait.h>
> + */
> +
> +#define wait_event_freezable(wq, condition) \
> +({ \
> + int __ret; \
> + do { \
> + __ret = wait_event_interruptible(wq, \
> + (condition) || freezing(current)); \
> + } while (try_to_freeze()); \
> + __ret; \
> +})
> +
> +
> +#define wait_event_freezable_timeout(wq, condition, timeout) \
> +({ \
> + long __ret = timeout; \
> + do { \
> + __ret = wait_event_interruptible_timeout(wq, \
> + (condition) || freezing(current), \
> + __ret); \
> + } while (try_to_freeze()); \
> + __ret; \
> +})

Hohum, but yes, these are nice.

Pavel

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