| Message ID | 201107271235.58734.oneukum@suse.de (mailing list archive) |
|---|---|
| State | Rejected, archived |
| Headers | show |
On Wednesday, July 27, 2011, Oliver Neukum wrote: > From ee5849f0bc39d554ef91747ff80c307ac3e05cdd Mon Sep 17 00:00:00 2001 > From: Oliver Neukum <oliver@neukum.org> > Date: Wed, 27 Jul 2011 12:27:00 +0200 > Subject: [PATCH] Unfreeze tasks after an oops in the freezer > > If an oops kills the task suspending or snapshotting > is system, the system is dead because the action is > never completed and the tasks never thawed. > > Signed-off-by: Oliver Neukum <oneukum@suse.de> > --- > include/linux/freezer.h | 2 ++ > kernel/panic.c | 8 ++++++++ > kernel/power/process.c | 11 +++++++++++ > 3 files changed, 21 insertions(+), 0 deletions(-) > > diff --git a/include/linux/freezer.h b/include/linux/freezer.h > index 1effc8b..ab0168a 100644 > --- a/include/linux/freezer.h > +++ b/include/linux/freezer.h > @@ -50,6 +50,7 @@ extern int thaw_process(struct task_struct *p); > extern void refrigerator(void); > extern int freeze_processes(void); > extern void thaw_processes(void); > +extern void thaw_in_oops(void); > > static inline int try_to_freeze(void) > { > @@ -181,6 +182,7 @@ static inline void freezer_count(void) {} > static inline int freezer_should_skip(struct task_struct *p) { return 0; } > static inline void set_freezable(void) {} > static inline void set_freezable_with_signal(void) {} > +static inline void thaw_in_oops(void) {} > > #define wait_event_freezable(wq, condition) \ > wait_event_interruptible(wq, condition) > diff --git a/kernel/panic.c b/kernel/panic.c > index 6923167..ccdd834 100644 > --- a/kernel/panic.c > +++ b/kernel/panic.c > @@ -23,6 +23,7 @@ > #include <linux/init.h> > #include <linux/nmi.h> > #include <linux/dmi.h> > +#include <linux/freezer.h> > > #define PANIC_TIMER_STEP 100 > #define PANIC_BLINK_SPD 18 > @@ -355,6 +356,13 @@ void oops_exit(void) > do_oops_enter_exit(); > print_oops_end_marker(); > kmsg_dump(KMSG_DUMP_OOPS); > + /* > + * if we oops while tasks are frozen, the system > + * will stop dead because the task that would thaw it > + * has been killed. So the system must be explicitly > + * thawed here. > + */ > + thaw_in_oops(); > } > > #ifdef WANT_WARN_ON_SLOWPATH > diff --git a/kernel/power/process.c b/kernel/power/process.c > index 0cf3a27..c03e88b 100644 > --- a/kernel/power/process.c > +++ b/kernel/power/process.c > @@ -22,6 +22,9 @@ > */ > #define TIMEOUT (20 * HZ) > > +/* in case we oops while processes are frozen */ > +static bool tasks_frozen = false; > + > static inline int freezable(struct task_struct * p) > { > if ((p == current) || > @@ -131,6 +134,7 @@ static int try_to_freeze_tasks(bool sig_only) > elapsed_csecs % 100); > } > > + tasks_frozen = (todo == 0); I'd prefer it to be set by freeze_processes(), when oom_killer_disable() is called. > return todo ? -EBUSY : 0; > } > > @@ -189,7 +193,14 @@ void thaw_processes(void) > thaw_workqueues(); > thaw_tasks(true); > thaw_tasks(false); > + tasks_frozen = false; > schedule(); > printk("done.\n"); > } > > +void thaw_in_oops(void) > +{ > + if (tasks_frozen) > + thaw_processes(); > +} > + Thanks, Rafael
diff --git a/include/linux/freezer.h b/include/linux/freezer.h index 1effc8b..ab0168a 100644 --- a/include/linux/freezer.h +++ b/include/linux/freezer.h @@ -50,6 +50,7 @@ extern int thaw_process(struct task_struct *p); extern void refrigerator(void); extern int freeze_processes(void); extern void thaw_processes(void); +extern void thaw_in_oops(void); static inline int try_to_freeze(void) { @@ -181,6 +182,7 @@ static inline void freezer_count(void) {} static inline int freezer_should_skip(struct task_struct *p) { return 0; } static inline void set_freezable(void) {} static inline void set_freezable_with_signal(void) {} +static inline void thaw_in_oops(void) {} #define wait_event_freezable(wq, condition) \ wait_event_interruptible(wq, condition) diff --git a/kernel/panic.c b/kernel/panic.c index 6923167..ccdd834 100644 --- a/kernel/panic.c +++ b/kernel/panic.c @@ -23,6 +23,7 @@ #include <linux/init.h> #include <linux/nmi.h> #include <linux/dmi.h> +#include <linux/freezer.h> #define PANIC_TIMER_STEP 100 #define PANIC_BLINK_SPD 18 @@ -355,6 +356,13 @@ void oops_exit(void) do_oops_enter_exit(); print_oops_end_marker(); kmsg_dump(KMSG_DUMP_OOPS); + /* + * if we oops while tasks are frozen, the system + * will stop dead because the task that would thaw it + * has been killed. So the system must be explicitly + * thawed here. + */ + thaw_in_oops(); } #ifdef WANT_WARN_ON_SLOWPATH diff --git a/kernel/power/process.c b/kernel/power/process.c index 0cf3a27..c03e88b 100644 --- a/kernel/power/process.c +++ b/kernel/power/process.c @@ -22,6 +22,9 @@ */ #define TIMEOUT (20 * HZ) +/* in case we oops while processes are frozen */ +static bool tasks_frozen = false; + static inline int freezable(struct task_struct * p) { if ((p == current) || @@ -131,6 +134,7 @@ static int try_to_freeze_tasks(bool sig_only) elapsed_csecs % 100); } + tasks_frozen = (todo == 0); return todo ? -EBUSY : 0; } @@ -189,7 +193,14 @@ void thaw_processes(void) thaw_workqueues(); thaw_tasks(true); thaw_tasks(false); + tasks_frozen = false; schedule(); printk("done.\n"); } +void thaw_in_oops(void) +{ + if (tasks_frozen) + thaw_processes(); +} +