Messages in this thread Patch in this message | | | Date | Sun, 06 Nov 2011 17:34:27 +0530 | From | "Srivatsa S. Bhat" <> | Subject | Re: [PATCH 05/17] freezer: rename thaw_process() to __thaw_task() and simplify the implementation |
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On 11/01/2011 12:35 AM, Tejun Heo wrote: > thaw_process() now has only internal users - system and cgroup > freezers. Remove the unnecessary return value, rename, unexport and > collapse __thaw_process() into it. This will help further updates to > the freezer code. > > -v2: minor style update as suggested by Matt. > > Signed-off-by: Tejun Heo <tj@kernel.org> > Cc: Paul Menage <menage@google.com> > Cc: Matt Helsley <matthltc@us.ibm.com> > --- > include/linux/freezer.h | 3 +-- > kernel/cgroup_freezer.c | 7 +++---- > kernel/freezer.c | 31 ++++++++++++------------------- > kernel/power/process.c | 2 +- > 4 files changed, 17 insertions(+), 26 deletions(-) > > diff --git a/include/linux/freezer.h b/include/linux/freezer.h > index 4a73dd2..253bcfe 100644 > --- a/include/linux/freezer.h > +++ b/include/linux/freezer.h > @@ -45,7 +45,7 @@ static inline bool should_send_signal(struct task_struct *p) > } > > /* Takes and releases task alloc lock using task_lock() */ > -extern int thaw_process(struct task_struct *p); > +extern void __thaw_task(struct task_struct *t); > > extern bool __refrigerator(bool check_kthr_stop); > extern int freeze_processes(void); > @@ -183,7 +183,6 @@ static inline int frozen(struct task_struct *p) { return 0; } > static inline int freezing(struct task_struct *p) { return 0; } > static inline void set_freeze_flag(struct task_struct *p) {} > static inline void clear_freeze_flag(struct task_struct *p) {} > -static inline int thaw_process(struct task_struct *p) { return 1; } > > static inline bool __refrigerator(bool check_kthr_stop) { return false; } > static inline int freeze_processes(void) { return -ENOSYS; } > diff --git a/kernel/cgroup_freezer.c b/kernel/cgroup_freezer.c > index e691818..e7fa0ec 100644 > --- a/kernel/cgroup_freezer.c > +++ b/kernel/cgroup_freezer.c > @@ -130,7 +130,7 @@ struct cgroup_subsys freezer_subsys; > * write_lock css_set_lock (cgroup iterator start) > * task->alloc_lock > * read_lock css_set_lock (cgroup iterator start) > - * task->alloc_lock (inside thaw_process(), prevents race with refrigerator()) > + * task->alloc_lock (inside __thaw_task(), prevents race with refrigerator()) ^^^^^^^^^ Shouldn't this be __refrigerator()?
> * sighand->siglock > */ > static struct cgroup_subsys_state *freezer_create(struct cgroup_subsys *ss, > @@ -300,9 +300,8 @@ static void unfreeze_cgroup(struct cgroup *cgroup, struct freezer *freezer) > struct task_struct *task; > > cgroup_iter_start(cgroup, &it); > - while ((task = cgroup_iter_next(cgroup, &it))) { > - thaw_process(task); > - } > + while ((task = cgroup_iter_next(cgroup, &it))) > + __thaw_task(task); > cgroup_iter_end(cgroup, &it); > > freezer->state = CGROUP_THAWED; > diff --git a/kernel/freezer.c b/kernel/freezer.c > index 57ba75f..8faa0e0 100644 > --- a/kernel/freezer.c > +++ b/kernel/freezer.c > @@ -145,18 +145,8 @@ void cancel_freezing(struct task_struct *p) > } > } > > -static int __thaw_process(struct task_struct *p) > -{ > - if (frozen(p)) { > - p->flags &= ~PF_FROZEN; > - return 1; > - } > - clear_freeze_flag(p); > - return 0; > -} > - > /* > - * Wake up a frozen process > + * Wake up a frozen task > * > * task_lock() is needed to prevent the race with refrigerator() which may ^^^^^^ __refrigerator()?
> * occur if the freezing of tasks fails. Namely, without the lock, if the > @@ -164,15 +154,18 @@ static int __thaw_process(struct task_struct *p) > * refrigerator() could call frozen_process(), in which case the task would be > * frozen and no one would thaw it. > */ > -int thaw_process(struct task_struct *p) > +void __thaw_task(struct task_struct *p) > { > + bool was_frozen; > + > task_lock(p); > - if (__thaw_process(p) == 1) { > - task_unlock(p); > - wake_up_process(p); > - return 1; > - } > + was_frozen = frozen(p); > + if (was_frozen) > + p->flags &= ~PF_FROZEN; > + else > + clear_freeze_flag(p); > task_unlock(p); > - return 0; > + > + if (was_frozen) > + wake_up_process(p); > } > -EXPORT_SYMBOL(thaw_process); > diff --git a/kernel/power/process.c b/kernel/power/process.c > index addbbe5..fe27872 100644 > --- a/kernel/power/process.c > +++ b/kernel/power/process.c > @@ -186,7 +186,7 @@ static void thaw_tasks(bool nosig_only) > if (cgroup_freezing_or_frozen(p)) > continue; > > - thaw_process(p); > + __thaw_task(p); > } while_each_thread(g, p); > read_unlock(&tasklist_lock); > }
Rebasing to latest kernel, we need to do the conversion in mm/oom_kill.c as well, (and consequently add __thaw_task() empty function under !CONFIG_FREEZER, in include/linux/freezer.h)
Thanks, Srivatsa S. Bhat
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