Messages in this thread Patch in this message | | | From | "Rafael J. Wysocki" <> | Subject | Re: [PATCH 1/4] swsusp: Untangle thaw_processes | Date | Sun, 19 Nov 2006 13:01:56 +0100 |
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Hi,
On Sunday, 19 November 2006 03:04, Pavel Machek wrote: > Hi! > > > Move the loop from thaw_processes() to a separate function and call it > > independently for kernel threads and user space processes so that the order > > of thawing tasks is clearly visible. > > > > Drop thaw_kernel_threads() which is never used. > > > > Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> > > --- > > include/linux/freezer.h | 6 ----- > > kernel/power/process.c | 55 +++++++++++++++++++++++++++--------------------- > > 2 files changed, 33 insertions(+), 28 deletions(-) > > > > Index: linux-2.6.19-rc5-mm2/include/linux/freezer.h > > =================================================================== > > --- linux-2.6.19-rc5-mm2.orig/include/linux/freezer.h > > +++ linux-2.6.19-rc5-mm2/include/linux/freezer.h > > @@ -1,8 +1,5 @@ > > /* Freezer declarations */ > > > > -#define FREEZER_KERNEL_THREADS 0 > > -#define FREEZER_ALL_THREADS 1 > > - > > #ifdef CONFIG_PM > > /* > > * Check if a process has been frozen > > @@ -60,8 +57,7 @@ static inline void frozen_process(struct > > > > extern void refrigerator(void); > > extern int freeze_processes(void); > > -#define thaw_processes() do { thaw_some_processes(FREEZER_ALL_THREADS); } while(0) > > -#define thaw_kernel_threads() do { thaw_some_processes(FREEZER_KERNEL_THREADS); } while(0) > > +extern void thaw_processes(void); > > > > static inline int try_to_freeze(void) > > { > > Index: linux-2.6.19-rc5-mm2/kernel/power/process.c > > =================================================================== > > --- linux-2.6.19-rc5-mm2.orig/kernel/power/process.c > > +++ linux-2.6.19-rc5-mm2/kernel/power/process.c > > @@ -20,6 +20,8 @@ > > */ > > #define TIMEOUT (20 * HZ) > > > > +#define FREEZER_KERNEL_THREADS 0 > > +#define FREEZER_USER_SPACE 1 > > The variable is named "is_user_space"... so maybe the defines are not > strictly needed?
Not strlctly, but if I see
thaw_tasks(FREEZER_KERNEL_THREADS); thaw_tasks(FREEZER_USER_SPACE);
I can figure out what's going on even without looking at thaw_tasks().
> > + do_each_thread(g, p) { > > + if (!freezeable(p)) > > + continue; > > > > + if (is_user_space(p)) { > > + if (!thaw_user_space) > > + continue; > > + } else { > > + if (thaw_user_space) > > + continue; > > + } > > if (is_user_space(p) != thaw_user_space) > continue;
Ah, good idea. In fact I prefer if (is_user_space(p) == !thaw_user_space), because it will work even if thaw_user_space is different to 1 and 0.
Revised patch follows.
--- Move the loop from thaw_processes() to a separate function and call it independently for kernel threads and user space processes so that the order of thawing tasks is clearly visible.
Drop thaw_kernel_threads() which is never used.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> --- include/linux/freezer.h | 6 ----- kernel/power/process.c | 53 ++++++++++++++++++++++++++---------------------- 2 files changed, 30 insertions(+), 29 deletions(-)
Index: linux-2.6.19-rc5-mm2/include/linux/freezer.h =================================================================== --- linux-2.6.19-rc5-mm2.orig/include/linux/freezer.h +++ linux-2.6.19-rc5-mm2/include/linux/freezer.h @@ -1,8 +1,5 @@ /* Freezer declarations */ -#define FREEZER_KERNEL_THREADS 0 -#define FREEZER_ALL_THREADS 1 - #ifdef CONFIG_PM /* * Check if a process has been frozen @@ -60,8 +57,7 @@ static inline void frozen_process(struct extern void refrigerator(void); extern int freeze_processes(void); -#define thaw_processes() do { thaw_some_processes(FREEZER_ALL_THREADS); } while(0) -#define thaw_kernel_threads() do { thaw_some_processes(FREEZER_KERNEL_THREADS); } while(0) +extern void thaw_processes(void); static inline int try_to_freeze(void) { Index: linux-2.6.19-rc5-mm2/kernel/power/process.c =================================================================== --- linux-2.6.19-rc5-mm2.orig/kernel/power/process.c +++ linux-2.6.19-rc5-mm2/kernel/power/process.c @@ -20,6 +20,8 @@ */ #define TIMEOUT (20 * HZ) +#define FREEZER_KERNEL_THREADS 0 +#define FREEZER_USER_SPACE 1 static inline int freezeable(struct task_struct * p) { @@ -79,6 +81,11 @@ static void cancel_freezing(struct task_ } } +static inline int is_user_space(struct task_struct *p) +{ + return p->mm && !(p->flags & PF_BORROWED_MM); +} + /* 0 = success, else # of processes that we failed to stop */ int freeze_processes(void) { @@ -103,10 +110,9 @@ int freeze_processes(void) cancel_freezing(p); continue; } - if (p->mm && !(p->flags & PF_BORROWED_MM)) { - /* The task is a user-space one. - * Freeze it unless there's a vfork completion - * pending + if (is_user_space(p)) { + /* Freeze the task unless there is a vfork + * completion pending */ if (!p->vfork_done) freeze_process(p); @@ -155,31 +161,30 @@ int freeze_processes(void) return 0; } -void thaw_some_processes(int all) +static void thaw_tasks(int thaw_user_space) { struct task_struct *g, *p; - int pass = 0; /* Pass 0 = Kernel space, 1 = Userspace */ - printk("Restarting tasks... "); read_lock(&tasklist_lock); - do { - do_each_thread(g, p) { - /* - * is_user = 0 if kernel thread or borrowed mm, - * 1 otherwise. - */ - int is_user = !!(p->mm && !(p->flags & PF_BORROWED_MM)); - if (!freezeable(p) || (is_user != pass)) - continue; - if (!thaw_process(p)) - printk(KERN_INFO - "Strange, %s not stopped\n", p->comm); - } while_each_thread(g, p); - - pass++; - } while (pass < 2 && all); - + do_each_thread(g, p) { + if (!freezeable(p)) + continue; + + if (is_user_space(p) == !thaw_user_space) + continue; + + if (!thaw_process(p)) + printk(KERN_WARNING " Strange, %s not stopped\n", + p->comm ); + } while_each_thread(g, p); read_unlock(&tasklist_lock); +} + +void thaw_processes(void) +{ + printk("Restarting tasks ... "); + thaw_tasks(FREEZER_KERNEL_THREADS); + thaw_tasks(FREEZER_USER_SPACE); schedule(); printk("done.\n"); } - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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