On Tuesday, January 29, 2013 04:20:15 PM Stephen Warren wrote: > From: Stephen Warren <[email protected]> > > Within hibernate.c, hibernation_platform_enter() is only called from > power_down(), which in turn is only called by hibernate() after having > called hibernation_snapshot(), which in turn calls create_image() which > in turn calls disable_nonboot_cpus(). > > Elsewhere, snapshot_ioctl() allows hibernation_snapshot() and > hibernation_platform_enter() to be invoked via separate IOCTLs, but I > assume the rule is that SNAPSHOT_CREATE_IMAGE must be executed before > IOCTL SNAPSHOT_POWER_OFF, and hence the same ordering applies. > > This means that disable_nonboot_cpus() must have been called already > before hibernation_platform_enter() is entered, and hence the call there > is redundant, so remove it.
No, it isn't. This is a different stage of hibernation and enable_nonboot_cpus() is called before. It works like this: First, before creating the image, the complete "freeze" sequence is carried out which includes disable_nonboot_cpus(). Then, the image is created and the complete "thaw" sequence is carried out which includes enable_nonboot_cpus(). Next, the image is saved and finally the memory taken up by it is freed and hibernation_platform_enter() is called. Roughly. Thanks, Rafael > Signed-off-by: Stephen Warren <[email protected]> > --- > Note: I have compile-tested this on x86-64, but have not attempted to test > it in any way; I'm proposing this patch following code inspection. > --- > kernel/power/hibernate.c | 5 ----- > 1 file changed, 5 deletions(-) > > diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c > index b26f5f1..4ddeacc 100644 > --- a/kernel/power/hibernate.c > +++ b/kernel/power/hibernate.c > @@ -537,10 +537,6 @@ int hibernation_platform_enter(void) > if (error) > goto Platform_finish; > > - error = disable_nonboot_cpus(); > - if (error) > - goto Platform_finish; > - > local_irq_disable(); > syscore_suspend(); > if (pm_wakeup_pending()) { > @@ -555,7 +551,6 @@ int hibernation_platform_enter(void) > Power_up: > syscore_resume(); > local_irq_enable(); > - enable_nonboot_cpus(); > > Platform_finish: > hibernation_ops->finish(); > -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
