On Wednesday, 7 March 2007 22:07, Pavel Machek wrote:
> Hi!
>
> > Prevent the WARN_ON() in arch/x86_64/kernel/acpi/sleep.c:init_low_mapping()
> > from triggering by disabling nonboot CPUs before we finally enter the
> > platform
> > suspend.
> >
> > Signed-off-by: Rafael J. Wysocki <[EMAIL PROTECTED]>
> > ---
> > kernel/power/disk.c | 1 +
> > kernel/power/user.c | 2 +-
> > 2 files changed, 2 insertions(+), 1 deletion(-)
> >
> > Index: linux-2.6.21-rc2-mm2/kernel/power/disk.c
> > ===================================================================
> > --- linux-2.6.21-rc2-mm2.orig/kernel/power/disk.c
> > +++ linux-2.6.21-rc2-mm2/kernel/power/disk.c
> > @@ -61,6 +61,7 @@ static void power_down(suspend_disk_meth
> > switch(mode) {
> > case PM_DISK_PLATFORM:
> > if (pm_ops && pm_ops->enter) {
> > + disable_nonboot_cpus();
> > kernel_shutdown_prepare(SYSTEM_SUSPEND_DISK);
> > pm_ops->enter(PM_SUSPEND_DISK);
> > break;
>
> ...so, if pm_ops is non-null, power_down does nonboot cpu disabling,
> otherwise we proceed with cpus enabled?
>
> That looks ugly.
>
> Is the warning bogus?
Well, maybe. I'm not sure.
> Or maybe we should *always* disable nonboot cpus in powerdown path?
I think we should do that.
> > Index: linux-2.6.21-rc2-mm2/kernel/power/user.c
> > ===================================================================
> > --- linux-2.6.21-rc2-mm2.orig/kernel/power/user.c
> > +++ linux-2.6.21-rc2-mm2/kernel/power/user.c
> > @@ -398,9 +398,9 @@ static int snapshot_ioctl(struct inode *
> >
> > case PMOPS_ENTER:
> > if (data->platform_suspend) {
> > + disable_nonboot_cpus();
> > kernel_shutdown_prepare(SYSTEM_SUSPEND_DISK);
> > error = pm_ops->enter(PM_SUSPEND_DISK);
> > - error = 0;
> > }
> > break;
>
> Foe an userland application, disabling cpus during pmops_enter is at
> least surprising.......
Yes, but this is not a usual ioctl(). OTOH, we can call enable_nonboot_cpus()
if pm_ops->enter(PM_SUSPEND_DISK) returns an error (otherwise it souldn't
return at all, no?).
Rafael
-
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/
