Re: [PATCH 2/3] xen: use freeze/restore/thaw PM events for suspend/resume/chkpt

[Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>]

On Sat, Feb 19, 2011 at 03:12:37PM -0800, Shriram Rajagopalan wrote:
> Use PM_FREEZE, PM_THAW and PM_RESTORE power events for
> suspend/resume/checkpoint functionality, instead of PM_SUSPEND
> and PM_RESUME. Use of these pm events fixes the Xen Guest hangup
> when taking checkpoints. When a suspend event is cancelled
> (while taking checkpoints once/continuously), we use PM_THAW
> instead of PM_RESUME. PM_RESTORE is used when suspend is not
> cancelled. See Documentation/power/devices.txt and linux/pm.h
> for more info about freeze, thaw and restore. The sequence of
> pm events in a suspend-resume scenario is shown below.
> 
>         dpm_suspend_start(PMSG_FREEZE);
> 
>                 dpm_suspend_noirq(PMSG_FREEZE);
> 
>                        sysdev_suspend(PMSG_FREEZE);
>                        cancelled = suspend_hypercall()
>                        sysdev_resume();
> 
>                dpm_resume_noirq(cancelled ? PMSG_THAW : PMSG_RESTORE);
> 
>        dpm_resume_end(cancelled ? PMSG_THAW : PMSG_RESTORE);
> 
> Signed-off-by: Shriram Rajagopalan <rshriram@cs.ubc.ca>
> ---
>  drivers/base/power/main.c                  |    8 ++++----
>  drivers/xen/manage.c                       |   16 ++++++++--------
>  drivers/xen/xenbus/xenbus_probe_frontend.c |    8 +++++---
>  3 files changed, 17 insertions(+), 15 deletions(-)
> 
> diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c
> index 8340497..aab4f60 100644
> --- a/drivers/base/power/main.c
> +++ b/drivers/base/power/main.c
> @@ -233,7 +233,7 @@ static int pm_op(struct device *dev,
>  		}
>  		break;
>  #endif /* CONFIG_SUSPEND */
> -#ifdef CONFIG_HIBERNATION
> +#if defined(CONFIG_HIBERNATION) || defined(CONFIG_XEN_SAVE_RESTORE)

Could we just make CONFIG_XEN_SAVE_RESTORE depend on CONFIG_HIBERANTION?
Like this:


diff --git a/arch/x86/xen/Kconfig b/arch/x86/xen/Kconfig
index 5b54892..838e20c 100644
--- a/arch/x86/xen/Kconfig
+++ b/arch/x86/xen/Kconfig
@@ -38,7 +38,7 @@ config XEN_MAX_DOMAIN_MEMORY
 
 config XEN_SAVE_RESTORE
        bool
-       depends on XEN && PM
+       depends on XEN && PM && HIBERNATION
        default y
 
 config XEN_DEBUG_FS