Re: [Xen-devel] [PATCH v4 2/5] xen: use freeze/restore/thaw PM events for suspend/resume/chkpt

[Ian Campbell <Ian.Campbell@xxxxxxxxxx>]

On Wed, 2011-03-16 at 17:19 +0000, 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@xxxxxxxxx>

Looks good, thanks Shriram.

Acked-by: Ian Campbell <ian.campbell@xxxxxxxxxx>

> ---
>  drivers/xen/manage.c                       |   16 ++++++++--------
>  drivers/xen/xenbus/xenbus_probe_frontend.c |    8 +++++---
>  2 files changed, 13 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/xen/manage.c b/drivers/xen/manage.c
> index ebb2928..95143dd 100644
> --- a/drivers/xen/manage.c
> +++ b/drivers/xen/manage.c
> @@ -61,7 +61,7 @@ static void xen_post_suspend(int cancelled)
>       xen_mm_unpin_all();
>  }
>  
> -#ifdef CONFIG_PM_SLEEP
> +#ifdef CONFIG_HIBERNATION
>  static int xen_suspend(void *data)
>  {
>       struct suspend_info *si = data;
> @@ -69,7 +69,7 @@ static int xen_suspend(void *data)
>  
>       BUG_ON(!irqs_disabled());
>  
> -     err = sysdev_suspend(PMSG_SUSPEND);
> +     err = sysdev_suspend(PMSG_FREEZE);
>       if (err) {
>               printk(KERN_ERR "xen_suspend: sysdev_suspend failed: %d\n",
>                       err);
> @@ -118,7 +118,7 @@ static void do_suspend(void)
>       }
>  #endif
>  
> -     err = dpm_suspend_start(PMSG_SUSPEND);
> +     err = dpm_suspend_start(PMSG_FREEZE);
>       if (err) {
>               printk(KERN_ERR "xen suspend: dpm_suspend_start %d\n", err);
>               goto out_thaw;
> @@ -127,7 +127,7 @@ static void do_suspend(void)
>       printk(KERN_DEBUG "suspending xenstore...\n");
>       xs_suspend();
>  
> -     err = dpm_suspend_noirq(PMSG_SUSPEND);
> +     err = dpm_suspend_noirq(PMSG_FREEZE);
>       if (err) {
>               printk(KERN_ERR "dpm_suspend_noirq failed: %d\n", err);
>               goto out_resume;
> @@ -147,7 +147,7 @@ static void do_suspend(void)
>  
>       err = stop_machine(xen_suspend, &si, cpumask_of(0));
>  
> -     dpm_resume_noirq(PMSG_RESUME);
> +     dpm_resume_noirq(si.cancelled ? PMSG_THAW : PMSG_RESTORE);
>  
>       if (err) {
>               printk(KERN_ERR "failed to start xen_suspend: %d\n", err);
> @@ -161,7 +161,7 @@ out_resume:
>       } else
>               xs_suspend_cancel();
>  
> -     dpm_resume_end(PMSG_RESUME);
> +     dpm_resume_end(si.cancelled ? PMSG_THAW : PMSG_RESTORE);
>  
>       /* Make sure timer events get retriggered on all CPUs */
>       clock_was_set();
> @@ -173,7 +173,7 @@ out:
>  #endif
>       shutting_down = SHUTDOWN_INVALID;
>  }
> -#endif       /* CONFIG_PM_SLEEP */
> +#endif       /* CONFIG_HIBERNATION */
>  
>  struct shutdown_handler {
>       const char *command;
> @@ -202,7 +202,7 @@ static void shutdown_handler(struct xenbus_watch *watch,
>               { "poweroff",   do_poweroff },
>               { "halt",       do_poweroff },
>               { "reboot",     do_reboot   },
> -#ifdef CONFIG_PM_SLEEP
> +#ifdef CONFIG_HIBERNATION
>               { "suspend",    do_suspend  },
>  #endif
>               {NULL, NULL},
> diff --git a/drivers/xen/xenbus/xenbus_probe_frontend.c 
> b/drivers/xen/xenbus/xenbus_probe_frontend.c
> index ea83999..b6a2690 100644
> --- a/drivers/xen/xenbus/xenbus_probe_frontend.c
> +++ b/drivers/xen/xenbus/xenbus_probe_frontend.c
> @@ -86,9 +86,11 @@ static struct device_attribute xenbus_frontend_dev_attrs[] 
> = {
>  };
>  
>  static const struct dev_pm_ops xenbus_pm_ops = {
> -     .suspend = xenbus_dev_suspend,
> -     .resume  = xenbus_dev_resume,
> -     .thaw  = xenbus_dev_cancel,
> +     .suspend        = xenbus_dev_suspend,
> +     .resume         = xenbus_dev_resume,
> +     .freeze         = xenbus_dev_suspend,
> +     .thaw           = xenbus_dev_cancel,
> +     .restore        = xenbus_dev_resume,
>  };
>  
>  static struct xen_bus_type xenbus_frontend = {



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