Re: [Xen-devel] pv 2.6.31 (kernel.org) and save/migrate fails, domU BUG

[Jeremy Fitzhardinge <jeremy@xxxxxxxx>]

On 11/10/09 02:08, Pasi Kärkkäinen wrote:
> Hello,
>
> Jeremy: Here's summary about these save/restore problems
> using upstream Linux 2.6.31.5 PV guest.
>
> For me:
>       - I can "xm save" + "xm restore" UP guest, but I get non-fatal
>         BUG in the guest kernel, see [1].
>       - "xm save" fails for SMP guest with "failed to get the suspend evtchn 
> port", see [2].
>
> For Dan:
>       - "xm save" works for UP guest, but "xm restore" doesn't, giving
>         infinite xen_sched_clock related dumps in the guest kernel, see [3].
>       - "xm save" for SMP guest fails, it never ends. I suspect this
>         is the same problem I'm seeing.
>
>
> [1] non-fatal BUG on the guest kernel after "xm restore":
> http://pasik.reaktio.net/xen/debug/dmesg-2.6.31.5-122.fc12.x86_64-saverestore.txt
>   

Does this help:

diff --git a/drivers/xen/manage.c b/drivers/xen/manage.c
index 10d03d7..da57ea1 100644
--- a/drivers/xen/manage.c
+++ b/drivers/xen/manage.c
@@ -43,7 +43,6 @@ static int xen_suspend(void *data)
        if (err) {
                printk(KERN_ERR "xen_suspend: sysdev_suspend failed: %d\n",
                        err);
-               dpm_resume_noirq(PMSG_RESUME);
                return err;
        }
 
@@ -69,7 +68,6 @@ static int xen_suspend(void *data)
        }
 
        sysdev_resume();
-       dpm_resume_noirq(PMSG_RESUME);
 
        return 0;
 }
@@ -108,6 +106,9 @@ static void do_suspend(void)
        }
 
        err = stop_machine(xen_suspend, &cancelled, cpumask_of(0));
+
+       dpm_resume_noirq(PMSG_RESUME);
+
        if (err) {
                printk(KERN_ERR "failed to start xen_suspend: %d\n", err);
                goto out;


> [2] "xm log" contains:
> [2009-11-09 23:44:38 1353] DEBUG (XendCheckpoint:110) [xc_save]: 
> /usr/lib64/xen/bin/xc_save 28 2 0 0 0
> [2009-11-09 23:44:38 1353] INFO (XendCheckpoint:417) xc_save: failed to get 
> the suspend evtchn port
>   

I think this may be a Remus side-effect.

> [3] See the attachment in this email:
> http://lists.xensource.com/archives/html/xen-devel/2009-11/msg00391.html
>   

No idea about this one.  Needs a closer look.

    J

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel