diff options
| author | Ross Lagerwall <ross.lagerwall@citrix.com> | 2014-08-18 10:41:36 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-10-05 13:41:03 -0700 |
| commit | 2edbf3c6af0f5f1f9d2ef00a15339c10beaff405 (patch) | |
| tree | 83a81c7c36d8c36d0ae28327c9d7d8e0a9fd1e1d | |
| parent | 52446fb9b34505cb168b5cebe2274b24b69fc7f6 (diff) | |
xen/manage: Always freeze/thaw processes when suspend/resuming
commit 61a734d305e16944b42730ef582a7171dc733321 upstream.
Always freeze processes when suspending and thaw processes when resuming
to prevent a race noticeable with HVM guests.
This prevents a deadlock where the khubd kthread (which is designed to
be freezable) acquires a usb device lock and then tries to allocate
memory which requires the disk which hasn't been resumed yet.
Meanwhile, the xenwatch thread deadlocks waiting for the usb device
lock.
Freezing processes fixes this because the khubd thread is only thawed
after the xenwatch thread finishes resuming all the devices.
Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/xen/manage.c | 7 |
1 files changed, 0 insertions, 7 deletions
diff --git a/drivers/xen/manage.c b/drivers/xen/manage.c index 5f1e1f3cd186..f8bb36f9d9ce 100644 --- a/drivers/xen/manage.c +++ b/drivers/xen/manage.c @@ -103,16 +103,11 @@ static void do_suspend(void) shutting_down = SHUTDOWN_SUSPEND; -#ifdef CONFIG_PREEMPT - /* If the kernel is preemptible, we need to freeze all the processes - to prevent them from being in the middle of a pagetable update - during suspend. */ err = freeze_processes(); if (err) { pr_err("%s: freeze failed %d\n", __func__, err); goto out; } -#endif err = dpm_suspend_start(PMSG_FREEZE); if (err) { @@ -157,10 +152,8 @@ out_resume: dpm_resume_end(si.cancelled ? PMSG_THAW : PMSG_RESTORE); out_thaw: -#ifdef CONFIG_PREEMPT thaw_processes(); out: -#endif shutting_down = SHUTDOWN_INVALID; } #endif /* CONFIG_HIBERNATE_CALLBACKS */ |