Tian, Kevin
2007-Feb-06 08:16 UTC
[Xen-devel] [PATCH 4/6] Limit new suspend steps only to driver domain
Anyway to wait and freeze all processes is overhead to some
extent. This patch adds a check upon whether current one
is driver domain. If not, keep original suspend sequence.
Signed-off-by Kevin Tian <kevin.tian@intel.com>
diff -r ac24ecea9595 -r f30f5edc3da8
linux-2.6-xen-sparse/drivers/xen/core/machine_reboot.c
--- a/linux-2.6-xen-sparse/drivers/xen/core/machine_reboot.c Mon Feb
05 17:30:13 2007 +0800
+++ b/linux-2.6-xen-sparse/drivers/xen/core/machine_reboot.c Mon Feb
05 17:34:13 2007 +0800
@@ -18,6 +18,7 @@
#include <xen/gnttab.h>
#include <xen/xencons.h>
#include <xen/cpu_hotplug.h>
+#include <linux/pci.h>
#if defined(__i386__) || defined(__x86_64__)
@@ -130,9 +131,19 @@ static void post_suspend(int suspend_can
#endif
+/* Check driver domain to see whether to freeze processes */
+static inline int check_driver_domain(void)
+{
+ struct pci_device_id ids = {PCI_ANY_ID, PCI_ANY_ID, PCI_ANY_ID,
+ PCI_ANY_ID, 0, 0, 0};
+
+ return pci_dev_present(&ids);
+}
+
int __xen_suspend(void)
{
int err, suspend_cancelled;
+ int driver;
extern void time_resume(void);
@@ -151,13 +162,16 @@ int __xen_suspend(void)
if (err)
return err;
- if (freeze_processes()) {
- err = -EAGAIN;
- goto Thaw;
- }
-
- if ((err = device_suspend(PMSG_SUSPEND)))
- goto Thaw;
+ driver = check_driver_domain();
+ if (driver) {
+ if (freeze_processes()) {
+ err = -EAGAIN;
+ goto Thaw;
+ }
+
+ if ((err = device_suspend(PMSG_SUSPEND)))
+ goto Thaw;
+ }
xenbus_suspend();
@@ -167,7 +181,7 @@ int __xen_suspend(void)
local_irq_disable();
preempt_enable();
- if ((err = device_power_down(PMSG_SUSPEND)))
+ if (driver && (err = device_power_down(PMSG_SUSPEND)))
goto Thaw;
gnttab_suspend();
@@ -187,7 +201,8 @@ int __xen_suspend(void)
if (!suspend_cancelled)
irq_resume();
- device_power_up();
+ if (driver)
+ device_power_up();
time_resume();
@@ -202,10 +217,12 @@ int __xen_suspend(void)
xenbus_suspend_cancel();
}
- device_resume();
+ if (driver)
+ device_resume();
err = 0;
Thaw:
- thaw_processes();
+ if (driver)
+ thaw_processes();
smp_resume();
return err;
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