[PATCH] swsusp: debugging
Add a swsusp debugging mode. This does everything that's needed for a suspend
except for actually suspending. So we can look in the log messages and work
out a) what code is being slow and b) which drivers are misbehaving.
(1)
# echo testproc > /sys/power/disk
# echo disk > /sys/power/state
This should turn off the non-boot CPU, freeze all processes, wait for 5
seconds and then thaw the processes and the CPU.
(2)
# echo test > /sys/power/disk
# echo disk > /sys/power/state
This should turn off the non-boot CPU, freeze all processes, shrink
memory, suspend all devices, wait for 5 seconds, resume the devices etc.
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Stefan Seyfried <seife@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/kernel/power/disk.c b/kernel/power/disk.c
index d3a158a..b1fb786 100644
--- a/kernel/power/disk.c
+++ b/kernel/power/disk.c
@@ -71,7 +71,7 @@
static int prepare_processes(void)
{
- int error;
+ int error = 0;
pm_prepare_console();
@@ -84,6 +84,12 @@
goto thaw;
}
+ if (pm_disk_mode == PM_DISK_TESTPROC) {
+ printk("swsusp debug: Waiting for 5 seconds.\n");
+ mdelay(5000);
+ goto thaw;
+ }
+
/* Free memory before shutting down devices. */
if (!(error = swsusp_shrink_memory()))
return 0;
@@ -120,13 +126,21 @@
if (error)
return error;
+ if (pm_disk_mode == PM_DISK_TESTPROC)
+ goto Thaw;
+
suspend_console();
error = device_suspend(PMSG_FREEZE);
if (error) {
resume_console();
printk("Some devices failed to suspend\n");
- unprepare_processes();
- return error;
+ goto Thaw;
+ }
+
+ if (pm_disk_mode == PM_DISK_TEST) {
+ printk("swsusp debug: Waiting for 5 seconds.\n");
+ mdelay(5000);
+ goto Done;
}
pr_debug("PM: snapshotting memory.\n");
@@ -143,16 +157,17 @@
power_down(pm_disk_mode);
else {
swsusp_free();
- unprepare_processes();
- return error;
+ goto Thaw;
}
- } else
+ } else {
pr_debug("PM: Image restored successfully.\n");
+ }
swsusp_free();
Done:
device_resume();
resume_console();
+ Thaw:
unprepare_processes();
return error;
}
@@ -249,6 +264,8 @@
[PM_DISK_PLATFORM] = "platform",
[PM_DISK_SHUTDOWN] = "shutdown",
[PM_DISK_REBOOT] = "reboot",
+ [PM_DISK_TEST] = "test",
+ [PM_DISK_TESTPROC] = "testproc",
};
/**
@@ -303,17 +320,19 @@
}
}
if (mode) {
- if (mode == PM_DISK_SHUTDOWN || mode == PM_DISK_REBOOT)
+ if (mode == PM_DISK_SHUTDOWN || mode == PM_DISK_REBOOT ||
+ mode == PM_DISK_TEST || mode == PM_DISK_TESTPROC) {
pm_disk_mode = mode;
- else {
+ } else {
if (pm_ops && pm_ops->enter &&
(mode == pm_ops->pm_disk_mode))
pm_disk_mode = mode;
else
error = -EINVAL;
}
- } else
+ } else {
error = -EINVAL;
+ }
pr_debug("PM: suspend-to-disk mode set to '%s'\n",
pm_disk_modes[mode]);