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Diffstat (limited to 'Documentation/ABI/testing/sysfs-power')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-power | 17 |
1 files changed, 16 insertions, 1 deletions
diff --git a/Documentation/ABI/testing/sysfs-power b/Documentation/ABI/testing/sysfs-power index d882f809387..dcff4d0623a 100644 --- a/Documentation/ABI/testing/sysfs-power +++ b/Documentation/ABI/testing/sysfs-power @@ -21,7 +21,7 @@ Description: these states. What: /sys/power/disk -Date: August 2006 +Date: September 2006 Contact: Rafael J. Wysocki <rjw@sisk.pl> Description: The /sys/power/disk file controls the operating mode of the @@ -39,6 +39,19 @@ Description: 'reboot' - the memory image will be saved by the kernel and the system will be rebooted. + Additionally, /sys/power/disk can be used to turn on one of the + two testing modes of the suspend-to-disk mechanism: 'testproc' + or 'test'. If the suspend-to-disk mechanism is in the + 'testproc' mode, writing 'disk' to /sys/power/state will cause + the kernel to disable nonboot CPUs and freeze tasks, wait for 5 + seconds, unfreeze tasks and enable nonboot CPUs. If it is in + the 'test' mode, writing 'disk' to /sys/power/state will cause + the kernel to disable nonboot CPUs and freeze tasks, shrink + memory, suspend devices, wait for 5 seconds, resume devices, + unfreeze tasks and enable nonboot CPUs. Then, we are able to + look in the log messages and work out, for example, which code + is being slow and which device drivers are misbehaving. + The suspend-to-disk method may be chosen by writing to this file one of the accepted strings: @@ -46,6 +59,8 @@ Description: 'platform' 'shutdown' 'reboot' + 'testproc' + 'test' It will only change to 'firmware' or 'platform' if the system supports that. |