PM / Hibernate: document open(/dev/snapshot) side effects

Opening and closing /dev/snapshot causes the kernel to carry out
some hibernate preparations that should be documented.

[rjw: Added the changelog.]

Signed-off-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
This commit is contained in:
Pavel Machek 2010-04-23 20:32:29 +02:00 committed by Rafael J. Wysocki
parent c92445fadb
commit bc6a0cbd57

View file

@ -24,6 +24,10 @@ assumed to be in the resume mode. The device cannot be open for simultaneous
reading and writing. It is also impossible to have the device open more than
once at a time.
Even opening the device has side effects. Data structures are
allocated, and PM_HIBERNATION_PREPARE / PM_RESTORE_PREPARE chains are
called.
The ioctl() commands recognized by the device are:
SNAPSHOT_FREEZE - freeze user space processes (the current process is