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| author | Pavel Machek <pavel@ucw.cz> | 2010-04-23 18:32:29 (GMT) |
|---|---|---|
| committer | Rafael J. Wysocki <rjw@sisk.pl> | 2010-05-10 21:08:17 (GMT) |
| commit | bc6a0cbd576c66995d782331456f68ae63a50af4 (patch) | |
| tree | 0889b8fb0c8d775e32daf179a2a2c5ca9441120c /Documentation/power/userland-swsusp.txt | |
| parent | c92445fadb9179d811b5cb044947ad4712403541 (diff) | |
| download | linux-bc6a0cbd576c66995d782331456f68ae63a50af4.tar.xz | |
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>
Diffstat (limited to 'Documentation/power/userland-swsusp.txt')
| -rw-r--r-- | Documentation/power/userland-swsusp.txt | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/Documentation/power/userland-swsusp.txt b/Documentation/power/userland-swsusp.txt index b967cd9..81680f9 100644 --- a/Documentation/power/userland-swsusp.txt +++ b/Documentation/power/userland-swsusp.txt @@ -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 |