Messages in this thread Patch in this message | | | Date | Mon, 5 Apr 2010 08:38:52 +0200 | From | Pavel Machek <> | Subject | document open(/dev/snapshot) sideeffects -- was Re: [linux-pm] syncing the disks when entering sleep |
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Hi!
> > > Please note that merely _opening_ /dev/snapshot has side effects, so that's > > > not just "three ioctls". > > > > I search Doc*/power/userland-swsusp.txt, and could not find mentions > > of sideeffects. Perhaps that should be fixed? > > Please feel free to make the docs more complete, then.
Yes, something like this?
Signed-off-by: Pavel Machek <pavel@ucw.cz>
--- 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
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