Suspend-to-Disk development Information

Suspend to Disk Development Page

Overview

This project will implement what is sometimes known as "Hybrid Suspend".  This means that after the statefile is commited to non-volatile storage, the machine will enter S3 (Suspend to RAM).  If power is retained, the machine will resume quickly from RAM.  But if power is lost, the machine will resume from the disk image.

Commands and utilities will not specifically select "Suspend to RAM" (a.k.a. Sleep) or "Suspend to Disk" (a.k.a. Hibernate), but just "Suspend".  The LibPOWER project will also only provide one entrypoint for suspend: pm_suspend(3pm).  Controls for writing the statefile and the statefile options will be managed by kernel properties that will be adjusted by the Power Management policy interfaces.

Repository

The current repository is named susp2disk.  To get commit permission, please contact Randy Fishel: <randy.fishel@sun.com> or Garrett D'Amore: <garrett@damore.org>

Status

Work is underway.  The current phase is to consolidate code that was previously Sparc or x64 specific into common code where possible, or broken to platform specific files.  This will also be the phase where the code is optimized and cruft removed.  There is also the intention to divorce Suspend from the ppm code.  It added needless overhead and complexity with no benefit.

Shortly thereafter, the save and restore code will be implemented and made available for users to try.

Contribution

Should you desire to help, please contact Randy Fishel: <randy.fishel@sun.com>.