Kernel Patches Test Suspend States at Runtime
Two patches by Rafael J. Wysocki give users the ability to test suspend and hibernation modes at runtime to detect errors.
The first patch gives users the ability to test the suspend code (suspend to disk) without actually switching to suspend mode. This is a useful approach to discovering driver issues says the developer. The second patch modifies the current hibernation function (Suspend to RAM) source code to achieve the same objective. According to Wysocki, this works better than the current test modes as his code can also test globabl ACPI methods.
The test options add a new "/sys/power/pm_test_level" attribute which accepts numbers between 1 and 5. Each of these values simulates a different suspend or hibernation code level. Wysocki explains the individual values as follows. 5 test the freezing of individual processes. 4 additionally tests suspending of devices. Besides suspending processes and devices, 3 additionally tests platform global methods. 2 adds disabling of nonboot CPUs, and 1 simulates full system suspend.
The developer adds: "if a suspend is started by normal means, the suspend core will perform its normal operations up to the point indicated by the test level. Next, it will wait for 5 seconds and carry out the resume operations needed to transition the system back to the fully functional state". To avoid using the text system, you can set "pm_test_level" to 0. Wysocki’s third patch adds information on his test systems to the documentation.
Subscribe to our Linux Newsletters
Find Linux and Open Source Jobs
Subscribe to our ADMIN Newsletters
Support Our Work
Linux Magazine content is made possible with support from readers like you. Please consider contributing when you’ve found an article to be beneficial.
News
-
Canonical Bumps LTS Support to 12 years
If you're worried that your Ubuntu LTS release won't be supported long enough to last, Canonical has a surprise for you in the form of 12 years of security coverage.
-
Fedora 40 Beta Released Soon
With the official release of Fedora 40 coming in April, it's almost time to download the beta and see what's new.
-
New Pentesting Distribution to Compete with Kali Linux
SnoopGod is now available for your testing needs
-
Juno Computers Launches Another Linux Laptop
If you're looking for a powerhouse laptop that runs Ubuntu, the Juno Computers Neptune 17 v6 should be on your radar.
-
ZorinOS 17.1 Released, Includes Improved Windows App Support
If you need or desire to run Windows applications on Linux, there's one distribution intent on making that easier for you and its new release further improves that feature.
-
Linux Market Share Surpasses 4% for the First Time
Look out Windows and macOS, Linux is on the rise and has even topped ChromeOS to become the fourth most widely used OS around the globe.
-
KDE’s Plasma 6 Officially Available
KDE’s Plasma 6.0 "Megarelease" has happened, and it's brimming with new features, polish, and performance.
-
Latest Version of Tails Unleashed
Tails 6.0 is based on Debian 12 and includes GNOME 43.
-
KDE Announces New Slimbook V with Plenty of Power and KDE’s Plasma 6
If you're a fan of KDE Plasma, you'll be thrilled to hear they've announced a new Slimbook with an AMD CPU and the latest version of KDE Plasma desktop.
-
Monthly Sponsorship Includes Early Access to elementary OS 8
If you want to get a glimpse of what's in the pipeline for elementary OS 8, just set up a monthly sponsorship to help fund its continued existence.