The kernel can be compiled without support for any memory.swap.* files, or it can be disabled at boot time with the 'swapaccount=0' boot parameter, so if the file doesn't exist log warning indicating the kernel doesn't support the file and the user may need to try using the 'swapaccount=1' boot param. Note that the actual error from the call to fopen() is ENOENT, but that is translated into ENODATA in cg_get_attribute_as_uint64()
System and Service Manager
Details
Most documentation is available on systemd's web site.
Assorted, older, general information about systemd can be found in the systemd Wiki.
Information about build requirements is provided in the README file.
Consult our NEWS file for information about what's new in the most recent systemd versions.
Please see the Hacking guide for information on how to hack on systemd and test your modifications.
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Stable branches with backported patches are available in the stable repo.