blob: cf63f264ce0fe7128b68f5294cd223e49f5d3073 [file] [log] [blame]
What: /proc/<pid>/oom_adj
When: August 2012
Why: /proc/<pid>/oom_adj allows userspace to influence the oom killer's
badness heuristic used to determine which task to kill when the kernel
is out of memory.
The badness heuristic has since been rewritten since the introduction of
this tunable such that its meaning is deprecated. The value was
implemented as a bitshift on a score generated by the badness()
function that did not have any precise units of measure. With the
rewrite, the score is given as a proportion of available memory to the
task allocating pages, so using a bitshift which grows the score
exponentially is, thus, impossible to tune with fine granularity.
A much more powerful interface, /proc/<pid>/oom_score_adj, was
introduced with the oom killer rewrite that allows users to increase or
decrease the badness() score linearly. This interface will replace
A warning will be emitted to the kernel log if an application uses this
deprecated interface. After it is printed once, future warnings will be
suppressed until the kernel is rebooted.