using ``idle=poll`` is somewhat drastic in many cases, as preventing idle
CPUs from saving almost any energy at all may not be the only effect of it.

For example, on Intel hardware it effectively prevents CPUs from using
P-states (see |cpufreq|) that require any number of CPUs in a package to be
idle, so it very well may hurt single-thread computations performance as well as
energy-efficiency.  Thus using it for performance reasons may not be a good idea
at all.]

Known Issues
    d.    On x86 systems, use the "idle=poll" boot parameter.
        However, please note that use of this parameter can cause
        your CPU to overheat, which may cause thermal throttling
        to degrade your latencies -- and that this degradation can
        be even worse than that of dyntick-idle.  Furthermore,
        this parameter effectively disables Turbo Mode on Intel
        CPUs, which can significantly reduce maximum performance.

Idle loop
=========

  idle=poll
    Don't do power saving in the idle loop using HLT, but poll for rescheduling
    event. This will make the CPUs eat a lot more power, but may be useful
    to get slightly better performance in multiprocessor benchmarks. It also
    makes some profiling using performance counters more accurate.
    Please note that on systems with MONITOR/MWAIT support (like Intel EM64T
    CPUs) this option has no performance advantage over the normal idle loop.
    It may also interact badly with hyperthreading.

If a user wants the absolute minimum latency, kernel parameter “idle=poll” can be used to keep the
processors in C0 even when they are idle (the processors will run in a loop when idle, constantly
checking to see if they are needed). If this kernel parameter is used, it should not be necessary to
disable C-states in BIOS (or use the “idle=halt” kernel parameter).

Take care when keeping processors in C0, though--this will increase power usage considerably.
Also, hyperthreading should probably be
disabled, as keeping processors in C0 can interfere with proper operation of logical cores
(hyperthreading). (The hyperthreading hardware works best when it knows when the logical processors
are idle, and it doesn’t know that if processors are kept busy in a loop when they are not running
useful code.)