Slackware64-current ChangeLog (2021-10-23)

Sat Oct 23 18:57:30 UTC 2021

  • ap/itstool-2.0.7-x86_64-2.txz
    Rebuilt with PYTHON=/usr/bin/python3. Thanks to USUARIONUEVO.
  • testing/packages/linux-5.14.x/kernel-source-5.14.14-noarch-2.txz
    These kernels enable CONFIG_PREEMPT=y and CONFIG_PREEMPT_DYNAMIC=y allowing
    the kernel preemption model to be specified on the kernel command line
    with one of these options: preempt=none, preempt=voluntary, and preempt=full.
    Since there is no .config option to set a default, and the default in the
    kernel sources is “full” (which is probably not a good default), the
    kernel-source.SlackBuild has been modified to add support for an environment
    variable CONFIG_PREEMPT_DEFAULT_MODE which can be set to none, voluntary, or
    full to set the default kernel preemption model when a command line option
    is not provided. These kernels have been built with a preemption model of
    “none” (presumably the safest choice which will behave like the kernels we
    have shipped before.) The runtime overhead on 64-bit should be negligible.
    On 32-bit we lack support for HAVE_STATIC_CALL_INLINE, so spinlocks and
    mutexes will have to be approached through a trampoline, adding a very small
    amount of overhead. I feel this is probably worth it in order to have the
    option to run a kernel with voluntary or full preemption, especially for
    gaming or desktop purposes. The reduction in input lag with these modes is
    actually quite noticable.
    To check the current preemption model, you may use debugfs:
    mount -t debugfs none /sys/kernel/debug
    cat /sys/kernel/debug/sched/preempt
    (none) voluntary full
    You may change to a different preemption model on the fly once debugfs is
    mounted:
    echo voluntary > /sys/kernel/debug/sched/preempt
    cat /sys/kernel/debug/sched/preempt
    none (voluntary) full
    Thanks to Daedra.
    -DRM_I810 n
    -INLINE_READ_UNLOCK y
    -INLINE_READ_UNLOCK_IRQ y
    -INLINE_SPIN_UNLOCK_IRQ y
    -INLINE_WRITE_UNLOCK y
    -INLINE_WRITE_UNLOCK_IRQ y
    PREEMPT n → y
    PREEMPT_VOLUNTARY y → n
    +CEC_GPIO n
    +DEBUG_PREEMPT y
    +PREEMPTION y
    +PREEMPT_COUNT y
    +PREEMPT_DYNAMIC y
    +PREEMPT_RCU y
    +PREEMPT_TRACER n
    +RCU_BOOST n
    +TASKS_RCU y
    +UNINLINE_SPIN_UNLOCK y
  • news/2021/10/23/slackware64-current-changelog.txt
  • Last modified: 6 weeks ago
  • by Giuseppe Di Terlizzi