Running this also works (disabling intel_idle.max_cstate=1 on grub). #!/bin/sh
#title: c6off+c7on.sh #description: Disables all C6 and enables all C7 core states for Baytrail CPUs #author: Wolfgang Reimer <linuxball (at) gmail.com> #date: 20190616 #version: 2.0 #usage: sudo <path>/c6off+c7on.sh #notes: Intended as test script to verify whether erratum VLP52 (see # [1]) is the root cause for kernel bug 109051 (see [2]). In order # for this to work you must _NOT_ use boot parameter # intel_idle.max_cstate=<number>. # # [1] http://www.intel.com/content/dam/www/public/us/en/documents/specification-updates/pentium-n3520-j2850-celeron-n2920-n2820-n2815-n2806-j1850-j1750-spec-update.pdf # [2] https://bugzilla.kernel.org/show_bug.cgi?id=109051 # Disable ($1 == 1) or enable ($1 == 0) core state, if not yet done. disable() { local action read disabled <disable test "$disabled" = $1 && return echo $1 >disable || return action=ENABLED; test "$1" = 0 || action=DISABLED printf "%-8s state %7s for %s.\n" $action "$name" $cpu } # Iterate through each core state and for Baytrail (BYT) disable all C6 # and enable all C7 states. cd /sys/devices/system/cpu for cpu in cpu[0-9]*; do for dir in $cpu/cpuidle/state*; do cd "$dir" read name <name case $name in C6*) disable 1;; C7*) disable 0;; esac cd ../../.. done done ** Bug watch added: Linux Kernel Bug Tracker #109051 https://bugzilla.kernel.org/show_bug.cgi?id=109051 -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1833169 Title: intel_max_cstate is needed with baytrail to aviod hangups To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1833169/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
