** Description changed: [Impact] We've found a bug on some Apollo Lake system makes it runs very slow. + From upstream it is caused by following reason: + + "Monitored cached line may not wake up from mwait on certain Goldmont + based CPUs. This patch will avoid calling current_set_polling_and_test() + and thereby not set the TIF_ flag. The result is that we'll always send + IPIs for wakeups." [Fix] Upstream already provided a workaround[1] to fix this problem. This patches haven't been merged in latest(v4.7) release but already in linux-next. To fix this issue in Xenial it also needs another commit introduces macros use in the workaround: commit 970442c599b22ccd644ebfe94d1d303bf6f87c05 Author: Dave Hansen <[email protected]> Date: Thu Jun 2 17:19:27 2016 -0700 - x86/cpu/intel: Introduce macros for Intel family numbers + x86/cpu/intel: Introduce macros for Intel family numbers This workaround checks CPU families and certain features, so no further regressions is expected [1]: https://lkml.org/lkml/2016/7/6/469
-- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1606147 Title: [APL][SAUCE] System works slowly due to a monitor bug To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1606147/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
