------- Comment From ranjs...@in.ibm.com 2017-05-04 09:01 EDT------- (In reply to comment #10) > I built a test kernel with these four patches. The test kernel can be > downloaded from: > http://kernel.ubuntu.com/~jsalisbury/lp1685792/
I have verified that the CPU-Hotplug functions correctly on this kernel on a machine booted with upstream skiboot. It can be observed that the CPUs were put into stop1 on a hotplug. ============================================================ root@ubuntu:/home/ego# dmesg | grep -i "deep" | grep stop [ 0.702036] cpuidle-powernv: Deepest stop: psscr = 0x0000000000300331,mask=0x00000000003003ff [ 0.702185] cpuidle-powernv: Requested Level (RL) value of first deep stop = 0xf ============================================================ -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1685792 Title: Offlined CPUs of a core fail to come up online on POWER9 DD1 (Ubuntu 17.04) Status in The Ubuntu-power-systems project: New Status in linux package in Ubuntu: New Bug description: == Comment: #0 - Ranjal G. Shenoy <ranjs...@in.ibm.com> - 2017-04-20 08:29:13 == Power9 DD1 has a hardware issue due to which in core whose all threads are offlined , when any of the CPUs are onlined, they come online with an incorrect PACA thereby resulting in a crash. The following fixes sent upstream need to applied to the 17.04 kernel to get CPU-Hotplug working correctly on a Power9 DD1 system. 1) powerpc/linux.git next, commit a7cd88da9704 ("powernv: Move CPU- Offline idle state invocation from smp.c to idle.c"). 2) powerpc/linux.git next, the commit 900612315788 ("powerpc/powernv/smp: Add busy-wait loop as fall back for CPU- Hotplug"). 3) powerpc/linux.git, commit f3b3f28493d932 ("powerpc/powernv/idle: Don't override default/deepest directly in kernel"). 4) powerpc/linux.git next, commit 17ed4c8f81da ("powerpc/powernv: Recover correct PACA on wakeup from a stop on P9 DD1"). These patches have been backported onto the 17.04 Kernel tagged Ubuntu-4.10.0-19.21. == Comment: #1 - Ranjal G. Shenoy <ranjs...@in.ibm.com> - 2017-04-20 08:29:54 == == Comment: #2 - Ranjal G. Shenoy <ranjs...@in.ibm.com> - 2017-04-20 08:30:37 == == Comment: #3 - Ranjal G. Shenoy <ranjs...@in.ibm.com> - 2017-04-20 08:31:15 == To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-power-systems/+bug/1685792/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
