This bug is awaiting verification that the kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification-needed- zesty' to 'verification-done-zesty'. If the problem still exists, change the tag 'verification-needed-zesty' to 'verification-failed-zesty'.
If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Thank you! ** Tags added: verification-needed-zesty -- 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/1719697 Title: Boot/Installation crash of Ubuntu-16.04.3 HWE kernel on R940 Status in dellserver: In Progress Status in linux package in Ubuntu: In Progress Status in linux source package in Zesty: Fix Committed Bug description: == SRU Justification == Kernel crashes when installation of Ubuntu-16.04.3 with HWE (ISO). Same observation while booting to 4.10.0-28 HWE kerenl of Ubuntu-16.04.3 and 4.10.0-33 HWE as well. Seen only with 4.10 HWE kernels of Ubuntu-16.04.3. 4.4 kernels of Ubuntu-16.04.3 works fine. Daily builds of Ubuntu Server 17.10 works fine. Reducing the core count to <26 cores helps here. Boot & installation of HWE-kernel works fine. This bug was introduced by commit: dc6db24d2476 ("x86/acpi: Set persistent cpuid <-> nodeid mapping when booting") It is resolved by reverting commit dc6db24d2476, which was done in mainline by commit c962cff17df as of v4.11-rc3. There are three additiona commits introduced by the same patch author when commit c962cff17df was submitted. However, it was confirmed that only the single revert is needed to fix this particular bug. Upstream thread: https://lkml.org/lkml/2017/2/20/66 == Fix == commit c962cff17dfa11f4a8227ac16de2b28aea3312e4 Author: Dou Liyang <douly.f...@cn.fujitsu.com> Date: Fri Mar 3 16:02:23 2017 +0800 Revert "x86/acpi: Set persistent cpuid <-> nodeid mapping when booting" == Regression Potential == This is reverting a commit that introduced a bug. This commit has also been reverted upstream. == Test Case == A test kernel was built with this patch and tested by the original bug reporter. The bug reporter states the test kernel resolved the bug. Setup: Dell PowerEdge R940 having 2 socket populated with 28 cores. Impact: This is a boot and installation failure for R940 users having 2 socket x 28 cores. Requesting an SRU for the fix. Steps: 1. Setup a Dell PowerEdge R940 with 28 cores CPUs on 2 sockets. 2. Start installation of Ubuntu-16.04.3 with HWE kernel. 3. Observe the screen remains blank. Console logs indicate kernel crash. Additional Info: * Seen only with 4.10 HWE kernels of Ubuntu-16.04.3. 4.4 kernels of Ubuntu-16.04.3 works fine. Daily builds of Ubuntu Server 17.10 works fine. * Reducing the core count to <26 cores helps here. Boot & installation of HWE-kernel works fine. * Attaching the console log and acpidump from the setup. * Patch causing this failure: https://github.com/torvalds/linux/commit/dc6db24d2476cd09c0ecf2b8d80313539f737a89 x86/acpi: Set persistent cpuid <-> nodeid mapping when booting * Fix patch series: https://lkml.org/lkml/2017/2/20/66 Revert "x86/acpi: Set persistent cpuid <-> nodeid mapping when booting" https://github.com/torvalds/linux/commit/c962cff17dfa11f4a8227ac16de2b28aea3312e4#diff-6bd7ef719bca1a2a56b9ebf4bd0bd88d Revert"x86/acpi: Enable MADT APIs to return disabled apicids" https://github.com/torvalds/linux/commit/09c3f2bd5c7e5f18687663acb6adc6b167484ca5 acpi/processor: Implement DEVICE operator for processor enumeration https://github.com/torvalds/linux/commit/8c8cb30f49b86333d8e036e1945cf1a78c03577e acpi/processor: Check for duplicate processor ids at hotplug time https://github.com/torvalds/linux/commit/a77d6cd968497792e072b74dff45b891ba778ddb To manage notifications about this bug go to: https://bugs.launchpad.net/dellserver/+bug/1719697/+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