Public bug reported: Hi team,,
I have a customer, who tried to install Xenial or upgrade to 4.4 kernel with Trusty on our cloud platform(qemu 1.5.3), reports a defect. he complains that only one cpu is successfully detected, other cpus is disabled if he used 4.4 kernel. I tried to bisect Xenial kernel tree, and found that this bug was introduced by the following commit. commit 31c2013e4ea2e594522980acc3d20e88664b19f1 Author: Thomas Gleixner <t...@linutronix.de> Date: Mon Feb 22 22:19:15 2016 +0000 x86/topology: Create logical package id BugLink: http://bugs.launchpad.net/bugs/1397880 For per package oriented services we must be able to rely on the number of CPU packages to be within bounds. Create a tracking facility, which - calculates the number of possible packages depending on nr_cpu_ids after boot - makes sure that the package id is within the number of possible packages. If the apic id is outside we map it to a logical package id if there is enough space available. Provide interfaces for drivers to query the mapping and do translations from physcial to logical ids. and then I backported 7b0501b1e7cddd32b265178e32d332bdfbb532d4 from Linus tree to Xenial kernel, the issue goes away, so could we consider to backport it to xenial kernel tree to solve this issue in next release? >From 7b0501b1e7cddd32b265178e32d332bdfbb532d4 Mon Sep 17 00:00:00 2001 From: Jiri Olsa <jo...@redhat.com> Date: Mon, 15 Aug 2016 12:17:00 +0200 Subject: [PATCH] x86/smp: Fix __max_logical_packages value setup Frank reported kernel panic when he disabled several cores in BIOS via following option: Thanks Wei ** Affects: linux (Ubuntu) Importance: Undecided Status: Fix Released ** Affects: linux (Ubuntu Xenial) Importance: Undecided Assignee: Tim Gardner (timg-tpi) Status: In Progress ** Also affects: linux (Ubuntu Xenial) Importance: Undecided Status: New -- 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/1648088 Title: linux - Memory Bandwidth Monitoring regression Status in linux package in Ubuntu: Fix Released Status in linux source package in Xenial: In Progress Bug description: Hi team,, I have a customer, who tried to install Xenial or upgrade to 4.4 kernel with Trusty on our cloud platform(qemu 1.5.3), reports a defect. he complains that only one cpu is successfully detected, other cpus is disabled if he used 4.4 kernel. I tried to bisect Xenial kernel tree, and found that this bug was introduced by the following commit. commit 31c2013e4ea2e594522980acc3d20e88664b19f1 Author: Thomas Gleixner <t...@linutronix.de> Date: Mon Feb 22 22:19:15 2016 +0000 x86/topology: Create logical package id BugLink: http://bugs.launchpad.net/bugs/1397880 For per package oriented services we must be able to rely on the number of CPU packages to be within bounds. Create a tracking facility, which - calculates the number of possible packages depending on nr_cpu_ids after boot - makes sure that the package id is within the number of possible packages. If the apic id is outside we map it to a logical package id if there is enough space available. Provide interfaces for drivers to query the mapping and do translations from physcial to logical ids. and then I backported 7b0501b1e7cddd32b265178e32d332bdfbb532d4 from Linus tree to Xenial kernel, the issue goes away, so could we consider to backport it to xenial kernel tree to solve this issue in next release? From 7b0501b1e7cddd32b265178e32d332bdfbb532d4 Mon Sep 17 00:00:00 2001 From: Jiri Olsa <jo...@redhat.com> Date: Mon, 15 Aug 2016 12:17:00 +0200 Subject: [PATCH] x86/smp: Fix __max_logical_packages value setup Frank reported kernel panic when he disabled several cores in BIOS via following option: Thanks Wei To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1648088/+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