[Kernel-packages] [Bug 1854059] Re: [UBUNTU] kernel: cpu idle time calculation
Updating eoan entry to Fix Released, since patch "s390/idle: fix cpu idle time calculation" with commit "a700d7b0" is in eoan master. It's available with the kernels: Ubuntu-5.3.0-24.26 Ubuntu-5.3.0-25.27 Ubuntu-5.3.0-26.28 Ubuntu-5.3.0-27.29 and we are at "linux-generic | 5.3.0.26.30 | eoan-updates| s390x" as of today. ** Changed in: linux (Ubuntu Eoan) Status: Fix Committed => Fix Released -- 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/1854059 Title: [UBUNTU] kernel: cpu idle time calculation Status in Ubuntu on IBM z Systems: Fix Released Status in linux package in Ubuntu: Fix Released Status in linux source package in Bionic: Fix Released Status in linux source package in Disco: Fix Released Status in linux source package in Eoan: Fix Released Bug description: Description: kernel: cpu idle time calculation Symptom: The cpu idle time reported within /proc/stat as well as in /sys/devices/system/cpu/cpuX/idle_time_us sometimes may show incorrect values. Problem: The kernel tries to figure out when a cpu entered idle by accessing its per-cpu data structure. There is an ordering problem: if a remote cpu has an idle_enter value which is not zero, and an idle_exit value which is zero, it is assumed it is idle since "now". The "now" timestamp however is taken before the idle_enter value is read. This in turn means that "now" can be smaller than idle_enter of the remote cpu. Unconditionally subtracting idle_enter from "now" can thus lead to a negative value (aka large unsigned value). Solution: Move the get_tod_clock() invocation. Upstream-ID: https://github.com/torvalds/linux/commit/3d7efa4edd07be5c5c3ffa95ba63e97e070e1f3f Patch tagged as "stable". Tracking the integration of this patch in the relevant distros.. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-z-systems/+bug/1854059/+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
[Kernel-packages] [Bug 1854059] Re: [UBUNTU] kernel: cpu idle time calculation
Updating disco entry to Fix Released, since patch "s390/idle: fix cpu idle time calculation" with commit "b3ff8122" is in disco master. It's available with the kernels: Ubuntu-5.0.0-38.41 Ubuntu-5.0.0-39.43 and we are at "linux-generic | 5.0.0.38.40 | disco-updates | s390x" as of today. ** Changed in: linux (Ubuntu Disco) Status: Fix Committed => Fix Released ** Changed in: ubuntu-z-systems Status: Fix Committed => Fix Released -- 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/1854059 Title: [UBUNTU] kernel: cpu idle time calculation Status in Ubuntu on IBM z Systems: Fix Released Status in linux package in Ubuntu: Fix Released Status in linux source package in Bionic: Fix Released Status in linux source package in Disco: Fix Released Status in linux source package in Eoan: Fix Released Bug description: Description: kernel: cpu idle time calculation Symptom: The cpu idle time reported within /proc/stat as well as in /sys/devices/system/cpu/cpuX/idle_time_us sometimes may show incorrect values. Problem: The kernel tries to figure out when a cpu entered idle by accessing its per-cpu data structure. There is an ordering problem: if a remote cpu has an idle_enter value which is not zero, and an idle_exit value which is zero, it is assumed it is idle since "now". The "now" timestamp however is taken before the idle_enter value is read. This in turn means that "now" can be smaller than idle_enter of the remote cpu. Unconditionally subtracting idle_enter from "now" can thus lead to a negative value (aka large unsigned value). Solution: Move the get_tod_clock() invocation. Upstream-ID: https://github.com/torvalds/linux/commit/3d7efa4edd07be5c5c3ffa95ba63e97e070e1f3f Patch tagged as "stable". Tracking the integration of this patch in the relevant distros.. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-z-systems/+bug/1854059/+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
[Kernel-packages] [Bug 1854059] Re: [UBUNTU] kernel: cpu idle time calculation
Updating bionic entry to Fix Released, since patch "s390/idle: fix cpu idle time calculation" with commit "44ef7df" is in bionic master. It's available with the kernels: Ubuntu-4.15.0-71.80 Ubuntu-4.15.0-72.81 Ubuntu-4.15.0-73.82 Ubuntu-4.15.0-74.84 and we are at "linux-generic | 4.15.0.74.76 | bionic-updates | s390x" as of today. ** Changed in: linux (Ubuntu Bionic) Status: Fix Committed => Fix Released -- 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/1854059 Title: [UBUNTU] kernel: cpu idle time calculation Status in Ubuntu on IBM z Systems: Fix Released Status in linux package in Ubuntu: Fix Released Status in linux source package in Bionic: Fix Released Status in linux source package in Disco: Fix Released Status in linux source package in Eoan: Fix Released Bug description: Description: kernel: cpu idle time calculation Symptom: The cpu idle time reported within /proc/stat as well as in /sys/devices/system/cpu/cpuX/idle_time_us sometimes may show incorrect values. Problem: The kernel tries to figure out when a cpu entered idle by accessing its per-cpu data structure. There is an ordering problem: if a remote cpu has an idle_enter value which is not zero, and an idle_exit value which is zero, it is assumed it is idle since "now". The "now" timestamp however is taken before the idle_enter value is read. This in turn means that "now" can be smaller than idle_enter of the remote cpu. Unconditionally subtracting idle_enter from "now" can thus lead to a negative value (aka large unsigned value). Solution: Move the get_tod_clock() invocation. Upstream-ID: https://github.com/torvalds/linux/commit/3d7efa4edd07be5c5c3ffa95ba63e97e070e1f3f Patch tagged as "stable". Tracking the integration of this patch in the relevant distros.. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-z-systems/+bug/1854059/+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
[Kernel-packages] [Bug 1854059] Re: [UBUNTU] kernel: cpu idle time calculation
I'm changing the status of the "linux (Ubuntu)" entry - which represents 'focal' the current release in development - to Fix Released, since patch "s390/idle: fix cpu idle time calculation" with commit ID "3d7efa4" landed in focal with the update of focal's kernel to 5.4 (5.4.0.9.11 as of today). This patch is in: Ubuntu-5.4-5.4.0-10.13 Ubuntu-5.4-5.4.0-11.14 Ubuntu-5.4.0-8.11 Ubuntu-5.4.0-9.12 ** Changed in: linux (Ubuntu) Status: Confirmed => Fix Released -- 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/1854059 Title: [UBUNTU] kernel: cpu idle time calculation Status in Ubuntu on IBM z Systems: Fix Committed Status in linux package in Ubuntu: Fix Released Status in linux source package in Bionic: Fix Committed Status in linux source package in Disco: Fix Committed Status in linux source package in Eoan: Fix Committed Bug description: Description: kernel: cpu idle time calculation Symptom: The cpu idle time reported within /proc/stat as well as in /sys/devices/system/cpu/cpuX/idle_time_us sometimes may show incorrect values. Problem: The kernel tries to figure out when a cpu entered idle by accessing its per-cpu data structure. There is an ordering problem: if a remote cpu has an idle_enter value which is not zero, and an idle_exit value which is zero, it is assumed it is idle since "now". The "now" timestamp however is taken before the idle_enter value is read. This in turn means that "now" can be smaller than idle_enter of the remote cpu. Unconditionally subtracting idle_enter from "now" can thus lead to a negative value (aka large unsigned value). Solution: Move the get_tod_clock() invocation. Upstream-ID: https://github.com/torvalds/linux/commit/3d7efa4edd07be5c5c3ffa95ba63e97e070e1f3f Patch tagged as "stable". Tracking the integration of this patch in the relevant distros.. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-z-systems/+bug/1854059/+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
[Kernel-packages] [Bug 1854059] Re: [UBUNTU] kernel: cpu idle time calculation
Thanks Heiko, I just looked the patch(commit-ID up in the ubuntu master- next git trees of the Ubuntu releases that are in service. In Eoan this patch is already addressed by: LP 1851550: Eoan update: 5.3.9 upstream stable release Hence, adapting the status from LP 1851550 (currently Fix Committed) to the Eoan entry here. In Disco this patch is already addressed by: LP 1853067: Disco update: upstream stable patchset 2019-11-18 Hence, adapting the status from LP 1853067 (currently Fix Committed) to the Disco entry here. In Bionic this patch is already addressed by: LP 1852492: Bionic update: upstream stable patchset 2019-11-13 Hence, adapting the status from LP 1852492 (currently Fix Committed) to the Bionic entry here. In addition, the target kernel for Focus is 5.4; and the patch here got upstream accepted with 5.4, hence changing the Focal entry here to Confirmed. ** Changed in: linux (Ubuntu) Status: Incomplete => Confirmed ** Changed in: linux (Ubuntu Bionic) Status: New => Fix Committed ** Changed in: linux (Ubuntu Disco) Status: New => Fix Committed ** Changed in: linux (Ubuntu Eoan) Status: New => Fix Committed ** Changed in: ubuntu-z-systems Status: Incomplete => Fix Committed -- 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/1854059 Title: [UBUNTU] kernel: cpu idle time calculation Status in Ubuntu on IBM z Systems: Fix Committed Status in linux package in Ubuntu: Confirmed Status in linux source package in Bionic: Fix Committed Status in linux source package in Disco: Fix Committed Status in linux source package in Eoan: Fix Committed Bug description: Description: kernel: cpu idle time calculation Symptom: The cpu idle time reported within /proc/stat as well as in /sys/devices/system/cpu/cpuX/idle_time_us sometimes may show incorrect values. Problem: The kernel tries to figure out when a cpu entered idle by accessing its per-cpu data structure. There is an ordering problem: if a remote cpu has an idle_enter value which is not zero, and an idle_exit value which is zero, it is assumed it is idle since "now". The "now" timestamp however is taken before the idle_enter value is read. This in turn means that "now" can be smaller than idle_enter of the remote cpu. Unconditionally subtracting idle_enter from "now" can thus lead to a negative value (aka large unsigned value). Solution: Move the get_tod_clock() invocation. Upstream-ID: https://github.com/torvalds/linux/commit/3d7efa4edd07be5c5c3ffa95ba63e97e070e1f3f Patch tagged as "stable". Tracking the integration of this patch in the relevant distros.. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-z-systems/+bug/1854059/+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
[Kernel-packages] [Bug 1854059] Re: [UBUNTU] kernel: cpu idle time calculation
** Also affects: linux (Ubuntu Disco) Importance: Undecided Status: New ** Also affects: linux (Ubuntu Eoan) Importance: Undecided Status: New ** Also affects: linux (Ubuntu Bionic) 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/1854059 Title: [UBUNTU] kernel: cpu idle time calculation Status in Ubuntu on IBM z Systems: Fix Committed Status in linux package in Ubuntu: Confirmed Status in linux source package in Bionic: Fix Committed Status in linux source package in Disco: Fix Committed Status in linux source package in Eoan: Fix Committed Bug description: Description: kernel: cpu idle time calculation Symptom: The cpu idle time reported within /proc/stat as well as in /sys/devices/system/cpu/cpuX/idle_time_us sometimes may show incorrect values. Problem: The kernel tries to figure out when a cpu entered idle by accessing its per-cpu data structure. There is an ordering problem: if a remote cpu has an idle_enter value which is not zero, and an idle_exit value which is zero, it is assumed it is idle since "now". The "now" timestamp however is taken before the idle_enter value is read. This in turn means that "now" can be smaller than idle_enter of the remote cpu. Unconditionally subtracting idle_enter from "now" can thus lead to a negative value (aka large unsigned value). Solution: Move the get_tod_clock() invocation. Upstream-ID: https://github.com/torvalds/linux/commit/3d7efa4edd07be5c5c3ffa95ba63e97e070e1f3f Patch tagged as "stable". Tracking the integration of this patch in the relevant distros.. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-z-systems/+bug/1854059/+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
[Kernel-packages] [Bug 1854059] Re: [UBUNTU] kernel: cpu idle time calculation
Since I see 1910 as targetmilestone in the tags I assume that issue occured on disco's kernel 5.0. But please can you let us know is bionic' 4.15 is affected, too - or Eoan/5.3 and higher? Thx ** Also affects: ubuntu-z-systems Importance: Undecided Status: New ** Changed in: linux (Ubuntu) Importance: Undecided => Medium ** Changed in: ubuntu-z-systems Importance: Undecided => Medium ** Changed in: ubuntu-z-systems Assignee: (unassigned) => Frank Heimes (fheimes) ** Changed in: linux (Ubuntu) Status: New => Incomplete ** Changed in: ubuntu-z-systems Status: New => Incomplete -- 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/1854059 Title: [UBUNTU] kernel: cpu idle time calculation Status in Ubuntu on IBM z Systems: Incomplete Status in linux package in Ubuntu: Incomplete Bug description: Description: kernel: cpu idle time calculation Symptom: The cpu idle time reported within /proc/stat as well as in /sys/devices/system/cpu/cpuX/idle_time_us sometimes may show incorrect values. Problem: The kernel tries to figure out when a cpu entered idle by accessing its per-cpu data structure. There is an ordering problem: if a remote cpu has an idle_enter value which is not zero, and an idle_exit value which is zero, it is assumed it is idle since "now". The "now" timestamp however is taken before the idle_enter value is read. This in turn means that "now" can be smaller than idle_enter of the remote cpu. Unconditionally subtracting idle_enter from "now" can thus lead to a negative value (aka large unsigned value). Solution: Move the get_tod_clock() invocation. Upstream-ID: https://github.com/torvalds/linux/commit/3d7efa4edd07be5c5c3ffa95ba63e97e070e1f3f Patch tagged as "stable". Tracking the integration of this patch in the relevant distros.. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-z-systems/+bug/1854059/+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
