This bug was fixed in the package linux - 4.15.0-29.31
---------------
linux (4.15.0-29.31) bionic; urgency=medium
* linux: 4.15.0-29.31 -proposed tracker (LP: #1782173)
* [SRU Bionic][Cosmic] kernel panic in ipmi_ssif at msg_done_handler
(LP: #1777716)
- ipmi_ssif: Fix kernel panic at msg_done_handler
* Update to ocxl driver for 18.04.1 (LP: #1775786)
- misc: ocxl: use put_device() instead of device_unregister()
- powerpc: Add TIDR CPU feature for POWER9
- powerpc: Use TIDR CPU feature to control TIDR allocation
- powerpc: use task_pid_nr() for TID allocation
- ocxl: Rename pnv_ocxl_spa_remove_pe to clarify it's action
- ocxl: Expose the thread_id needed for wait on POWER9
- ocxl: Add an IOCTL so userspace knows what OCXL features are available
- ocxl: Document new OCXL IOCTLs
- ocxl: Fix missing unlock on error in afu_ioctl_enable_p9_wait()
* Critical upstream bugfix missing in Ubuntu 18.04 - frequent Xorg crash after
suspend (LP: #1776887)
- ocxl: Document the OCXL_IOCTL_GET_METADATA IOCTL
* Hard LOCKUP observed on stressing Ubuntu 18 04 (LP: #1777194)
- powerpc: use NMI IPI for smp_send_stop
- powerpc: Fix smp_send_stop NMI IPI handling
* IPL: ppc64_cpu --frequency hang with INFO: rcu_sched detected stalls on
CPUs/tasks on w34 and wsbmc016 with 920.1714.20170330n (LP: #1773964)
- rtc: opal: Fix OPAL RTC driver OPAL_BUSY loops
* [Regression] EXT4-fs error (device sda2): ext4_validate_block_bitmap:383:
comm stress-ng: bg 4705: bad block bitmap checksum (LP: #1781709)
- SAUCE: Revert "UBUNTU: SAUCE: ext4: fix ext4_validate_inode_bitmap: comm
stress-ng: Corrupt inode bitmap"
- SAUCE: ext4: check for allocation block validity with block group locked
linux (4.15.0-28.30) bionic; urgency=medium
* linux: 4.15.0-28.30 -proposed tracker (LP: #1781433)
* Cannot set MTU higher than 1500 in Xen instance (LP: #1781413)
- xen-netfront: Fix mismatched rtnl_unlock
- xen-netfront: Update features after registering netdev
linux (4.15.0-27.29) bionic; urgency=medium
* linux: 4.15.0-27.29 -proposed tracker (LP: #1781062)
* [Regression] EXT4-fs error (device sda1): ext4_validate_inode_bitmap:99:
comm stress-ng: Corrupt inode bitmap (LP: #1780137)
- SAUCE: ext4: fix ext4_validate_inode_bitmap: comm stress-ng: Corrupt inode
bitmap
linux (4.15.0-26.28) bionic; urgency=medium
* linux: 4.15.0-26.28 -proposed tracker (LP: #1780112)
* failure to boot with linux-image-4.15.0-24-generic (LP: #1779827) // Cloud-
init causes potentially huge boot delays with 4.15 kernels (LP: #1780062)
- random: Make getrandom() ready earlier
linux (4.15.0-25.27) bionic; urgency=medium
* linux: 4.15.0-25.27 -proposed tracker (LP: #1779354)
* hisi_sas_v3_hw: internal task abort: timeout and not done. (LP: #1777736)
- scsi: hisi_sas: Update a couple of register settings for v3 hw
* hisi_sas: Add missing PHY spinlock init (LP: #1777734)
- scsi: hisi_sas: Add missing PHY spinlock init
* hisi_sas: improve read performance by pre-allocating slot DMA buffers
(LP: #1777727)
- scsi: hisi_sas: use dma_zalloc_coherent()
- scsi: hisi_sas: Use dmam_alloc_coherent()
- scsi: hisi_sas: Pre-allocate slot DMA buffers
* hisi_sas: Failures during host reset (LP: #1777696)
- scsi: hisi_sas: Only process broadcast change in phy_bcast_v3_hw()
- scsi: hisi_sas: Fix the conflict between dev gone and host reset
- scsi: hisi_sas: Adjust task reject period during host reset
- scsi: hisi_sas: Add a flag to filter PHY events during reset
- scsi: hisi_sas: Release all remaining resources in clear nexus ha
* Fake SAS addresses for SATA disks on HiSilicon D05 are non-unique
(LP: #1776750)
- scsi: hisi_sas: make SAS address of SATA disks unique
* Vcs-Git header on bionic linux source package points to zesty git tree
(LP: #1766055)
- [Packaging]: Update Vcs-Git
* large KVM instances run out of IRQ routes (LP: #1778261)
- SAUCE: kvm -- increase KVM_MAX_IRQ_ROUTES to 2048 on x86
-- Stefan Bader <stefan.ba...@canonical.com> Tue, 17 Jul 2018 10:57:50
+0200
** Changed in: linux (Ubuntu)
Status: In Progress => Fix Released
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https://bugs.launchpad.net/bugs/1770231
Title:
Expose arm64 CPU topology to userspace
Status in linux package in Ubuntu:
Fix Released
Status in linux source package in Bionic:
Fix Released
Bug description:
[Impact]
Applications, particularly those in the HPC domain (e.g. openmpi), can be
optimized for the processor and cache topology. However, the ARM CPU topology
isn't correctly exposed to userspace. The kernel's scheduler also uses this
information to optimize task placement.
[Fix]
The ACPI 6.2 specification introduced a Processor Properties Topology Table
(PPTT). This is what ARM server vendors are using to expose their topology. The
linux kernel needs support for parsing this table, and exposing the parsed
topology to userspace.
[Test Case]
A HiSilicon D06 without the fix. Note that it thinks I'm on a 24-socket
system with 4 cores each. I'm not. I'm on a 2 socket system w/ 48 cores each.
An HPC app that optimized for this (bogus) topology would therefore suffer a
performance penalty.
ubuntu@d06-1:~$ lscpu
Architecture: aarch64
Byte Order: Little Endian
CPU(s): 96
On-line CPU(s) list: 0-95
Thread(s) per core: 1
Core(s) per socket: 4
Socket(s): 24
NUMA node(s): 4
Vendor ID: 0x48
Model: 0
Stepping: 0x0
BogoMIPS: 200.00
NUMA node0 CPU(s): 0-23
NUMA node1 CPU(s): 24-47
NUMA node2 CPU(s): 48-71
NUMA node3 CPU(s): 72-95
Flags: fp asimd evtstrm aes pmull sha1 sha2 crc32 atomics cpuid
asimdrdm dcpop
With the fix (and this is correct):
ubuntu@d06-1:~$ lscpu
Architecture: aarch64
Byte Order: Little Endian
CPU(s): 96
On-line CPU(s) list: 0-95
Thread(s) per core: 1
Core(s) per socket: 48
Socket(s): 2
NUMA node(s): 4
Vendor ID: 0x48
Model: 0
Stepping: 0x0
BogoMIPS: 200.00
L1d cache: 64K
L1i cache: 64K
L2 cache: 512K
L3 cache: 32768K
NUMA node0 CPU(s): 0-23
NUMA node1 CPU(s): 24-47
NUMA node2 CPU(s): 48-71
NUMA node3 CPU(s): 72-95
Flags: fp asimd evtstrm aes pmull sha1 sha2 crc32 atomics cpuid
asimdrdm dcpop
[Regression Risk]
Here's a patch-by patch risk analysis of the changeset:
0001-ACPICA-ACPI-6.2-Additional-PPTT-flags.patch
Just adds new #defines. No functional change.
0002-drivers-base-cacheinfo-move-cache_setup_of_node.patch
Moves code down in a file. No functional change. (I double-checked that the
moved code is the same).
0003-drivers-base-cacheinfo-setup-DT-cache-properties-ear.patch
The code this touches is all #ifdef CONFIG_OF, which only applies to the ARM
& Power ports of Ubuntu. I've tested on arm64 and regression tested on ppc64el
(POWER9). POWER booted fine, and there was no change to lscpu output.
0004-cacheinfo-rename-of_node-to-fw_token.patch
Renames a variable, and changes it's type from "struct device_node *" to
"void *". No functional change.
0005-arm64-acpi-Create-arch-specific-cpu-to-acpi-id-helpe.patch
Adds a new function (but doesn't use it yet).
0006-ACPI-PPTT-Add-Processor-Properties-Topology-Table-pa.patch
Adds new code that isn't called yet.
0007-UBUNTU-Config-CONFIG_ACPI_PPTT-y.patch
Configures on the new code.
0008-ACPI-Enable-PPTT-support-on-ARM64.patch
Kconfig/Makefile bits for the new code.
0009-drivers-base-cacheinfo-Add-support-for-ACPI-based-fi.patch
Finally, we call the new code during initialization, so let's go back and
look at that code. The first thing it does is to check for the presence of a
PPTT table before proceeding, so the regression risk to systems *without* a
PPTT table is negligible. The PPTT table was introduced in the ACPI 6.2
specification, which was released in May 2017. Regression risk should therefore
be restricted to systems manufactured (or firmware updated) after that time
that happened to include a PPTT table. I don't know of anyone other than ARM
licensees doing this - but it's possible there are others. And, it's possible
that there's a table out there that tickles a bug in the parsing code. Should
that be the case, a hotfix would be to use an initrd to override/strip[*] the
PPTT from the XSDT table until a suitable fix is put in place.
0010-arm64-Add-support-for-ACPI-based-firmware-tables.patch
0011-arm64-topology-rename-cluster_id.patch
0012-arm64-topology-enable-ACPI-PPTT-based-CPU-topology.patch
These patches only touch arm64 code. I explicitly tested on an arm64 server.
0013-ACPI-Add-PPTT-to-injectable-table-list.patch
Allows users to override the PPTT table. No change to default behavior.
0014-arm64-topology-divorce-MC-scheduling-domain-from-cor.patch
Only touches arm64 code. I explicitly tested on an arm64 server.
[*]
https://www.kernel.org/doc/Documentation/acpi/initrd_table_override.txt
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