Support workstations with greater than 64 cores

Bug #737124 reported by Brad Figg on 2011-03-17
This bug affects 1 person
Affects Status Importance Assigned to Milestone
linux (Ubuntu)
Brad Figg
Brad Figg
Brad Figg

Bug Description

SRU Justification

Impact: Workstations with greater than 64 cores cannot boot.

Patch Description: Increase CONFIG_NR_CPUS to 256 for the amd64 generic flavour

See: for more information

Brad Figg (brad-figg) on 2011-03-17
Changed in linux (Ubuntu Maverick):
status: New → In Progress
Changed in linux (Ubuntu Natty):
status: New → In Progress
Changed in linux (Ubuntu Maverick):
assignee: nobody → Brad Figg (brad-figg)
Changed in linux (Ubuntu Natty):
assignee: nobody → Brad Figg (brad-figg)
importance: Undecided → Medium
Changed in linux (Ubuntu Maverick):
importance: Undecided → Medium
Launchpad Janitor (janitor) wrote :

This bug was fixed in the package linux - 2.6.38-8.40

linux (2.6.38-8.40) natty; urgency=low

  [ Brad Figg ]

  * [Config] Set CONFIG_NR_CPUS=256 for amd64 generic
    - LP: #737124

  [ Henrik Rydberg ]

  * SAUCE: HID: hid-ntrig: add support for 1b96:0006 model
  * SAUCE: HID: ntrig: fix suspend/resume on recent models

  [ Kees Cook ]

  * [Config] packaging: adjust perms on vmlinuz as well
  * SAUCE: nx-emu: further clarify dmesg reporting
    - LP: #745181

  [ Leann Ogasawara ]

  * rebase to v2.6.38.1
  * [Config] update configs after v2.6.38.1 rebase
  * rebase to v2.6.38.2

  [ Manoj Iyer ]

  * SAUCE: thinkpad-acpi: module autoloading for newer Lenovo ThinkPads.
    - LP: #745217

  [ Tim Gardner ]

  * SAUCE: INR_OPEN=4096
    - LP: #663090

  [ Upstream Kernel Changes ]

  * (drop after v2.6.38) HID: ntrig don't dereference unclaimed hidinput
  * (drop after v2.6.38) HID: ntrig: apply NO_INIT_REPORTS quirk
  * (drop after v2.6.38) HID: hid-ntrig: init settle and mode check
  * eeepc-wmi: add hotplug code for Eeepc 1000H
  * eeepc-wmi: serialize access to wmi method
  * eeepc-wmi: return proper error code in eeepc_rfkill_set()
  * eeepc-wmi: add an helper using simple return codes
  * eeepc-wmi: add hibernate/resume callbacks
  * eeepc-wmi: switch to platform_create_bundle()
  * eeepc-wmi: reorder defines
  * eeepc-wmi: use the presence bit correctly
  * eeepc-wmi: add camera and card reader support
  * eeepc-wmi: add wimax support
  * eeepc-wmi: set the right key code for 0xe9
  * eeepc-wmi: support backlight power (bl_power) attribute
  * eeepc-wmi: respect wireless_hotplug setting
  * eeepc-wmi: real touchpad led device id is 0x001000012
  * eeepc-wmi: comments keymap to clarify the meaning of some keys
  * eeepc-wmi: add touchpad sysfs file
  * eeepc-wmi: reorder device ids

  [ Major Kernel Changes ]

  * rebase from v2.6.38 to v2.6.38.1
    - LP: #735640, #735450
  * rebase from v2.6.38.1 to v2.6.38.2
    - LP: #733780
 -- Leann Ogasawara <email address hidden> Mon, 28 Mar 2011 06:20:13 -0700

Changed in linux (Ubuntu Natty):
status: In Progress → Fix Released
Roland Dreier (roland.dreier) wrote :

I just noticed this change. Two comments:

 - The overhead is not as trivial as bug #706058 seems to imply. If you look at eg <linux/cpumask.h> you see that increasing NR_CPUS above BITS_PER_LONG (ie going over 64) changes the cpumask code, arch/x86/include/asm/spinlock.h uses different code for NR_CPUS >= 256, etc. I think it would be worth it for someone to run some benchmarks and make sure the overhead is tolerable for the common case.

- I don't think the description is accurate -- don't systems with more CPUs still boot, just without being able to use all the CPUs? I know having more kernel variants is painful but it might be a better idea to have a "huge SMP" variant for the tiny fraction of systems Ubuntu is used on that have more than 64 CPUs. (What are the platforms that this is targeted at? are there really workstations with > 64 CPUs? I can only think of server-class HW: 8-socket Nehalem EX (8 sockets, 8 cores, 2 SMT) or 4+ socket Westmere EX (10 cores/socket 2x SMT).

Steve Conklin (sconklin) on 2011-04-14
Changed in linux (Ubuntu Maverick):
status: In Progress → Fix Committed

Accepted linux into maverick-proposed, the package will build now and be available in a few hours. Please test and give feedback here. See for documentation how to enable and use -proposed. Thank you in advance!

Steve Conklin (sconklin) wrote :

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' to 'verification-done'.

See for documentation how to enable and use -proposed. Thank you!

tags: added: verification-needed-maverick
Brad Figg (brad-figg) wrote :

I don't have the HW required to test this. However it is just a config change and the same change was made to natty and caused no issues.

Steve Conklin (sconklin) on 2011-06-14
tags: added: verification-done-maverick
removed: verification-needed-maverick
Launchpad Janitor (janitor) wrote :
Download full text (30.0 KiB)

This bug was fixed in the package linux - 2.6.35-30.54

linux (2.6.35-30.54) maverick-proposed; urgency=low

  [ Brad Figg ]

  * Release Tracking Bug
    - LP: #794114

  [ Upstream Kernel Changes ]

  * Revert "xhci: Fix full speed bInterval encoding."
  * Revert "USB: xhci - also free streams when resetting devices"
  * Revert "USB: xhci - fix math in xhci_get_endpoint_interval()"
  * Revert "USB: xhci - fix unsafe macro definitions"

linux (2.6.35-30.53) maverick-proposed; urgency=low

  [ Upstream Kernel Changes ]

  * xhci: Fix full speed bInterval encoding.
    - LP: #792959

linux (2.6.35-30.52) maverick-proposed; urgency=low

  [ Herton R. Krzesinski ]

  * Release Tracking Bug
    - LP: #790653

  [ Stefan Bader ]

  * Include nls_iso8859-1 for virtual images
    - LP: #732046

  [ Thomas Schlichter ]

  * SAUCE: vesafb: mtrr module parameter is uint, not bool
    - LP: #778043

  [ Tim Gardner ]

  * [Config] Add cachefiles.ko to virtual flavour
    - LP: #770430

  [ Upstream Kernel Changes ]

  * Revert "intel_idle: PCI quirk to prevent Lenovo Ideapad s10-3 boot
    - LP: #772560
  * Revert "TPM: Long default timeout fix"
    - LP: #772560
  * Revert "tpm_tis: Use timeouts returned from TPM"
    - LP: #772560
  * Revert "xen: set max_pfn_mapped to the last pfn mapped"
  * CAN: Use inode instead of kernel address for /proc file, CVE-2010-4565
    - LP: #765007
    - CVE-2010-4565
  * xfs: prevent leaking uninitialized stack memory in FSGEOMETRY_V1,
    - LP: #767740
    - CVE-2011-0711
  * Treat writes as new when holes span across page boundaries,
    - LP: #770483
    - CVE-2011-0463
  * fs/partitions/ldm.c: fix oops caused by corrupted partition table,
    - LP: #771382
    - CVE-2011-1017
  * qla2xxx: Make the FC port capability mutual exclusive.
    - LP: #772560
  * staging: usbip: bugfixes related to kthread conversion
    - LP: #772560
  * staging: usbip: bugfix add number of packets for isochronous frames
    - LP: #772560
  * staging: usbip: bugfix for isochronous packets and optimization
    - LP: #772560
  * staging: hv: Fix GARP not sent after Quick Migration
    - LP: #772560
  * staging: hv: use sync_bitops when interacting with the hypervisor
    - LP: #772560
  * irda: validate peer name and attribute lengths
    - LP: #772560
  * irda: prevent heap corruption on invalid nickname
    - LP: #772560
  * nilfs2: fix data loss in mmap page write for hole blocks
    - LP: #772560
  * ASoC: Explicitly say registerless widgets have no register
    - LP: #772560
  * ALSA: ens1371: fix Creative Ectiva support
    - LP: #772560
  * ROSE: prevent heap corruption with bad facilities
    - LP: #772560
  * Btrfs: Fix uninitialized root flags for subvolumes
    - LP: #772560
  * x86, mtrr, pat: Fix one cpu getting out of sync during resume
    - LP: #772560
  * UBIFS: do not read flash unnecessarily
    - LP: #772560
  * UBIFS: fix oops on error path in read_pnode
    - LP: #772560
  * UBIFS: fix debugging failure in dbg_check_space_info
    - LP: #772560
  * quota: Don't write quota info in dquot_commit()
    - LP: #772560
  * mm: avoid wrapping vm_...

Changed in linux (Ubuntu Maverick):
status: Fix Committed → Fix Released
To post a comment you must log in.
This report contains Public information  Edit
Everyone can see this information.

Other bug subscribers