kernel-packages team mailing list archive

Thread
Date

[Bug 1557690] [NEW] s390/kconfig: CONFIG_NUMA without CONFIG_NUMA_EMU does not make any sense on s390x

To: kernel-packages@xxxxxxxxxxxxxxxxxxx
From: Launchpad Bug Tracker <1557690@xxxxxxxxxxxxxxxxxx>
Date: Tue, 15 Mar 2016 18:03:01 -0000
Reply-to: Bug 1557690 <1557690@xxxxxxxxxxxxxxxxxx>
Sender: bounces@xxxxxxxxxxxxx

You have been subscribed to a public bug:

== Comment: #0 - Hendrik Brueckner - 2016-03-15 06:33:03 ==
For NUMA, ensure the setting of these kernel configuration for s390x:

# CONFIG_NUMA_BALANCING_DEFAULT_ENABLED is not set
CONFIG_NUMA_EMU=y
CONFIG_EMU_SIZE=0x10000000


CONFIG_NUMA without CONFIG_NUMA_EMU does not make any sense. s390 does not provide hardware topology information. However, we do support fake NUMA to improve performance issues seen with very large memory configurations. Therefore, CONFIG_NUMA_EMU has to be enabled.

Given that we only support fake NUMA
CONFIG_NUMA_BALANCING_DEFAULT_ENABLED should be disabled, since it moves
pages without any benefit but costs additional cpu cycles.

** Affects: linux (Ubuntu)
     Importance: Undecided
     Assignee: Andy Whitcroft (apw)
         Status: New


** Tags: architecture-s39064 bugnameltc-139034 severity-critical targetmilestone-inin1604
-- 
s390/kconfig: CONFIG_NUMA without CONFIG_NUMA_EMU does not make any sense on s390x
https://bugs.launchpad.net/bugs/1557690
You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu.