linux_dsm_epyc7002/arch
Andreas Herrmann 5a925b4282 x86, sched: Workaround broken sched domain creation for AMD Magny-Cours
Current sched domain creation code can't handle multi-node processors.
When switching to power_savings scheduling errors show up and
system might hang later on (due to broken sched domain hierarchy):

  # echo 0  >> /sys/devices/system/cpu/sched_mc_power_savings
  CPU0 attaching sched-domain:
   domain 0: span 0-5 level MC
    groups: 0 1 2 3 4 5
    domain 1: span 0-23 level NODE
     groups: 0-5 6-11 18-23 12-17
  ...
  # echo 1  >> /sys/devices/system/cpu/sched_mc_power_savings
  CPU0 attaching sched-domain:
   domain 0: span 0-11 level MC
    groups: 0 1 2 3 4 5 6 7 8 9 10 11
  ERROR: parent span is not a superset of domain->span
    domain 1: span 0-5 level CPU
  ERROR: domain->groups does not contain CPU0
     groups: 6-11 (__cpu_power = 12288)
  ERROR: groups don't span domain->span
     domain 2: span 0-23 level NODE
      groups:
  ERROR: domain->cpu_power not set

  ERROR: groups don't span domain->span
  ...

Fixing all aspects of power-savings scheduling for Magny-Cours needs
some larger changes in the sched domain creation code.

As a short-term and temporary workaround avoid the problems by
extending "the worst possible hack" ;-(
and always use llc_shared_map on AMD Magny-Cours when MC domain span
is calculated.

With this I get:

  # echo 1  >> /sys/devices/system/cpu/sched_mc_power_savings
  CPU0 attaching sched-domain:
   domain 0: span 0-5 level MC
    groups: 0 1 2 3 4 5
    domain 1: span 0-5 level CPU
     groups: 0-5 (__cpu_power = 6144)
     domain 2: span 0-23 level NODE
      groups: 0-5 (__cpu_power = 6144) 6-11 (__cpu_power = 6144) 18-23 (__cpu_power = 6144) 12-17 (__cpu_power = 6144)
  ...

I.e. no errors during sched domain creation, no system hangs, and also
mc_power_savings scheduling works to a certain extend.

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-09-03 15:10:14 -07:00
..
alpha mm: Pass virtual address to [__]p{te,ud,md}_free_tlb() 2009-07-27 12:10:38 -07:00
arm ARM: 5673/1: U300 fix initsection compile warning 2009-08-15 15:36:52 +01:00
avr32 mm: Pass virtual address to [__]p{te,ud,md}_free_tlb() 2009-07-27 12:10:38 -07:00
blackfin blackfin: fix wrong CTS inversion 2009-07-20 16:38:44 -07:00
cris mm: Pass virtual address to [__]p{te,ud,md}_free_tlb() 2009-07-27 12:10:38 -07:00
frv mm: Pass virtual address to [__]p{te,ud,md}_free_tlb() 2009-07-27 12:10:38 -07:00
h8300 sched: INIT_PREEMPT_COUNT 2009-07-10 14:24:05 -07:00
ia64 arch/ia64/kernel/iosapic: missing test after ioremap() 2009-08-11 14:52:11 -07:00
m32r mm: Pass virtual address to [__]p{te,ud,md}_free_tlb() 2009-07-27 12:10:38 -07:00
m68k mm: Pass virtual address to [__]p{te,ud,md}_free_tlb() 2009-07-27 12:10:38 -07:00
m68knommu Remove multiple KERN_ prefixes from printk formats 2009-07-08 10:30:03 -07:00
microblaze microblaze: Update Microblaze defconfigs 2009-08-18 11:05:11 +02:00
mips Merge branch 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-linus 2009-08-17 13:39:52 -07:00
mn10300 MN10300: includecheck fix: mn10300, pci.h 2009-08-10 08:54:27 -07:00
parisc parisc: Set correct bit in protection flags 2009-08-02 12:36:05 +02:00
powerpc Merge branch 'perfcounters-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-08-10 11:48:51 -07:00
s390 Merge branch 'kvm-updates/2.6.31' of git://git.kernel.org/pub/scm/virt/kvm/kvm 2009-08-09 14:58:21 -07:00
sh sh: sh7724 ddr self-refresh changes 2009-08-15 12:58:50 +09:00
sparc percpu, sparc64: fix sparse possible cpu map handling 2009-08-14 13:20:53 +09:00
um mm: Pass virtual address to [__]p{te,ud,md}_free_tlb() 2009-07-27 12:10:38 -07:00
x86 x86, sched: Workaround broken sched domain creation for AMD Magny-Cours 2009-09-03 15:10:14 -07:00
xtensa mm: Pass virtual address to [__]p{te,ud,md}_free_tlb() 2009-07-27 12:10:38 -07:00
.gitignore
Kconfig gcov: add gcov profiling infrastructure 2009-06-18 13:03:57 -07:00