[lkml]   [2009]   [Nov]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
Subjectx86/NUMA: Reason for ignoring too small NUMA nodes?
Hi Andi,

while experimenting with a system with a memory-less NUMA node I
stumbled upon code in the Linux kernel which ignores nodes containing
less than a certain amount of RAM, obviously to fix systems with a buggy
Can you elaborate on this? What kind of incorrect entry have you seen?
To correctly map the memory less node I did a patch to accept at least
nodes with exactly zero bytes of memory (read: no SRAT memory entry),
was this special condition also present in the buggy machines?
Another comments reads:
* Don't confuse VM with a node that doesn't have the
* minimum amount of memory:
Is that still a valid statement? How can the VM get confused by a node
with already exhausted memory resources?
(found in arch/x86/mm/{srat,numa}_64.c)

I'd be grateful for some hints!


Andre Przywara
AMD-Operating System Research Center (OSRC), Dresden, Germany
Tel: +49 351 448 3567 12
----to satisfy European Law for business letters:
Advanced Micro Devices GmbH
Karl-Hammerschmidt-Str. 34, 85609 Dornach b. Muenchen
Geschaeftsfuehrer: Andrew Bowd; Thomas M. McCoy; Giuliano Meroni
Sitz: Dornach, Gemeinde Aschheim, Landkreis Muenchen
Registergericht Muenchen, HRB Nr. 43632

 \ /
  Last update: 2009-11-09 13:31    [W:0.032 / U:1.216 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site