lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [thread-next>] [day] [month] [year] [list]
Date:	Mon, 9 Nov 2009 13:27:15 +0100
From:	Andre Przywara <andre.przywara@....com>
To:	Andi Kleen <andi@...stfloor.org>
CC:	Linux-kernel <linux-kernel@...r.kernel.org>
Subject: x86/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 
BIOS.
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!

Thanks,
Andre.

-- 
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

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Powered by blists - more mailing lists