BL495C G6

[flirek]

we got 2 new blades destined to be LAMP machines. after instalation i look in dmesg and find that log say "No NUMA configuration found".
kernel is 2.6.30.3/vanilla

compared to other blades with AMD procesor i found that SRAT tables are missing in ACPI data in firmware ROM.
will this be fixed soon?

[Matti_Kurkela]

NUMA = Non-Uniform Memory Architecture, e.g. some region of memory is somehow "better" than others for a particular processor.

If the memory architecture of this blade is completely uniform (all memory performs equally), then there will be no need for any NUMA configuration data.

NUMA allows large systems to be used more efficiently, as the OS can be made aware of the properties of the hardware. But it can also be a liability, if the OS and application processing algorithms cannot adapt to the limitations of the hardware. A non-NUMA system can do anything equally well: its performace is simpler to predict.

A NUMA system may require more tuning and tweaking to get the absolute best performance than an equivalent non-NUMA system, although the SRAT ACPI tables and NUMA features in the OS are aimed to minimize the need of manual tuning.

MK