Red Hat Bugzilla – Bug 437167
Need NUMA content in Realtime Tuning Guide
Last modified: 2013-10-23 19:06:58 EDT
Description of problem:
NUMA (Non-Uniform Memory Access) systems can interact badly with realtime
applications by causing unexpected event latencies. We need tuning content that
is specific to dealing with NUMA hardware.
Added the following section to the "Realtime Tuning" chapter, until more info
<title>Non-Uniform Memory Access</title>
Non-Uniform Memory Access (NUMA) is a design used to allocate memory resources
to a specific CPU. This can improve access time and results in fewer memory
locks. Although this sounds like it would be useful for reducing latency, NUMA
systems have been known to interact badly with realtime applications, as they
can cause unexpected event latencies.
For more information about the NUMA API, see Andi Kleen's whitepaper <ulink
url="http://www.halobates.de/numaapi3.pdf">An NUMA API for Linux</ulink>.
If no further information on this section received by Friday 16 May, then
information currently in the guide will be assumed to be correct. Any further
information/updates to occur in the 1.1 docs.
So, what does BIOS interleaving actually do? And is that what it's always going
to be called in the BIOS setup screen(s)?
We're trying to get something together for user consumption that will give them
an idea of how to setup their system for RT, so the language needs to be clear.
Closing this bug for now. Any further edits/additions to this section to be
included in 1.1 docs (a new bug will be required in that case).