Bug 437167 - Need NUMA content in Realtime Tuning Guide
Summary: Need NUMA content in Realtime Tuning Guide
Keywords:
Status: CLOSED NEXTRELEASE
Alias: None
Product: Red Hat Enterprise MRG
Classification: Red Hat
Component: Realtime_Tuning_Guide
Version: beta
Hardware: All
OS: Linux
low
low
Target Milestone: ---
: ---
Assignee: Lana Brindley
QA Contact: Jeff Needle
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2008-03-12 18:30 UTC by Clark Williams
Modified: 2013-10-23 23:06 UTC (History)
6 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Clone Of:
Environment:
Last Closed: 2008-05-29 03:27:01 UTC
Target Upstream Version:
Embargoed:


Attachments (Terms of Use)

Description Clark Williams 2008-03-12 18:30:28 UTC
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.

Comment 1 Lana Brindley 2008-03-27 00:47:09 UTC
Added the following section to the "Realtime Tuning" chapter, until more info
received:

<section
id="sect-Realtime_Tuning_Guide-Realtime_Specific_Tuning-Non_Uniform_Memory_Access">
<title>Non-Uniform Memory Access</title>
<para>
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.
</para>
<para>
For more information about the NUMA API, see Andi Kleen&#39;s whitepaper <ulink
url="http://www.halobates.de/numaapi3.pdf">An NUMA API for Linux</ulink>.
</para>
</section>

LKB

Comment 3 Lana Brindley 2008-05-05 23:47:47 UTC
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.

LKB

Comment 6 Clark Williams 2008-05-16 21:47:50 UTC
Shak,

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. 

Comment 7 Lana Brindley 2008-05-29 03:27:01 UTC
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).

LKB


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