nanog mailing list archives
RE: Followup British Telecom outage reason
From: Joel Jaeggli <joelja () darkwing uoregon edu>
Date: Thu, 29 Nov 2001 12:31:25 -0800 (PST)
Um... The rtl kerenel runs the linux kernel as a pre-ementible low priority thread, has proveable worst case timing around 15uSec between assertion of interrupt and execution of the realtime handler, and is posix compliant. visit: http://www.rtlinux.org/ and http://www.fsmlabs.com/ On Thu, 29 Nov 2001, Youse, Chuck wrote:
You'll forgive me for being cynical here, but I seriously doubt that any Linux-derived operating systems could truly qualify as 'real-time'. To meet the requirements for an RTOS, Linux would have to be so heavily mutated that it would no longer be Linux. Cheers Chuck -----Original Message----- From: Patrick Greenwell To: Christian Kuhtz Cc: Alex Bligh; Paul Vixie; nanog () merit edu Sent: 29/11/01 07:49 Subject: RE: Followup British Telecom outage reason On Wed, 28 Nov 2001, Christian Kuhtz wrote:I guess some time someone will realize routers are both hardware, and software, and shock horror both, if done well, can actually add value. [hint & example: compare the scheduler on, say, Linux/FreeBSD, Windows 95 (sic), and your favourite router OS (*); pay particular attention to suitability for running realtime, or near realtime tasks, where such tasks may occasionally crash or overrun their expected timeslice; note how the best OS amongst the bunch for this aint exactly great]. (*) results may vary according to personal choice here.Don't use a non-realtime OS for something that you expect realtime or near-realtime OS functionality. There are specific systems to addressthesekinds of needs with rather complicated scheduling mechanism toaccomodatesuch requirements in a sensible manner. Is IOS a realtime operating system? No. Are any of the other listedOSrealtime operating systems? No.Actually there are multiple Linux-based RTOSes.
-- -------------------------------------------------------------------------- Joel Jaeggli joelja () darkwing uoregon edu Academic User Services consult () gladstone uoregon edu PGP Key Fingerprint: 1DE9 8FCA 51FB 4195 B42A 9C32 A30D 121E -------------------------------------------------------------------------- It is clear that the arm of criticism cannot replace the criticism of arms. Karl Marx -- Introduction to the critique of Hegel's Philosophy of the right, 1843.
Current thread:
- Re: Followup British Telecom outage reason, (continued)
- Re: Followup British Telecom outage reason jerry scharf (Nov 26)
- Re: Followup British Telecom outage reason Christopher A. Woodfield (Nov 26)
- Re: Followup British Telecom outage reason Brett Frankenberger (Nov 26)
- Re: Followup British Telecom outage reason Ryan O'Connell (Nov 27)
- Re: Followup British Telecom outage reason Alex Bligh (Nov 26)
- Re: Followup British Telecom outage reason Paul Vixie (Nov 26)
- RE: Followup British Telecom outage reason Joel Jaeggli (Nov 29)
- RE: Followup British Telecom outage reason Vadim Antonov (Nov 29)