For some reason (I guess it is the job…) I was browsing through the Power ISA version 2.06 specification last week and hit the following gem of an instruction: “rvwinkle“. It is named after a short story I had never heard about, but which apparently is sufficiently well-known in the US literary canon to warrant a sleep mode being named after it.
Continue reading “Power Architecture Rip Van Winkle”
The presentations from the 2009 Swedish Workshop on Multicore Computing (MCC 2009) are now online at the program page for the workshop. Let me add some comments on the workshop per se.
Continue reading “MCC 2009 Presentations Online”
My post on SiCS multicore, as well as the SiCS multicore day itself, put a renewed spotlight on the GPGPU phenomenon. I have been following this at a distance, since it does not feel very applicable to neither my job of running Simics, nor do I see such processors appear in any customer applications. Still, I think it is worth thinking about what a GPGPU really is, at a high level.
Continue reading “GPGPU – a new type of DSP?”
About two months ago, Cavium Networks launched their second generation of Octeon chips, the Octeon II. The most obvious difference to the previous generation (Octeon, Octeon Plus) is a new MIPS64 core with much better support for hypervisors and virtualization. There are some other interesting aspects to this chip, though.
Continue reading “Cavium Octeon II: Short Notes”
When I started out doing computer science “for real” way back, the emphasis and a lot of the fun was in the basics of algorithms, optimizing code, getting complex trees and sorts and hashes right an efficient. It was very much about computing defined as processor and memory (with maybe a bit of disk or printing or user interface accessed at a very high level, and providing the data for the interesting stuff). However, as time has gone on, I have come to feel that this is almost too clean, too easy to abstract… and gone back to where I started in my first home computer, programming close to the metal.
Continue reading “The Hardware-Software Interface is where the Action Is”
Yes, when does hardware acceleration make sense in networking? Hardware acceleration in the common sense of “TCP offload”. This question was answered by a very nicely reasoned “no” in an article by Mike Odell in ACM Queue called “Network Front-End Processors, Yet Again“.
Continue reading “When does Hardware Acceleration make Sense in Networking?”
In a very roundabout way, I recently got to hear about a cool Sun server feature introduced sometime back in 2003 or 2004: the SCC System Configuration Card. This is a smart card that stores the system hostid and Ethernet MACs, along with other info, and which can be transferred from one server to another.
Continue reading “Cool Obscure Hardware: Sun SCC and Software License Protection”
In Episode 157 of Security Now,Steve Gibson and Leo Laporte discuss the recently discovered security issues with DNS. In particular, the cost of making a good fix in terms of bandwidth and computation capacity. Fundamentally, according to Steve, today’s DNS servers are running at a fairly high load, and there is no room to improve the security of DNS updates by for example sending extra UDP packets or switching to TCP/IP. As this theoretically means a doubling or tripling of the number of packets per query, I can believe that. The “real solutions” to DNS problems should lie in the adoption of a truly secured protocol like DNSSEC. As this uses public key crypto (PKC), it would add a processing load to the servers that would kill the DNS servers on the CPU side instead…
Continue reading “DNS: Hardware Accelerator Time!”
The Radio Register has a nice interview with Kunle Olukotun, the man most known for the Afara/Sun Niagara/UltraSparc T1-2-etc. design. It is a long interview, lasting well over an hour, but it is worth a listen. A particular high point is the story on how Kunle worked on parallel processors in the mid-1990s when everyone else was still chasing single-thread performance. He really was a very early proponent of multicore, and saw it coming a bit before most other (general-purpose) computer architects did. Currently, he is working on how to program multiprocessors, at the Stanford Pervasive Parallelism Laboratory (PPL). In the interview, I see several themes that I have blogged about before being reinforced…
Continue reading “Kunle Olukotun Interview: Heterogeneity, Domain-Specific Programming”
I do find it kind of funny when marketing names go bad in unexpected ways of collide in unexpected ways. There is this fairly old Infineon combined DSP/MCU core called TriCore (the name means it is both a RISC, a DSP, and an MCU). It was a nice name, easy to recognize, easy to pronounce, unlike the competition at the time. Today though, we are seeing multicore chips with three cores on the die. So what are these, if not tri-core chips, in analog with single- dual- quad- oct- etc. And this makes it very necessary to use the hyphen. For example, the Freescale recent StarCore 8113 chip with three cores has its press release explicitly headed tri-core with an hyphen. I guess marketing would have liked the more visually pleasing tricore moniker along with dualcore, which looks fairly established.
Ah well, not to mention the fun Infineon will have if it launches a triple-core TriCore device. Maybe in a third generation TriCore 3? The power of three, indeed. TriTriTriCore possibly?
The Register has a few podcasts in addition to their website, and the one called “Semicoherent Computing” has turned into a very nice series of interviews with interesting people from the computer industry. I recently listened to their interview from September 2007 with David Ditzel of Transmeta fame. He had a lot to say about the history of computing, as well as interesting things on where computing is going. Well worth a listen! Particular interesting highlights…
Continue reading “David Ditzel Interview at The Register/Semicoherent Computing”
I got another email from my friend with the thesis that processors will become ever more homogeneous as time goes on, while I believe in a relative heterogenezation (is that a word?) of computer architecture with many special-purpose accelerators and helper processors. This argument is put forward in a previous blog post. In this round, the arguments for homogenization are from the gaming world.
Continue reading “Heterogeneous vs homogeneous systems, revisited”
Intel has a really neat tool on their homepage: the Intel ARK — Automated Relational Knowledgebase. It is a horrible name for a brilliant tool: it lets you search for processor names, codenames, chipsets, and jump around in a database of processor variants, compatible chipsets, feature lists, and more. Not that I care particularly about Intel chips, but the tool is something everyone selling silicon devices should copy. Being able to quickly figure out just what is inside a certain device (and what is not), and finding related devices and compatible chips is just brilliant for curious people, customers, and supporting services.
Please, everybody else?
The register report “IBM embraces – wtf – Sun’s Solaris across x86 server line” is a very appropriate headline for something quite surprising. The day before this happened, we discussed the announced announcement and said “nah, it can’t be about operating systems”. The idea of IBM in-sourcing Solaris for x86 just felt like the kind of thing that was in the same realm as flying pigs, freezing hells, and similar unlikely events.
Continue reading “Solaris to IBM, x86 to Apple, Power to Microsoft, and other flying pig events”