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Grading on a Curve
Although university professors aren’t trained as teachers, many parts of teaching — lecturing, answering questions, creating tests — come naturally to most of us. Assigning grades, on the other hand, is a part of the game that I’ve never felt very comfortable about. Part of the problem is that as a student I found grades…
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On the Synergy Between Facebook and CAN Bus Error Confinement
One of my favorite lectures in my embedded systems class covers the design of CAN bus: a highly robust network most often used in automotive applications. CAN’s design is elegant in many ways and it includes several mechanisms to help keep the network operating under adverse conditions. One of these mechanisms is error confinement (see…
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Benchmarking Short Codes on Modern Processors
Around 15 years ago, as a newish graduate student, I got access to a Pentium-based Linux machine. One of the coolest things about this machine was the new RDTSC instruction that measured the number of clock ticks since the processor had been reset. This could be used to directly observe cache misses, branch mispredictions, and…
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A Quick Update to Comparing Compiler Optimizations
Saturday’s post on Comparing Compiler Optimizations featured some work done by my student Yang Chen. Since then: There has been some discussion of these problems on the GCC mailing list; some of the problems are already in the Bugzilla and a new PR was filed. A patch fixing the problem is already available! On Sunday…
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Sometimes the Name Is the Contribution
Every now and then I read or re-read a famous, influential paper and realize (or at least suspect strongly) that it did not — at the time it was published — contain any new ideas. My guess is that a paper like this can become highly cited for one or more of the following reasons:…
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Comparing Compiler Optimizations
[Update from Dec 14: Some of these problems have already been fixed! Details here.] [This is a guest post by my grad student Yang Chen, describing one of the projects he’s been working on lately. I elaborated on some of Yang’s points, edited, and did some formatting for WordPress.] Our goal is to help C…
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Taking Grants for Granted
Proposal-writing talent is unevenly distributed among researchers, and so is grant money. Furthermore, there are strong positive feedback loops where grant money leads to more publications, bigger group size, and increased reputation, all of which make it easier to get subsequent awards. It struck me, then, while skimming the list of Google Research Award winners…
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The Official Utah State Firearm
From yesterday’s Salt Lake Tribune I learned that Utah may get a state gun: the Browning M1911 semiautomatic pistol, designed by Utahn John Browning. Utah would be the first state to get its own gun. While this is an interesting idea, I’m not sure that .45 is the right caliber: The Utah state animal is…
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Interviewing PhD Students
Although I work with a great collection of students, I’ve come to realize that my selection of students is based too much on luck and not enough on my skill in evaluating them. Therefore, I have a serious question for the professors out there, and particularly for the computer science professors in systems-related areas: Given…
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Wanted: Invariant-Based Synchronization
Although a significant fraction of the programming languages community works on detecting race conditions in multi-threaded software, I haven’t been able to get very excited about this. Certainly race-free programs have some nice properties, but race freedom is neither a necessary nor sufficient condition for concurrency correctness. This research area doesn’t feel to me like…