Want to read Slashdot from your mobile device? Point it at m.slashdot.org and keep reading!


Forgot your password?
Slashdot Deals: Prep for the CompTIA A+ certification exam. Save 95% on the CompTIA IT Certification Bundle ×

Comment Re:Status was NOT divulged, only email identities (Score 2) 56

Using CC or BCC as a substitute for a mailing list is a good indicator that the organisation in question has no IT skills at all and probably shouldn't be trusted with any data that you might want to be confidential and that they might want to store on a computer.

Comment Re:Interesting (Score 1) 475

why would you ever want to actually write a sorting algorithm? After all, somebody out there has already done it better, and that's nothing you would ever need to do as real programmer.

This sounds like the assignments were badly designed. Unless your data has an entirely random distribution, with some knowledge of the data that you're sorting you can do a much better job of sorting than any generic comparison-based algorithm. If you're sorting English words, for example (a very common example data set for this kind of thing), then a radix sort implemented by a student will do a better job than a standard library quicksort that's doing a full string comparison on each pair. If the course also asks them to implement a quicksort, and to evaluate both against libc's qsort(), then they should hopefully learn both when it is and when it isn't appropriate to implement their own.

Comment Re:the comparison is pointless (Score 1) 82

How do you know he's a desktop user?

Because (in the part of the post that I quoted in my reply), he said:

-Os frankly is of little interest to desktop developers

And I replied that -Os is relevant to desktop users, which you then disputed by saying that it's not relevant to HPC.

Modern desktops are putting a lot of effort into reducing the number of wakeups per second in orer to reduce power draw. This means that on most systems, there are a lot of processes, but very few running at any given time.

Timer coalescing does the exact opposite. It means that you'll have a single wakeup and then a load of processes run, and then sleep. This increases i-cache pressure, it doesn't reduce it.

Comment Re: Programming (Score 2) 475

The one that bugs me the most is the imbalance between how society treats knowledge of humanities and sciences. If a scientist doesn't know about history, then he fits the 'ignorant scientist' cliche and is a figure of fun. If a historian knows far less about the science that his daily life depends on, then he's considered a cultured and well-rounded individual. And, in my experience, the humanities person who is ignorant of science is far more prevalent than the scientist or engineer who is ignorant of humanities.

Comment Re:Programming (Score 1) 475

First: NIST? Really? I guess you've not been paying attention for the last couple of years.

Second: You misunderstand the grandparent. If you don't understand the basic ideas behind a crypto algorithm (or, more importantly, crypto protocols) then you will pick the wrong one. No matter how good a cypher is, or how verified the implementation is, if used incorrectly it will still be insecure.

Comment Re:I don't see anything different. (Score 1) 127

Serif fonts work fine on small devices, they don't work well at low DPI. Which, in an age of 200+DPI on cheap devices, means that this move makes little sense. The only reason that the scaling is a problem would be if they're doing something stupid, like using a bitmap image rather than a vector. And, of course, a quick trip to google.com confirms that they are, indeed, using a png rather than an svg (with png fallback if they care that much) for their logo.

So, the real story here is that, in 2015, web giant Google has yet to learn that resolution-independent images are a thing.

Comment Re:The same basic approach works everywhere (Score 1) 99

It's pretty easy on anything running X11, where the authentication of things that are allowed to deliver arbitrary input events to other applications is 'oh, you're a program that can read this user's home directory or from a trusted IP address? Go right ahead! By the way, if you're not then you're not allowed to put windows on the screen.' Windows has a similar mechanism, but has a special category of window that can only receive input from privileged components (i.e. real input devices and designated assistance apps). I filed a bug with Apple about the ease of spoofing the Keychain authorisation and privilege elevation dialogs against OS X 10.2. Maybe by 10.11 they'll fix it...

Comment Re:Yay for OSX (Score 1) 82

LLVM was originally developed as a research project at UIUC, by Chris Lattner supervised by Vikram Adve. It was offered to the FSF as a new optimisation framework for GCC, but the FSF turned it down. Chris was hired by Apple and they used LLVM for the CPU fallback path for their GLSL compiler (giving them a compiler that could target SSE and AltiVec and work on x86 and PowerPC, both 32-bit and 64-bit variants, reusing the same code for most of the implementation as the interpreter). In 2007, Chris began work on a new C front end and open sourced it. Initial work on Clang (basically getting it up to the point where it was as more-or-less useable C compiler, could parse Objective-C, and had a token nod at C++) was done entirely in Apple and then a lot of the development was done at Apple. A few of the other bits are still led by Apple people: the Clang static analyser is mostly developed by Apple people and the work on statepoints / patchpoints in LLVM was led by Apple's WebKit JavaScript team (though now there's a lot of work from people at Azul and MSR).

Comment Re:the comparison is pointless (Score 1) 82

If you're doing HPC, then you're definitely not the kind of 'desktop user' that the grandparent was talking about. For a single compute-bound application consuming all of the system resources, -O2 or -O3 will almost always win (unless they manage to blow out L1 i-cache on a hot loop, which does happen but is quite rare). When you benchmark systems with a lot of active processes, then the numbers become very different, because cache contention starts to matter (so does TLB contention, though on x86 with the hardware page table walker, fills are cheap if they hit in L1, so this boils down to cache contention again).

Comment Re:No Apple (Score 1) 95

Nonsense. The income that you'll get is number of people in the market multiplied by amount that you can get from each one. People with luxury yachts will spend a lot, but there are hardly any of them. If there are 4 times as many Android users as iOS users, but iOS users are willing to part with 5 times as much money (on average), then iOS is a better market to be in. Even if iOS users are only willing to spend 3 times as much, it's still a good market to be in because each customer likely adds to your support / accounting costs and having a slightly lower income with a quarter of the number of customers may be more profitable.

Comment Re:No Apple (Score 1) 95

You're talking about hardware makers. I'm talking about software vendors. If I make an iOS app and an Android app, what proportion of Android users will buy it, what proportion of iOS users will? If 4% of iOS users and 1% of Android users are willing to hand over money for it, then that's about the same amount from each platform. Numbers that I've seen are a bit out of date now, but they showed that iOS users were spending a lot more (per capita) than Android users, as most Android users only install free (including ad supported) apps, and ad revenue is far less than a direct sale can make.

What is now proved was once only imagin'd. -- William Blake