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by ejolson
Tue Jan 22, 2019 9:19 pm
Forum: Scratch
Topic: Scratch 1, 2 or 3
Replies: 4
Views: 4104

Scratch 1, 2 or 3

I read in another post that it takes 70% of the available CPU just to drag a block into a program using Scratch 3 on the Pi. This would seem to rule out either the Pi or Scratch 3 as an attractive programming environment for children, especially since many children are less forgiving than many adult...
by ejolson
Tue Jan 22, 2019 4:07 am
Forum: General discussion
Topic: 64-bit operating system
Replies: 358
Views: 139322

Re: 64-bit operating system

I'm rewriting my assembly language book that uses the Raspberry Pi, and I would like to use AARCH64 because it's a cleaner architecture. Using 64-bit for the book seems like a reasonable idea. By the time the book goes to press 64-bit will likely be standard even on Raspberry Pi. For now one could ...
by ejolson
Tue Jan 22, 2019 1:27 am
Forum: Off topic discussion
Topic: Why Avoid BASIC on RPi?
Replies: 2312
Views: 163537

Re: Why Avoid BASIC on RPi?

ejolson , Before doing anything in user space you need to employ some operating system feature to actually start the threads. It further appears the pool of worker threads is blocking instead of spinning when there is no work to do. This also requires interaction with the kernel. Thinking about it,...
by ejolson
Tue Jan 22, 2019 1:16 am
Forum: Off topic discussion
Topic: Why Avoid BASIC on RPi?
Replies: 2312
Views: 163537

Re: Why Avoid BASIC on RPi?

This BASIC thing has really gone to your head! I'm just trying to stay off topic in this off-topic thread. Along those lines, it would be nice if a RISC OS BBC BASIC code (with or without inline assembler) were to appear. I have finished writing visual.bas, a version of the Fibonacci code in Visual...
by ejolson
Sun Jan 20, 2019 7:52 pm
Forum: Off topic discussion
Topic: Why Avoid BASIC on RPi?
Replies: 2312
Views: 163537

Re: Why Avoid BASIC on RPi?

Ah, but, I don't believe that HPX does create the entire directed graph of execution first, before it actually does any work. Even if I may have implied as such above. Rather it is spawning threads, growing graph, executing threads, which "prunes" the graph, all dynamically as it runs. Either way, ...
by ejolson
Sun Jan 20, 2019 6:46 pm
Forum: Off topic discussion
Topic: Why Avoid BASIC on RPi?
Replies: 2312
Views: 163537

Re: Why Avoid BASIC on RPi?

In this way, so they claim, all that time we wasted with our old fork/join at every level is no longer wasted, if a processor becomes idle work for it to do can be found. The way task spawn and sync are currently implemented in both Cilk and OpenMP behind the scenes using work stealing also keeps a...
by ejolson
Sun Jan 20, 2019 2:39 pm
Forum: Off topic discussion
Topic: Why Avoid BASIC on RPi?
Replies: 2312
Views: 163537

Re: Why Avoid BASIC on RPi?

I just noticed that letting the output dump to the screen rather than sending it to the bit bucket doubles the run time. At which point I wonder if there is any point in getting the computation to run faster? Scrolling a million digits through a GUI is likely to take some time. Sending the output t...
by ejolson
Sun Jan 20, 2019 10:55 am
Forum: Off topic discussion
Topic: Why Avoid BASIC on RPi?
Replies: 2312
Views: 163537

Re: Why Avoid BASIC on RPi?

Heater wrote:
Sun Jan 20, 2019 9:47 am
Intel's names are OK.

It's just that there is so many of them. It has taken me two or three weeks now to find out what this chip is!
With the -mtune and -march flags set appropriately does -O3 now produce faster executables than the -O2 setting?
by ejolson
Sat Jan 19, 2019 10:00 pm
Forum: Off topic discussion
Topic: Why Avoid BASIC on RPi?
Replies: 2312
Views: 163537

Re: Why Avoid BASIC on RPi?

MULTI-CORE RUN TIMES MEASURED IN SECONDS Win10 PC Pi 3B parallel: 0.227s 1.075s fibo_karatomp: 0.234s 1.489s fibo_karatasync: 0.303s 1.789s It's confusing, we are all over the map in relative performance, changing with cores and platforms. Running the C++ code fast on recent Intel hardware appears ...
by ejolson
Sat Jan 19, 2019 7:22 pm
Forum: Off topic discussion
Topic: Why Avoid BASIC on RPi?
Replies: 2312
Views: 163537

Re: Why Avoid BASIC on RPi?

ejolson, The above hardware features may affect the assumption used in parallel.c that loops with if statements are slow compared to vectorisable arithmetic kernels. Yes, one might naturally assume that sticking a conditional inside a tight loop would slow things down a lot. That was certainly the ...
by ejolson
Sat Jan 19, 2019 9:44 am
Forum: Off topic discussion
Topic: Why Avoid BASIC on RPi?
Replies: 2312
Views: 163537

Re: Why Avoid BASIC on RPi?

Or something even more subtle that makes the code more friendly to Intel's multiple dispatch, branch prediction, speculative execution or whatever other magic goes on those CPU's. The above hardware features may affect the assumption used in parallel.c that loops with if statements are slow compare...
by ejolson
Sat Jan 19, 2019 2:41 am
Forum: Off topic discussion
Topic: Why Avoid BASIC on RPi?
Replies: 2312
Views: 163537

Re: Why Avoid BASIC on RPi?

I think my whole fibo(4784969) challenge idea is driving me insane.... Congratulations. Your parallel C++ code seems much better suited to 64-bit Intel hardware than my parallel C code. Here are the compilation options: /usr/local/gcc-8.2/bin/gcc -O3 -march=native -mtune=native -fopenmp -o parallel...
by ejolson
Sat Jan 19, 2019 12:30 am
Forum: Off topic discussion
Topic: Why Avoid BASIC on RPi?
Replies: 2312
Views: 163537

Re: Why Avoid BASIC on RPi?

I have a theory how the gcc backend got broken in Free Basic: I think Free Basic generates C89 compliant code but newer versions of gcc since 5.x use C99 as the default. No, it's just plain broken. Automatic variables in the function that called setjmp() (in FreeBasic's case the entire program is i...
by ejolson
Fri Jan 18, 2019 5:04 pm
Forum: Off topic discussion
Topic: Why Avoid BASIC on RPi?
Replies: 2312
Views: 163537

Re: Why Avoid BASIC on RPi?

it would be nice if a RISC OS BBC BASIC code were to appear. Just for fun I set an integer version of my code running. It finishd after 1117 minutes . :-) That is extreme, because there are some optimisations still available. It is lucky that the Raspberry Pi runs on only a watt or two of electrici...
by ejolson
Fri Jan 18, 2019 8:48 am
Forum: Off topic discussion
Topic: Why Avoid BASIC on RPi?
Replies: 2312
Views: 163537

Re: Why Avoid BASIC on RPi?

This BASIC thing has really gone to your head! I'm just trying to stay off topic in this off-topic thread. Along those lines, it would be nice if a RISC OS BBC BASIC code (with or without inline assembler) were to appear. I have finished writing visual.bas, a version of the Fibonacci code in Visual...
by ejolson
Thu Jan 17, 2019 9:02 pm
Forum: Other programming languages
Topic: golang?
Replies: 22
Views: 43401

Re: golang?

truthadjustr, Perhaps, the killer-app for C++ is still coming ? Joint Strike Fighter software? So much that we use everyday is written in C++. That does sound like a killer app. Do you use it everyday? The main problem with Go, in my opinion, is that it is still difficult to write using EBCDIC enco...
by ejolson
Thu Jan 17, 2019 7:02 am
Forum: Off topic discussion
Topic: Why Avoid BASIC on RPi?
Replies: 2312
Views: 163537

Re: Why Avoid BASIC on RPi?

$ node > a = [1, 2, 3, 4] [ 1, 2, 3, 4 ] > b = [5, 6, 7, 8] [ 5, 6, 7, 8 ] > t = a [ 1, 2, 3, 4 ] > a = b [ 5, 6, 7, 8 ] > b = t [ 1, 2, 3, 4 ] No array copy happens there. Nice! For completeness, how do you delete the t variable after all that so the reference counts stay one? Or is something else...
by ejolson
Thu Jan 17, 2019 6:39 am
Forum: General discussion
Topic: New SystemD Vulnerabilities
Replies: 14
Views: 2628

Re: New SystemD Vulnerabilities

From what I heard from youtube, this vulnerabilities only can be triggered by someone with physical access to the system or there are other vulnerabilities on the system allow privileged access to become effective. Please correct me if my understanding is wrong. I think it is a local privilege esca...
by ejolson
Thu Jan 17, 2019 5:39 am
Forum: Off topic discussion
Topic: Why Avoid BASIC on RPi?
Replies: 2312
Views: 163537

Re: Why Avoid BASIC on RPi?

Steve Drain, Excellent! Your code will certainly be entering the fibo_4784969 hall of fame. Let me look it over and try to get it to run first. In addition to a nice use of the built-in vector operations of BBC Basic, the code makes paradigmatic use of the swap statement to avoid unnecessary copyin...
by ejolson
Thu Jan 17, 2019 3:05 am
Forum: General discussion
Topic: New SystemD Vulnerabilities
Replies: 14
Views: 2628

Re: New SystemD Vulnerabilities

Heater wrote:
Wed Jan 16, 2019 9:19 am
$ systemctl daemon-reexec
Great. Presumably one can do

# apt-get update; apt-get upgrade

and the systemctl happens automatically no reboot required.
by ejolson
Wed Jan 16, 2019 10:05 pm
Forum: Off topic discussion
Topic: Why Avoid BASIC on RPi?
Replies: 2312
Views: 163537

Re: Why Avoid BASIC on RPi?

A C64 with a card reader sounds like a great project... Unfortunately a proper keypunch is even more expensive to ship by mail than an old Xeon server. Do you think one can be made using a 3D printer? It would be fun to have kept a good working ASR-33 teletype back when such things were possible to...
by ejolson
Wed Jan 16, 2019 9:30 pm
Forum: Off topic discussion
Topic: Why Avoid BASIC on RPi?
Replies: 2312
Views: 163537

Re: Why Avoid BASIC on RPi?

Basically the temp ramps up to 80C and then a bit latter I gets throttled from 1.2Gz to about 1GHz, on a previous run 900MHz. I run my Pi 3B by default at 900MHz because at 1200 it crashes. Overvolt mostly eliminates the crashes, however, except for computing Fibonacci numbers, the main use of that...
by ejolson
Wed Jan 16, 2019 7:44 pm
Forum: Off topic discussion
Topic: Why Avoid BASIC on RPi?
Replies: 2312
Views: 163537

Re: Why Avoid BASIC on RPi?

"low core" sounds like a reference to the hidden security and management cores the likes of Intel hide in our processors today that we have no access to. It also seems to hint at power analysis side-channel attacks. It seems Lee Schneider and Todd Voros were as prophetic as they are funny. Maybe it...
by ejolson
Wed Jan 16, 2019 12:23 pm
Forum: Off topic discussion
Topic: Why Avoid BASIC on RPi?
Replies: 2312
Views: 163537

Re: Why Avoid BASIC on RPi?

Fibo 4784969 Digits 1000000 107273956418004772293649 801767643812806105156269 Time 263:47.43 Fantastic! Another version in Basic. Since there is no inline assembler, does your code work with Richard's port of BBC Basic to Raspbian? I wonder how difficult it would be to add the Karatsuba algorithm. ...
by ejolson
Wed Jan 16, 2019 8:22 am
Forum: General discussion
Topic: New SystemD Vulnerabilities
Replies: 14
Views: 2628

Re: New SystemD Vulnerabilities

I don't have much to say about schismd from a technical perspective. People complain it is not "Unix" style and sticks it's fingers into too many things.Maybe, I don't know. From a user perspective I have found it very simple, useful and reliable. So much easier than messing with all those start up...

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