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by jahboater
Sun Apr 05, 2020 9:11 am
Forum: General discussion
Topic: Why nano?
Replies: 26
Views: 526

Re: Why nano?

Its simple, I am not going to start an Xserver just to run a text editor ...
by jahboater
Sun Apr 05, 2020 8:35 am
Forum: C/C++
Topic: ggc long long int problems.
Replies: 17
Views: 373

Re: ggc long long int problems.

the only thing which is looking odd is how this composite thing "Result is %" PRId64 "\n" could be a valid format string, I would have more suspected "Result is %" + PRId64 + "\n" In C (since C99) literal strings are concatenated simply by placing them next to each other. Here is another example "l...
by jahboater
Sun Apr 05, 2020 8:32 am
Forum: C/C++
Topic: ggc long long int problems.
Replies: 17
Views: 373

Re: ggc long long int problems.

You could also make the literal 65541 be 64-bits by appending LL or changing it to INT64_C(65541)
by jahboater
Sat Apr 04, 2020 3:56 pm
Forum: C/C++
Topic: ggc long long int problems.
Replies: 17
Views: 373

Re: ggc long long int problems.

will things like int64_t aa1 = 1585951665; int64_t aa3; aa3 = aa1 * 65541; always work as they are supposed to? Yes, that's fine. The problem was the mixture of 32 and 64 bit numbers and also that fact that the 32-bit multiply was unsigned (so overflow is OK and does not raise a warning). and which...
by jahboater
Sat Apr 04, 2020 1:06 pm
Forum: C/C++
Topic: ggc long long int problems.
Replies: 17
Views: 373

Re: ggc long long int problems.

Conversely I love Rust because it is terribly fussy about types and tries really hard to stop you shooting your toes off. While at the same time allowing you to do anything by the looks of it. Yes, I like it too. You have precise control over the scalar data types, precise and documented control ov...
by jahboater
Sat Apr 04, 2020 9:24 am
Forum: C/C++
Topic: ggc long long int problems.
Replies: 17
Views: 373

Re: ggc long long int problems.

I have little to no idea about Fortran or D but you will have a hard time getting into the same type confusion in Rust. Rust won't let you mix types like that and overflow/underflow is checked, in debug builds at least. Are you saying that you cant do "i64 = i32 * i32" in Rust ? Doesn't seem unreas...
by jahboater
Sat Apr 04, 2020 8:21 am
Forum: C/C++
Topic: ggc long long int problems.
Replies: 17
Views: 373

Re: ggc long long int problems.

Ah! The simple things will get you every time :( The assignment operator '=' is just another operator in the expression and you might expect the entire rhs of the '=' to be promoted to 64-bits or at least do a "long multiply" to match the lhs. Instead it does a short multiply and zero extends the r...
by jahboater
Fri Apr 03, 2020 1:16 pm
Forum: Advanced users
Topic: Moving Linux Kernel to 5.4
Replies: 48
Views: 1502

Re: Moving Linux Kernel to 5.4

I noticed that the core frequency scaling is no longer working, or is not being reported as working. Here you can see at 14:08:03 a cpu bound program started running on one core. Normally I see the core freq increase to 500MHz. Time Temp CPU Core Health Vcore 14:07:03 35.0'C 720MHz 200MHz 0000000000...
by jahboater
Fri Apr 03, 2020 8:34 am
Forum: Advanced users
Topic: Moving Linux Kernel to 5.4
Replies: 48
Views: 1502

Re: Moving Linux Kernel to 5.4

Runs fine on my Pi4 4GB, Raspbian Lite, 64-bit kernel.
by jahboater
Wed Apr 01, 2020 7:43 pm
Forum: Raspbian
Topic: Are /dev/shm and /run/user/1001 using the same Ramdisk?
Replies: 14
Views: 209

Re: Are /dev/shm and /run/user/1001 using the same Ramdisk?

/dev/shm, /run/user/1000, and /videos in my example are all "tmpfs" which is entirely different. Thanks but I am a little confused on difference between tmpfs and ramfs. They both use memory but ramfs allocates more than tmpfs? Although you said you can specify your own size for a tmpfs folder. So ...
by jahboater
Wed Apr 01, 2020 3:33 pm
Forum: Raspbian
Topic: Are /dev/shm and /run/user/1001 using the same Ramdisk?
Replies: 14
Views: 209

Re: Are /dev/shm and /run/user/1001 using the same Ramdisk?

I believe writing to the ramdisk will be faster than the SD card resulting in less chance of dropped frames. Yes it will be faster. But /run/user/1000 is limited jn space, if instead you create your own:- tmpfs /videos tmpfs defaults,noatime,size=3g 0 0 You can set any size limit you like and set s...
by jahboater
Wed Apr 01, 2020 3:25 pm
Forum: Raspbian
Topic: Raspbian 64 bits
Replies: 9
Views: 287

Re: Raspbian 64 bits

Also from Sakaki see the impressive Gentoo64:

https://github.com/sakaki-/gentoo-on-rpi-64bit

A well engineered and well supported distro, but I prefer Debian.
by jahboater
Wed Apr 01, 2020 3:23 pm
Forum: Raspbian
Topic: Raspbian 64 bits
Replies: 9
Views: 287

Re: Raspbian 64 bits

Heater wrote:
Wed Apr 01, 2020 3:20 pm
A google search like "site:raspberrypi.org sakaki nspwan" or "site:raspberrypi.org sakaki nspwan docker" will turn up other threads here talking about this. User sakaki has done a great job on getting all this working.
Is that "nspawn"?
by jahboater
Wed Apr 01, 2020 3:21 pm
Forum: Raspbian
Topic: Raspbian 64 bits
Replies: 9
Views: 287

Re: Raspbian 64 bits

I would like to know if there are any plans to have a Raspbian full 64 bits ? My main concern is just that finding arm32 programs is more difficult that finding arm64 programs. (for example in the k8s world, a lot of containers don't have an arm32 image, some components (etcd) neither, etc). Regard...
by jahboater
Wed Apr 01, 2020 3:08 pm
Forum: Raspbian
Topic: Are /dev/shm and /run/user/1001 using the same Ramdisk?
Replies: 14
Views: 209

Re: Are /dev/shm and /run/user/1001 using the same Ramdisk?

Why use /dev/shm ? Add this to /etc/fstab and reboot. Then use /tmp (or call it something else if you prefer). tmpfs /tmp tmpfs defaults,noatime,size=3g 0 0 These are not RAM disks by the way. It is tmpfs which is virtual memory. Unlike a ram disk, the actual memory used is only that needed for the ...
by jahboater
Wed Apr 01, 2020 9:12 am
Forum: Advanced users
Topic: Is overclocking dangerous?
Replies: 7
Views: 331

Re: Is overclocking is dangerous?

would decent cooling (to maintain pre-overclock temps) eliminate the loss entirely? what about freq scaling, where its only at 2ghz for say 1% of the time? Why does it matter? I remember an engineer (Gordon) mentioned for the earlier Pi's that the expected lifespan was "35 years, perhaps down to 30...
by jahboater
Wed Apr 01, 2020 8:30 am
Forum: Advanced users
Topic: What is the best overcloking option?
Replies: 2
Views: 115

Re: What is the best overcloking option?

Is this okay for use Pi long and long time? All Pi's are different so we cant answer that. You must stress test it yourself. Run it with a load that's worse than normal, if its OK you know it will be fine in normal use and have a safety margin. Monitor the temperature and use "vcgencmd get_throttle...
by jahboater
Wed Apr 01, 2020 4:26 am
Forum: Troubleshooting
Topic: Overheating rpi 3 b
Replies: 6
Views: 199

Re: Overheating rpi 3 b

superwantutri wrote:
Wed Apr 01, 2020 1:49 am
too hot to touch... it seems its good as dead. hehehe thanks
Use:

Code: Select all

vcgencmd measure_temp
to display the temperature, and post the result here.
Also "uptime" to show the load.
by jahboater
Wed Apr 01, 2020 12:03 am
Forum: Troubleshooting
Topic: plot/statistics of the processor
Replies: 3
Views: 112

Re: plot/statistics of the processor

(CPU load/core, RAM load, frequency, Power consumption) / time Take a look at vmstat (see "man vmstat" for info). Try "vmstat 10 10" for example. vmstat is included with Raspbian. "dstat" looks nicer but you must install it with "sudo apt install dstat" Then just type "dstat". dstat includes networ...
by jahboater
Tue Mar 31, 2020 10:04 pm
Forum: General discussion
Topic: Should you buy an A2 performance rated SD card?
Replies: 25
Views: 4486

Re: Should you buy an A2 performance rated SD card?

In my recent test of seven different 32g cards, the A1 were 3x more expensive but did not have fastest speeds. Measured with cheap USB3 reader using both atto & h2testw which gave similar results: The purpose of the new A1 and A2 class cards is the IOPS (4KB reads/writes per second) hugely importan...
by jahboater
Tue Mar 31, 2020 7:05 pm
Forum: General discussion
Topic: Is my Pi4 hotter than it should be?
Replies: 6
Views: 292

Re: Is my Pi4 hotter than it should be?

Thanks for the responses. It's seems from videos I've seen that in the FLIRC case when idling it should be only in the upper 30's C. I am going to check the actual temperature with my instant reading meat thermometer and see how warm the case actually is. You should measure the temperature with: pi...
by jahboater
Tue Mar 31, 2020 2:29 pm
Forum: General discussion
Topic: 64 bit Raspbian apps
Replies: 5
Views: 196

Re: 64 bit Raspbian apps

Something seems wrong here. Surely cmake should define CMAKE_SIZEOF_VOID_P appropriately and the code should build on 32 bit and 64 bit platforms. Without the need to go and comment them out. +1. Its perfectly easy in this day and age to write C/C++ code that's portable between 64-bit and 32-bit pl...
by jahboater
Tue Mar 31, 2020 11:18 am
Forum: Troubleshooting
Topic: Exported the wrong path in Pi renders all commands useless
Replies: 7
Views: 140

Re: Exported the wrong path in Pi renders all commands useless

So I rebooted as you say and now it works again. I thought export is permanent and you need to find the correct path to fix it. Thanks a bunch! You should add the extra directory to $PATH For example: export PATH=$PATH:/home/pi/.local/bin would leave your existing PATH unchanged. These things becom...
by jahboater
Tue Mar 31, 2020 10:09 am
Forum: Troubleshooting
Topic: Pi 4 won't overclock past 1.75GHz
Replies: 9
Views: 238

Re: Pi 4 won't overclock past 1.75GHz

My config is:-

Code: Select all

over_voltage=2
arm_freq=1800
arm_freq_min=400
arm_64bit=1
without the heat sink I had to use "over_voltage=3"
by jahboater
Tue Mar 31, 2020 9:26 am
Forum: Troubleshooting
Topic: Pi 4 won't overclock past 1.75GHz
Replies: 9
Views: 238

Re: Pi 4 won't overclock past 1.75GHz

I have also raised the voltage yes. What’s weird is that if I set it to 1750 then it overclocks to 1750. If I set it to 1751 it doesn’t work and the processor maxes out at 1.3GHz under load. This makes me think that it might be a software issue rather than my configuration being wrong. It also did ...

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