dezgeg

11 ms·

151.
by dezgeg 3y ago
fscanf() is also pretty slow because of thread safety so each call involves a mutex (which goes unused 99% of the time). I wonder do the new C++ libraries have faster non-threadsafe options?
152.
by dezgeg 3y ago
I would guess most 32-bit microcontrollers and any SoCs capable of running Linux have some sort of boot ROM, at least for the flash programming mode (especially if it's over USB).
153.
by dezgeg 3y ago
Doesn't really help when the VC firmware is loaded from the SD card anyways
154.
by dezgeg 3y ago
Can't you segfault in Java via stuff in sun.misc.Unsafe?
155.
by dezgeg 3y ago
I guess there the digital beamforming is enough for many use cases.
156.
by dezgeg 3y ago
I think you could make a program to mmap() all the files you want and then call mlockall() and never exit.
157.
Reducing patch postings to Linux-kernel(lwn.net)
77 points by dezgeg 3y ago|32 comments
158.
by dezgeg 3y ago
That's not what they meant. Yes, anybody can write bare metal alternative to Linux ( at the very least by looking at the Linux codebase). But still that Pi 1541 depends on the bootcode.bin, fixup.dat and start.elf binary blobs, which
159.
by dezgeg 3y ago
What would be your solution with regard to iterator invalidation?
160.
by dezgeg 3y ago
That was the original dream for DT that so far hasn't been very successful. In practice the kernel only wants to add support for DTs that conform to a reviewed and approved schema, but most/no manufacturer wants to do the effort o
161.
by dezgeg 3y ago
Yes, DT is mainly meant to describe non-discoverable hw blocks inside the SoC and the chips soldered to the motherboard. Discoverable devices like PCIE cards or USB devices aren't added to DT (except under very rare circumstances) Now
162.
by dezgeg 3y ago
In practice signals don't seem to be a problem for (most?) proc files as the seq_file infrastructure doesn't bother to check for pending signals and terminate the read if so. Naturally, only source reading will answer whether the
163.
by dezgeg 3y ago
Because for some reason many C programmers still insist on 80-character line length limit and 8-wide tab indentation, so something has to give to fit all on the screen
164.
by dezgeg 3y ago
I doubt many people would consider it easy. How many people running their stuff on EC2 would like to hear at some point that to upgrade the newest instance type you need to remake your VMs/containers?
165.
by dezgeg 3y ago
Debian has already started compiling it, and even more will be by the time this new incompatible ISA would hit the shelves. The time to 'get it right' has already passed IMO. If a hard ISA compatibility break happens at this stage
166.
by dezgeg 3y ago
eCPRI, or essentially radio signal over ethernet (ie. from base station indoors to radio module at top of the tower/roof) is another interesting use case (with even stricter latency requirements than audio).
167.
by dezgeg 3y ago
Anybody using the standard embedded build solutions like Buildroot or Yocto will get Rust support without doing anything. It's already there and implemented.
168.
by dezgeg 3y ago
"Most" is a very heavy claim. Any concrete evidence of this? Also in embedded Linux I guess we are technically "building from source", when using a build system like Buildroot or Yocto. But Rust is already supported ther
169.
by dezgeg 3y ago
Did you try just dup2()'ing a new socket file descriptor over the old socket file descriptor? Probably it bring other kinds of problems, but would be interesting to hear what they are.
170.
by dezgeg 3y ago
I'd guess that back then system call overhead was lower than with modern CPUs with deep pipelines, speculation and their vulnerability workarounds.
171.
by dezgeg 3y ago
Nothing forces it to be in ROM. See for example https://github.com/carlosedp/riscv-bringup/blob/master/unlea... where DRAM init seems to be in the FSBL part which is loaded from the SD card.
172.
by dezgeg 3y ago
With compile_commands.json it's been possible for quite a while now.
173.
by dezgeg 3y ago
I wonder how many of such drivers that would in reality only work when those two are called in succession
174.
by dezgeg 3y ago
It's expi.htm.br inside http://www.p01.org/expi/expi.zip
175.
by dezgeg 3y ago
Please use the official mailing list archive (lore.kernel.org). The others are much worse (and non-official).
176.
by dezgeg 3y ago
I think that was partially his point - on 6502, typical-looking C code will be horrifically inefficient, at least when compared to other architectures more suitable for C. For 6502, to get the optimum assembly you'd have to structure y
177.
by dezgeg 3y ago
Whenever the filesystem is being snapshotted atomically, no. That would be effectively same state as from a power-cut at that exact moment. It is correct though, that trying to do it with something like 'cp' on a live database wil
178.
by dezgeg 3y ago
How well does ASAN cope when the libraries your application uses aren't compiled with ASAN? Does it cause false negatives or false positives?
179.
by dezgeg 3y ago
I've found yocto package availability quite good, although you may need to add some non-default meta layers. Do you have some examples of what packages and especially architectures Yocto is missing compared to debian? Also I would be i
180.
by dezgeg 3y ago
If you don't want to error/warn on invalid UTF-8 but instead handle it with the "garbage in, garbage out" principle, then yes you're right, treating them pure byte streams works.

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