from the bit-flip-out dept.
There's nothing quite like some fun holiday-weekend reading as a fiery mailing list post by Linus Torvalds. The Linux creator is out with one of his classical messages, which this time is arguing over the importance of ECC memory and his opinion on how Intel's "bad policies" and market segmentation have made ECC memory less widespread.
Linus argues that error-correcting code (ECC) memory "absolutely matters" but that "Intel has been instrumental in killing the whole ECC industry with it's horribly bad market segmentation... Intel has been detrimental to the whole industry and to users because of their bad and misguided policies wrt ECC. Seriously...The arguments against ECC were always complete and utter garbage... Now even the memory manufacturers are starting [to] do ECC internally because they finally owned up to the fact that they absolutely have to. And the memory manufacturers claim it's because of economics and lower power. And they are lying bastards - let me once again point to row-hammer about how those problems have existed for several generations already, but these f*ckers happily sold broken hardware to consumers and claimed it was an "attack", when it always was "we're cutting corners"."
Ian Cutress from AnandTech points out in a reply that AMD's Ryzen ECC support is not as solid as believed.
Related: Linus Torvalds: 'I'm Not a Programmer Anymore'
Linus Torvalds Rejects "Beyond Stupid" Intel Security Patch From Amazon Web Services
Linus Torvalds: Don't Hide Rust in Linux Kernel; Death to AVX-512
Linus Torvalds Doubts Linux will Get Ported to Apple M1 Hardware
Submitted via IRC for soylent_blue
Linus Torvalds, Linux's creator, doesn't make speeches anymore. But, what he does do, and he did again at Open Source Summit Europe in Lyon France is have public conversations with his friend Dirk Hohndel, VMware's Chief Open Source Officer. In this keynote discussion, Torvalds revealed that he doesn't think he's a programmer anymore.
So what does the person everyone thinks of as a programmer's programmer do instead? Torvalds explained:
I don't know coding at all anymore. Most of the code I write is in my e-mails. So somebody sends me a patch ... I [reply with] pseudo code. I'm so used to editing patches now I sometimes edit patches and send out the patch without having ever tested it. I literally wrote it in the mail and say, 'I think this is how it should be done,' but this is what I do, I am not a programmer.
So, Hohndel asked, "What is your job?" Torvalds replied, "I read and write a lot of email. My job really is, in the end, is to say 'no.' Somebody has to say 'no' to [this patch or that pull request]. And because developers know that if they do something that I'll say 'no' to, they do a better job of writing the code."
Torvalds continued, "Sometimes the code changes are so obvious that no messages [are] really required, but that is very very rare." To help your code pass muster with Torvalds it helps to ''explain why the code does something and why some change is needed because that in turn helps the managerial side of the equation, where if you can explain your code to me, I will trust the code."
In short, these days Torvalds is a code manager and maintainer, not a developer. That's fine with him: "I see one of my primary goals to be very responsive when people send me patches. I want to be like, I say yes or no within a day or two. During a merge, the day or two may stretch into a week, but I want to be there all the time as a maintainer."
That's what code maintainers should do.
Linux kernel head Linus Torvalds has trashed a patch from Amazon Web Services (AWS) engineers that was aimed at mitigating the Snoop attack on Intel CPUs discovered by an AWS engineer earlier this year. [...] AWS engineer Pawel Wieczorkiewicz discovered a way to leak data from an Intel CPU's memory via its L1D cache, which sits in CPU cores, through 'bus snooping' – the cache updating operation that happens when data is modified in L1D.
In the wake of the disclosure, AWS engineer Balbir Singh proposed a patch for the Linux kernel for applications to be able to opt in to flush the L1D cache when a task is switched out. [...] The feature would allow applications on an opt-in basis to call prctl(2) to flush the L1D cache for a task once it leaves the CPU, assuming the hardware supports it.
But, as spotted by Phoronix, Torvalds believes the patch will allow applications that opt in to the patch to degrade CPU performance for other applications.
"Because it looks to me like this basically exports cache flushing instructions to user space, and gives processes a way to just say 'slow down anybody else I schedule with too'," wrote Torvalds yesterday. "In other words, from what I can tell, this takes the crazy 'Intel ships buggy CPU's and it causes problems for virtualization' code (which I didn't much care about), and turns it into 'anybody can opt in to this disease, and now it affects even people and CPU's that don't need it and configurations where it's completely pointless'."
Kernel developers appear to be eager to debate the merits of potentially allowing Rust code within the Linux kernel. Linus Torvalds himself has made some initial remarks on the topic ahead of the Linux Plumbers 2020 conference where the matter will be discussed at length.
[...] Linus Torvalds chimed in though with his own opinion on the matter. Linus commented that he would like it to be effectively enabled by default to ensure there is widespread testing and not any isolated usage where developers then may do "crazy" things. He isn't calling for Rust to be a requirement for the kernel but rather if the Rust compiler is detected on the system, Kconfig would enable the Rust support and go ahead in building any hypothetical Rust kernel code in order to see it's properly built at least.
According to a mailing list post spotted by Phoronix, Linux creator Linus Torvalds has shared his strong views on the AVX-512 instruction set. The discussion arose as a result of recent news that Intel's upcoming Alder Lake processors reportedly lack support for AVX-512.
Torvalds' advice to Intel is to focus on things that matter instead of wasting resources on new instruction sets, like AVX-512, that he feels aren't beneficial outside the HPC market.
In a recent post on the Real World Technologies forum—one of the few public internet venues Linux founder Linus Torvalds is known to regularly visit—a user named Paul asked Torvalds, "What do you think of the new Apple laptop?"
If you've been living under a rock for the last few weeks, Apple released new versions of the Macbook Air, Macbook Pro, and Mac Mini featuring a brand-new processor—the Apple M1.
The M1 processor is a successor to the A12 and A14 Bionic CPUs used in iPhones and iPads, and pairs the battery and thermal efficiency of ultramobile designs with the high performance needed to compete strongly in the laptop and desktop world.
"I'd absolutely love to have one, if it just ran Linux," Torvalds replied. "I've been waiting for an ARM laptop that can run Linux for a long time. The new [Macbook] Air would be almost perfect, except for the OS."
[...] In an interview with ZDNet, Torvalds expounded on the problem:
The main problem with the M1 for me is the GPU and other devices around it, because that's likely what would hold me off using it because it wouldn't have any Linux support unless Apple opens up... [that] seems unlikely, but hey, you can always hope.
[...] It's also worth noting that while the M1 is unabashedly great, it's not the final word in desktop or laptop System on Chip designs. Torvalds mentions that, given a choice, he'd prefer more and higher-power cores—which is certainly possible and seems a likely request to be granted soon.