> I was really elated to see how people were so interested and getting to see what peer review in science actually looks like. How in the real world it is done outside of journals and conferences, which people frequently give the misnomer "peer review." I hope people will walk away from this experience with a better understanding of how science works and why replication is such a critical aspect of it.
I saw people become enamored with a Russian anime cat girl on twitter.
This was vapid, consumptive entertainment. Which is perfectly fine, let's just not pretend it's better than the bachelor because science. Replace Chad had a date on love island with Anime cat girl did the science things, and that's about where we're at.
I wonder if the enlightened future-people will consider the institutional exclusion of asian people from higher education on the basis that there are too many others of the same race in colleges, to be pro-racism or anti-racism.
> That’s what Apple explicitly says. Why they don’t match with measurements is another matter… (and no, it’s not a typo)
Ridiculous. You're just making things up. It clearly doesn't have a 160kB 6-way L1 dcache. Nor are the small cores 64kB 6-way -- those don't even divide that's ridiculous. Why do you say it's not a typo?
They "explicitly" say it is 160kB in that backwater code comment. They also explicitly say it's 128kB in this presentation https://www.youtube.com/watch?v=5AwdkGKmZ0I&t=534s so what makes your source the authoritative one?? Pretty obviously it's a quick cut and paste job with a typo (two in one line actually) in it.
> ECC? Needs hugepages? Or hardware erratum? I don’t know for sure.
ECC? Erratum? Come on. It's clearly because it's 128kB.
Apple definitely takes advantage of VI=PI for their caches.
160kB is not a good size for a cache, surely must be a typo.
i$ has more options for handling aliases. You don't actually even need to eliminate them at all because it's a read-only cache. So it's not unusual to see these caches exceed the VI=PI geometry.
I haven't listened to the whole thing but that part of the talk you linked is really cringey actually. To paraphrase, "don't trust a person to write software if they haven't written a first level interrupt handler".
Utter rubbish. And he goes on to talk about programming for an embedded SoC, etc. Hah. Some of the most utterly wretched code, vhdl, and development practices I've ever had the displeasure of being acquainted with have been in embedded devices, devices, device driers, firmware, etc.
And first level interrupt handlers? He's saying that like it takes some genius to do it, or the process of doing it confers some deep understanding on the writer. It doesn't. It's not particularly complex, outside buggy or stupid architecture but even that's just grinding work.
And the there is some horrific buggy crappy interrupt handler code around and I can say that because I've written some. And it sounds like you may well have too, if your interactions with David Miller relating to the the performance of Sun OS system calls is anything to go by.
Arguably it's more valuable to understand how the C environment (stack, etc) is set up and how to wrangle the toolchain into emiting code at particular locations and such. But you can get all that many other ways. And even then, I don't actually agree that you need to know the minutiae of those details in this day and age which is a great thing. This is not where most of the interesting work is happening, like it or not.
This kind of elitist gatekeeping attitude is just sad. It reeks of the has-been (or maybe never-was) mindset. I would just as well trust code written by someone who deeply understands what they do writing a word processor or video game or distributed database, than someone who has hacked out an interrupt entry vector. And the sad fact is that being an OS developer does not require or confer a deep understanding of how to get the most out of hardware, understanding caches or multiprocessing or branch predictors or performant scalable data structures and synchronization techniques. No more than writing a web server prevents a person from understanding all those things deeply.
Get off your high horse and shove your accusations of complicity and ignorance, and you educate yourself before you start throwing stones: Re-read my post and don't bother replying unless you can understand and accept that I never once suggested hardware was not complex.
I said the software interfaces to them have not exploded in complexity, i.e., specifically refuting the suggestion that we don't "have the resources to cope with the monstrous complexity of hardware now", from the point of view of driving them with software. You utterly failed to refute anything that I actually wrote, but after your tantrum is over feel free to have an attempt.
And I work at the line and on both sides of it logic, architecture, and software, so don't bother with the vapid appeals to authority.
> A perennial complaint; Rob Pike had a trollier but similar version years back. I'm not nearly as optimistic that we have the resources to cope with the monstrous complexity of hardware now.
"Hardware" (read: device drivers) is not notably complicated IMO.
That's not to say they're simple, but driving devices from a software point of view is pretty similar to interacting with other software. You read the spec (APIs), write code to set up data structures or registers a certain way, parse responses, etc.
Writing a modern full fledged USB stack is very complex, but would not be more complex than writing a modern full TCP/IP stack for example.
A lot of device programming models have gotten simpler too. Device drivers used to be notorious deep voodoo magic e.g., in cases of the IDE disk driver, but that was not really "complexity" of the software logic so much as hundreds of special cases and deviations from standards or odd behavior in all manner of IDE controllers and devices. To the point where the real wizards were the ones who had access to internal data sheets, errata, or reverse engineered firmware from these devices, or otherwise spent countless hours poking at things and reconstructing quirks for themselves, probably bricking a lot of silicon and spinning rust in the process.
But systems and devices are now getting to the point where things don't work that way anymore, silicon power is so cheap and firmware is on everything. The NVMe device for example sets up pretty simple packet-type command queues and sends requests and receives responses for operations - query device information, perform a read or write, etc). It's not quite that simple, there are some quirks and details, but it's quite a lot like writing a client for a server (HTTP, perhaps). I think other device interfaces will evolve toward cleaner simpler models like this too.
One exception to this is GPUs of course. The other thing is with moore's law continuing to slow down there will be increased incentive to move more processing out to devices. It's long been happening with high end network devices, but with technologies like CXL.cache coming soon, I would expect that trend to keep ramping up and come to other accelerators (crypto, AI, even disk).
So.. it's a mix. Things are definitely getting more complex, but AFAIKS the complexity of interacting with hardware is not increasing at a much greater rate than the complexity of interacting with other software. And, as always this complexity is made possible by abstractions and layers and interfaces. It's not clearly exceeding our ability to cope with it.
I saw people become enamored with a Russian anime cat girl on twitter.
This was vapid, consumptive entertainment. Which is perfectly fine, let's just not pretend it's better than the bachelor because science. Replace Chad had a date on love island with Anime cat girl did the science things, and that's about where we're at.