> The things you can do between fork and exec are sometimes underestimated. Off the top of my head, you can call dup2(), you can set a process group id, probably a few other things.
What do you mean underestimated? You can do anything between fork and exec; there are no limitations.
That's not true. Just one example, if you do anything with threads you are pretty screwed. For example if another thread holds a mutex at the time of fork(2), and you also want that mutex.
You can create threads in forked children before exec. Nothing in the kernel prevents you from invoking clone().
You're talking about libc (glibc) implementation details now; userspace programs running on the Linux kernel do not have to be implemented in C or use glibc's primitives. Your earlier comment I initially replied to was talking about kernel syscalls. Forked processes are free to invoke any syscall they want, not just dup2 or a handful of others.
I'm not talking about glibc implementation details. I'm talking about how mixing fork(2) with threads creates harmful race conditions.
The forked child has only 1 thread in its process. If the parent's threads are holding a lock or are in the middle of mutating a shared data structure, you're fucked, because those threads are no longer running in your child's copy of the address space and will not finish their work. This issue is fundamental to how threads work and what fork(2) does.
Again, you're talking about userspace now. Not kernel-imposed constraints. A userspace program is always free to deadlock itself; fork doesn't change that.
This means if the program is multi threaded, you cannot rely on calling malloc in the child, because at the time of the fork another thread could have happened to be inside malloc doing manipulations on the global heap.
Which means, practically speaking, "don't allocate memory between fork and exec".
If you want to be overly literal as you have been, you can call mmap and it will give you new pages, but who is really doing that? Not the random shared library code you might want to call into. Hell, even a lot of libc calls malloc.
Which means it's not safe to do a random library call between fork and exec.
See where I'm going with this? That's if your program is multi threaded. If it isn't, these things are most likely fine.
I never said it was a kernel imposed constraint. It remains unsafe behavior, and frankly you'd be stupid to ignore it if you want to write a stable multi threaded program. In colloquial shorthand, you can't do it.
Signal safety is not the same as this, but similar. I believe posix specifies what is signal-unsafe to be overly broad. But the unsafety isn't an illusion -- it's an emergent property from something being a bad idea given the primitives at work, there are broad categories of bugs that are easy to introduce due to the way it works. So for signals, posix declares a bunch of ill advised things to be undefined, and with good reason. This is an analogous scenario.
You're talking about libc design choices, not constraints imposed by the kernel. To the kernel, a post-fork pre-exec process is just any old process. GP was suggesting post-fork processes were constrained in the syscalls they could invoke; they are not.
I did not say they are constrained in what syscalls they can make, as if some nanny at the syscall entry point will punish you for doing wrong. I said that it interacts poorly with threads due to inherent race conditions. See the other comment.
Literally nothing in that comment mentions or discusses threads.
> I did not say they are constrained in what syscalls they can make
You wrote: "The things you can do between fork and exec are sometimes underestimated. Off the top of my head, you can call dup2(), you can set a process group id, probably a few other things."
Those are all syscalls. You can also invoke any of the other ~hundreds of syscalls linux exposes, not only dup2, setpgid, and a "few" others.
I recommend at least skimming the paper as it covers this. But essentially you can’t just inject a call at a random point in code to start being a zygote. It’s something you have to plan up front as to the exact point you’re going to fork and that you’re going to do it at the start of program before any threads have started or any files are open and before any locks have been acquired. It’s basically all the challenges of invoking fork at arbitrary points in time.
The reason to do a zygote in the first place could be solved with alternative special APIs that are safer and harder to misuse. But we have fork so there’s not as big of a demand despite the warts.
sure it's not a given, but I certainly am not confident enough that it won't happen to bet my money in it, which I would automatically be doing if it was admitted to the SP500
Firstly, I think 0.15% might be significantly lowballing. Other commenters I've read trying to low ball it suggested 0.5%, which matches up with my calculations - this IPO is allegedly $1.5T on the total amount, and 25% is up for sale, making $375B. The S&P 500 market cap is $69T, which puts the IPO at 0.54%.
In addition, that's just the initial IPO free float value, and other shareholders will be free to shed their shares after IPO (and presumably, that's where the bulk of index investment funds will actually buy from), so the free float will be higher, pushing up that share even higher.
Sure, in terms of overall market fluctuations, 0.5% is significantly less than a typical day of market volatility, but on the other hand in terms of my current portfolio, as a dollar amount that's significantly more than my monthly expenditure when I'm not vacationing. I don't particularly want to be funding Elon's exit strategy when I already believe it to be a scam. Thanks to S&P's decision, about 25% of my investments are safe, but approximately 60% of my funds are linked to FTSE World indicies, which is changing the rules.
As I stated in another post, this is just a cheap stunt to force passive investors to prop up the price before it has a chance to settle. The majority of IPOs settle on a price below the IPO price in the months afterwards, and never before have we seen an IPO with such a high P/E ratio. This is literally unprecedented, and the sensible thing to do would be to stick to the old rules to allow the market time to discover the true value before inclusion in the indices. At the moment, the valuation is just a number in Elon's head rather than a fair market valuation. Forcing index-following funds to purchase it at the artificially high price is reckless at best and profiteering at worst.
In addition, it's not just 0.5%. It's 0.5% now, and then the same for Anthropic, and then the same for OpenAI, then all the other IPOs in the future. To put that into perspective, most investors would baulk at 0.38% TER for a passive fund and move to 0.12% TER. 0.5% isn't nothing.
SpaceX is not worth $1 trillion, when most of that valuation is based on xAI being worth far more then their already dominant position in the space launch business.
> EDIT: I have been shadowbanned, again, by HN. I check this by opening this thread in a private tab, not logged in, and notice my most recent comment is not visible.
> I wasn't personally insulting nor aggressive in any comment I have made. I didn't spread disinformation. This thread is inherently political by nature, and I have been objective.
> It just goes to show, even here on HN, if you don't stick to the "THIS SIDE GOOD THAT SIDE BAD" narrative, your voice WILL be restricted.
> Again, RIP Marjane, you taught me a lot about Iran and the world.
You're not shadow banned, but comments peddling objectively false conspiracy theories and whining about downvoting do not play well here.
They made it political. We were just having a non-political thread about an author famous for critiquing the Iran government. Then they made it political.
This isn't fringe stuff, it's well known and documented, I would have thought most people commenting on a post about Iran would know this history, perhaps I can help you out:
"Conspiracy" Theory: "CIA/MI6 coup of 1953 that overthrew Iran's democratically elected government to protect Western oil interests"
Evidence: https://en.wikipedia.org/wiki/1953_Iranian_coup_d%27%C3%A9ta...
"On 19 August 1953, Prime Minister of Iran Mohammad Mosaddegh was fired by Mohammad Reza Pahlavi, the Shah of Iran .... It was instigated by the United Kingdom (MI6), under the name Operation Boot and the United States (CIA), under the name TP-AJAX Project or Operation Ajax. A key motive was to protect British oil interests in Iran after Mosaddegh nationalized the country's oil industry."
If you find any evidence that says CIA/MI5 were not behind the coup of a democratically elected government to protect Western oil interests, please let me know, I'm very interested in this topic.
"Conspiracy" Theory: "verifiable institutional actors with control over media outlets, public figures, and politicians -pointing to a systematic, decades-long negative framing of Iran"
Evidence:
State Department records list CIA “Political Propaganda” work in the TPAJAX files.
https://history.state.gov/historicaldocuments/frus1951-54Ira...
"CIA Confirms Role in 1953 Iran Coup" (from the National Security Archive)
https://nsarchive2.gwu.edu/NSAEBB/NSAEBB435/
"American and British involvement in Mosaddeq's ouster has long been public knowledge, but today's posting includes what is believed to be the CIA's first formal acknowledgement that the agency helped to plan and execute the coup."
Since then, there is substantial evidence Western/U.S. coverage and official discourse has repeatedly framed Iran through threat, extremism, nuclear danger, terrorism, and regime instability. Rather than me spamming links, I will just say this evidence is very easy to find and read. If you have any evidence to the contrary, please present it.
"Conspiracy" Theory: "you almost never read anything good about Iran?"
Evidence: Go to the websites of major Western outlets such as BBC News, The Guardian, NYT - search for "Iran" and look at the first 50–100 headlines.
Then categorise them into things like:
War/conflict
Nuclear program
Sanctions
Human rights
Economy
Tourism
Culture
Science
Daily life
Objectively, you will find mostly negative or negatively framed stories. If you find any evidence to the contrary, I'm very interested.
Are there any other "conspiracy theories" I have mentioned that are "objectively false"?
"I have been shadowbanned, again, by HN. ... It just goes to show, even here on HN, if you don't stick to the 'THIS SIDE GOOD THAT SIDE BAD' narrative, your voice WILL be restricted."
That's an objectively false conspiracy theory. We don't even need to touch the Iran ramblings.
Me: "here on HN, if you don't stick to the 'THIS SIDE GOOD THAT SIDE BAD' narrative, your voice WILL be restricted."
1) I open a private window and view this thread - there are five total posts by me.
2) when logged in, there are seven posts - this is what's called "shadow banned"
3) in the private tab, one of my posts is flagged, it's specifically the one where I say "this is what happens in our world when you don't uncritically and simplistically stick to one side bad or one side good"
Your response: "You're not shadow banned"
HN response to my post: [flagged]
--------------
You: "objectively false conspiracy theories"
Me: "CIA/MI6 coup of 1953 that overthrew Iran's democratically elected government to protect Western oil interests"
Title: "CIA/MI6 coup of 1953 that overthrew Iran's democratically elected government to protect Western oil interests"
In the opening paragraph:
"On 19 August 1953, Prime Minister of Iran Mohammad Mosaddegh was fired by Mohammad Reza Pahlavi, the Shah of Iran .... It was instigated by the United Kingdom (MI6), under the name Operation Boot and the United States (CIA), under the name TP-AJAX Project or Operation Ajax. A key motive was to protect British oil interests in Iran after Mosaddegh nationalized the country's oil industry."
Your response: "ramblings"
You're really not very good at being faced with objective facts that interfere with your worldview, whether it's HN or Iran.
My take from the SCW interview is that the Mythos harness isn't all that important and the author thought it would be even less important with future models. But maybe I misremember.
Anthropic has a vested interest in downplaying the harness relevance. In my experience harness really matters. More capable models are great, but current models are enough if you put some engineering effort into the harness.
It seems like Buettner in particular had a bunch of for-profit business ventures tied up in blue zone marketing bullshit, so that is a sort of non-academic motivation to keep the music going.
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