| |
| ▲ | wakawaka28 2 days ago | parent [-] | | >I would dispute this in anything that isn't mostly about string processing and in that case you can always easily grab different string functions, which you should probably do anyway if strings are that important. I'm telling you that I've seen it, in stuff as diverse as video games and robotics. Lots of things use strings as values. It's easy to say "just change everything in millions of lines of code" when you aren't the one who has to make that change. By the way most software does copious amounts of string processing... I think that should be common knowledge, but I guess it isn't. >This doesn't sound like a general purpose statement that applies to anything broadly. You sound like you have zero experience. If your config is in strings, and hundreds of thousands of lines of code already rely on the string-ness of the data, then you just can't make the change easily. >All I'm saying is the the title is wrong and musl doesn't do much to prevent speed in a program. If someone was really trying to optimize, blaming the standard library is not going to get them very far and it's easy to work around, but needing to do that is very rare. I believe the title is accurate. People in performance-sensitive areas gripe about libraries, even standard libraries, quite often. I don't mean to insult you but you're making bold assertions despite clearly lacking the experience to know how things are done in industry generally. | | |
| ▲ | CyberDildonics 2 days ago | parent [-] | | Lots of things use strings as values. To be clear, you're saying that in video games and robotics people are using strings instead of numbers and when that becomes a performance problem you think simple C string functions are to blame? How about not using strings as values? By the way most software does copious amounts of string processing... I think that should be common knowledge, but I guess it isn't. It isn't because it's not true if "copious" is about CPU time. String processing is rarely the bottleneck. I believe the title is accurate Well, it isn't. It's unlikely that musl prevents anyone from making a fast program. It doesn't even make sense. In the off chance anything was a real bottleneck you could bring in something faster and you would want to do that anyway. People in performance-sensitive areas gripe about libraries, even standard libraries, quite often. I have done a lot of optimization and I've never seen the standard library be a problem for exactly what I just outlined. A lot of what you're saying is just "it's a problem because it is, trust me". That isn't evidence or an explanation. As soon as allocation is slow you can avoid allocations (which you should do anyway) or use a different one (which you would do even with a standard libc anyway). If you really have string problems (and not some fake problem like just parsing strings over and over instead of caching values) then you would use an optimized library. The benefit from a regular libc over musl is minuscule compared to the real solutions to optimizing. you're making bold assertions despite clearly lacking the experience to know how things are done in industry generally. Trying for insults doesn't add any sort of technical explanation. To be very clear any program written by someone who says their memory allocator is their bottleneck is something I could speed up by orders of magnitude and the standard library isn't going to matter. | | |
| ▲ | wakawaka28 a day ago | parent [-] | | >To be clear, you're saying that in video games and robotics people are using strings instead of numbers and when that becomes a performance problem you think simple C string functions are to blame? How about not using strings as values? To bring this back to the article, the problem is actually that one library does this worse than others. If you are unfortunate enough to already rely on these functions performing up to a certain standard, then having them become dramatically worse is in fact an issue. Why don't you just not use slow functions? Well, that goes back to my references to refactoring. Even if you could get approval to refactor the stuff, it's still risky and a lot of work. Compare that to just not using an oddball standard library with worse performance... >Well, it isn't. It's unlikely that musl prevents anyone from making a fast program. It doesn't even make sense. In the off chance anything was a real bottleneck you could bring in something faster and you would want to do that anyway. THAT IS THE POINT OF THE ARTICLE TITLE: If you require performance in certain key areas, MUSL may not be acceptable. >I have done a lot of optimization and I've never seen the standard library be a problem for exactly what I just outlined. The article here is literally complaining about a standard library's performance, which is not uncommon in the blog-o-sphere. So, you are ignoring evidence right in your face. People like me are telling you it sometimes matters, and people blog about such problems frequently, but you still aren't getting it. I can only tell you vaguely about codebases I've worked on. I can't tell you where, or show you code, or anything like that. Get used to it. >A lot of what you're saying is just "it's a problem because it is, trust me". That isn't evidence or an explanation. Everything you've said is "It's NOT a problem because I'VE never seen it be a problem!" When the evidence is right in front of your face and people are telling you, yes, it is a problem. Do you think I'm getting paid to share this wisdom with you? If you don't think string processing is a bottleneck, you should consider how many applications are document-based and string-based. Basically, it's a MAJORITY of applications in the world, and I'd put money on that. >As soon as allocation is slow you can avoid allocations (which you should do anyway) or use a different one (which you would do even with a standard libc anyway). More "just refactor bro" or "just use a different library" (the point of the article). Only one of these is likely to be practical in any given situation, especially since MUSL is not the default for most stacks. >The benefit from a regular libc over musl is minuscule compared to the real solutions to optimizing. Bro, if the stats in the article are right (and I have no reason to doubt) the difference is significant (at least numerically). It's easy to tell other people to go do a ton of work to optimize. The radically easier solution is to just not use MUSL if that's your problem. Again, the entire point of the article. >Trying for insults doesn't add any sort of technical explanation. Saying you're inexperienced is not insulting, especially since you're a stranger. You clearly deny having experience with the stuff I'm talking about, which I think is common-knowledge in optimization circles, and then insist on labor-intensive solutions to easily solved problems. Some insulting thoughts have crossed my mind here but I know we've all been inexperienced at some point, so I'm trying to keep it civil to teach you something. >To be very clear any program written by someone who says their memory allocator is their bottleneck is something I could speed up by orders of magnitude and the standard library isn't going to matter. This is youthful arrogance (I can only assume you're young; if not, you at least haven't matured in your career). It's not always possible to do such optimization, from either a technical perspective or a pragmatic one. Most people do not have authority to go on an optimization binge across their codebases, assuming the penalty is even paid by their own code (it often comes from upstream libraries!). Even if you did have the authority, expertise, and time to do the optimization, it could be a horrible idea and introduce a LOT of potential bugs. I like the idea of MUSL, and wish the project well. I may even use it for something one day. But none of this makes their performance better. It may be that getting better performance would compromise their other objectives, such as simplicity. | | |
| ▲ | CyberDildonics a day ago | parent [-] | | If you are unfortunate enough to already rely on these functions performing up to a certain standard, then having them become dramatically worse is in fact an issue. There are a few problems here. The first saying that anything is dramatically worse. The second is thinking that nothing can be changed. The third is thinking that there are lots of programs out there that spend all their time in C string functions yet nothing can be altered except for linking in a different standard library. I can't tell you where, or show you code, or anything like that. Get used to it. I didn't expect at any point that you to be able to back up what you are saying with examples. Everything you've said is "It's NOT a problem because I'VE never seen it be a problem!" That couldn't be further from the truth. I'm saying it isn't a problem because the problems are easily fixable and musl doesn't prevent them from being fixed. You hallucinated a quote and made up something completely different in your head. If you don't think string processing is a bottleneck, you should consider how many applications are document-based and string-based. Basically, it's a MAJORITY of applications in the world, and I'd put money on that. You think these programs are bottlenecked by the C-string functions in their standard library? That's a bold claim. Why would a program completely dependent on strings even use C string functions in the first place? You have to scan to a newline to find the length, they work with ascii and they are known to be incredibly insecure. What you're saying doesn't make sense. You clearly deny having experience with the stuff I'm talking about, I deny that there are programs that can only be sped up by switching to a different C library and nothing else, since that's nonsense. just not use MUSL if that's your problem. People can do whatever they want, all I've ever said is that musl doesn't prevent anyone from making a fast program. That's it. Saying you're inexperienced is not insulting, I'll take your word for it because you seem extremely inexperienced at optimizing, especially if you think making fast software should include leaning on C strings and having memory allocation show up on your profiler. This is youthful arrogance (I can only assume you're young; if not, you at least haven't matured in your career). You can go for the insults and try to be patronizing again, I expect that as the last resort of someone frustrated that repeating their claim isn't taken as evidence. I explained a lot in detail about why musl isn't going to prevent anyone from writing fast software because I've done it over and over. You seem to be saying that you can speed up legacy programs somewhat that weren't made well in the first place with a faster libc and I'm sure that's true, but it has nothing at all to do with the premise the musl prevents a program from being fast or even is much of a bump in the road. The speed ups from a more optimized libc are percentage points shaved off the the times where you actually use it. Using better string functions, minimizing allocations and paying attention to memory access patterns are going to be order of magnitude changes. Minimizing allocations is going to be at least 7x on a single core, better memory access patterns are going to be 20x-25x. You don't have any evidence or explanation that musl prevents someone from writing fast software, which is the title and the title is wrong. | | |
| ▲ | wakawaka28 a day ago | parent [-] | | >There are a few problems here. The first saying that anything is dramatically worse. The second is thinking that nothing can be changed. The third is thinking that there are lots of programs out there that spend all their time in C string functions yet nothing can be altered except for linking in a different standard library. 25% slowdown can be dramatic for some applications. Secondly, I didn't say that nothing can be changed. I said that change is expensive. Thirdly, I think linking another library is probably acceptable to get an easy 25% speedup! This problem was probably discovered by somebody saying "Why is this shit so slow when I link with MUSL?" Regarding "Nothing can be altered except for linking" -- There are many such cases. This especially happens with upstream code. If you use a library that you aren't willing or able to fork, you have to deal with its limitations. This can happen for open-source projects, or for private commercial projects. >You hallucinated a quote and made up something completely different in your head. I summarized your whole position in an ironic quote to show you how dumb it is. I'm sorry you don't see how you come off. Calling my rhetoric "hallucination" is laughable. I could swear I'm arguing with a bot. >I'm saying it isn't a problem because the problems are easily fixable and musl doesn't prevent them from being fixed. Your fix suggestion amounts to calling for a huge refactoring, as I said. MUSL does not prevent you from doing that, but it's easier to just not link MUSL if it's causing problems for you. >You think these programs are bottlenecked by the C-string functions in their standard library? That's a bold claim. Why would a program completely dependent on strings even use C string functions in the first place? You have to scan to a newline to find the length, they work with ascii and they are known to be incredibly insecure. What you're saying doesn't make sense. Performance-sensitive programs and libraries are often written in C. C-string representation is widely used by all programming languages, which are usually written in C or C++ (which uses C). >I deny that there are programs that can only be sped up by switching to a different C library and nothing else, since that's nonsense. This statement is the real nonsense. Again with the "I've never seen it, so it can't exist" bullshit. >People can do whatever they want, all I've ever said is that musl doesn't prevent anyone from making a fast program. That's it. No, that's not all you've said. You said the title is wrong. You said (roughly speaking) that the choice of standard library is never a decision point for performance. The title of this article may be a bit exaggerated, but there's a clear example of poor MUSL performance in the article. It's also not JUST slow string functions, it's slow memory allocation too. What's next, you gonna say you've never seen a program that needs lots of memory allocation? Or that I should go fork some upstream project to work around MUSL's limitations? >You can go for the insults and try to be patronizing again, I expect that as the last resort of someone frustrated that repeating their claim isn't taken as evidence. I explained a lot in detail about why musl isn't going to prevent anyone from writing fast software because I've done it over and over. You can keep saying it over and over and it won't be any more true. It's true that I'm making claims and you're not accepting them. What you should ask yourself is what I have to gain by making these claims. The answer is nothing. I'm beginning to think you're a troll. Your username certainly suggests it. >You seem to be saying that you can speed up legacy programs somewhat that weren't made well in the first place with a faster libc and I'm sure that's true, but it has nothing at all to do with the premise the musl prevents a program from being fast or even is much of a bump in the road. I am CLEARLY saying that. Linking MUSL to any program that heavily uses the slow functions will make it slower. Since MUSL is not the default for most software, this will be observed as totally unnecessary and inexcusable performance degradation. If you're trying to build the fastest version of some software, you should use the fastest libraries. Your position seems to be that the title is wrong because it is theoretically possible to make MUSL-dependent programs fast according to some unstated performance metric, so the title is necessarily wrong. What you don't see is that no matter what performance metric you choose, if I wrote the program to be fast with MUSL, it would be EVEN FASTER with a faster library. It might be "fast enough" for somebody with MUSL alone. But if that somebody cares about performance (like the title says) then they will use the fastest library they can. They won't refactor all their code to make MUSL work faster. Sometimes the objective of caring about performance is to have literally the fastest thing possible, not just "fast enough". >You don't have any evidence or explanation that musl prevents someone from writing fast software, which is the title and the title is wrong. The title doesn't say that MUSL will stop you from writing fast software. I never said that either. The title says "Don't use MUSL if you care about performance." But keep burning that straw man bro. I'm done with this bullshit conversation. | | |
| ▲ | CyberDildonics 15 hours ago | parent [-] | | 25% slowdown can be dramatic for some applications. What you keep forgetting is that's 25% of the part that you're actually using. You keep avoiding and denying that for a program where any sort of speed matters you just aren't spending any of your time hitting the C standard library. If a program is slow because of the C standard library and it needs to be faster, someone messed up a long time ago. That isn't the C libraries fault. You can squeeze a little more out of it if you have find a more optimized library, but it's all a drop in the ocean compared to how much faster it would go by doing basic real optimizations. Performance-sensitive programs and libraries are often written in C. C-string representation is widely used by all programming languages, which are usually written in C or C++ (which uses C). You can say that, but really it's almost all C++ and people avoid C strings for exactly why I outlined in detail. You don't have length up front, it's all ascii, you're dealing with pointers to arbitrary runs of bytes, etc. This is not good for memory access patterns, dealing with lots of characters at one time, dealing with unicode, minimizing memory allocations etc. It's true that I'm making claims and you're not accepting them. That is true that you are making lots of claims and that I'm not accepting them, because you don't have any evidence or explanations and they don't make sense. All I've said is that MUSL doesn't prevent someone from making fast programs and you barely have even confronted that, let alone explained how it isn't true. Linking MUSL to any program that heavily uses the slow functions will make it slower. Any program that is hammering the the C standard library can be sped up by orders of magnitude and 25% is nothing. Again, lifting memory allocations will speed something up by 10x, so that 25% isn't going to matter anymore because it's 25% of something that isn't even going to show up on a profiler, let alone be a bottleneck. Your position seems to be that the title is wrong because it is theoretically possible to make MUSL-dependent programs fast according to some unstated performance metric I think you mean it's trivially possible according to the detailed explanation I gave from a lot of experience optimizing. Sometimes the objective of caring about performance is to have literally the fastest thing possible, not just "fast enough". 25% better might be fast enough for you, I like speeding up programs by 100x by changing to C++ instead of C and focusing on the optimizations that matter. The title says "Don't use MUSL if you care about performance." I use musl and I care a lot about performance. It doesn't matter because has no bearing on how fast my programs are. I'm done with this bullshit conversation. I'm sure it seems that way when someone doesn't accept the same claim over and over without any actual explanation or evidence. Saying the same thing and getting more upset is not an effective way to make your point. You need real information, not insults and fake quotes. | | |
| ▲ | wakawaka28 11 hours ago | parent [-] | | I awoke today with renewed energy to deal with your nonsense, and I think after reading this comment it deserves a (hopefully) short reply. >I use musl and I care a lot about performance. It doesn't matter because has no bearing on how fast my programs are. This is the crux of the matter. You clearly have some investment in MUSL, that much has been apparent all along. If you actually USE it, which I'm sure you do, then you are not using the fastest possible library. Regardless of your skill, simply switching to a faster library will make a program faster. Sometimes, that's what is needed. We JUST want to find easy ways to make code as fast as possible. We aren't looking to rewrite the world. I don't have any investment in MUSL. I wish the project well, but if it's not the fastest library then it will necessarily be unsuitable for some applications. >What you keep forgetting is that's 25% of the part that you're actually using. First off, I didn't forget shit. There are surely programs for which the penalty is actually 25% or close to it. The penalty can actually be far worse than that due to algorithmic complexity issues. Secondly, it is quite possible that one could use the standard library almost exclusively. Thirdly, any performance drop could be significant. >You can say that, but really it's almost all C++ and people avoid C strings for exactly why I outlined in detail. You don't have length up front, it's all ascii, you're dealing with pointers to arbitrary runs of bytes, etc. C strings are used extensively in C++. Again you prove how inexperienced you are. >This is not good for memory access patterns, dealing with lots of characters at one time, dealing with unicode, minimizing memory allocations etc. Keep deflecting with bullshit that is irrelevant to the choice of library, and that can't be changed but for massive refactoring. >That is true that you are making lots of claims and that I'm not accepting them, because you don't have any evidence or explanations and they don't make sense. There's only so much evidence and explanation I can provide to strangers on the internet. Then there is also the level of evidence that I can provide, such as other blog posts, that I don't feel like providing. A lot of the things I've said are true a priori (assuming some simplifications), such as the fact that a slower library will always be worse for performance than a faster library. If MUSL is measurably slower than others, then it can be a problem. >Any program that is hammering the the C standard library can be sped up by orders of magnitude and 25% is nothing. Again, lifting memory allocations will speed something up by 10x, so that 25% isn't going to matter anymore because it's 25% of something that isn't even going to show up on a profiler, let alone be a bottleneck. As I've said many times, rewriting software is not always on the table. Even minor changes may be forbidden or burdensome for various reasons. What you're talking about is a redesign, that may not be applicable to all cases anyway. >>Your position seems to be that the title is wrong because it is theoretically possible to make MUSL-dependent programs fast according to some unstated performance metric > >I think you mean it's trivially possible according to the detailed explanation I gave from a lot of experience optimizing. Right, your position is definitely that making these changes is "trivial"... I threw in "theoretically" because I interjected my own knowledge that these optimizations are often only theoretically possible, and can't be done for many practical reasons. My wrong statement of your position made it more defensible than it actually is. >25% better might be fast enough for you, I like speeding up programs by 100x by changing to C++ instead of C and focusing on the optimizations that matter. I don't want to get off on another tangent but you are trivializing and exaggerating a lot of stuff in this one statement. Changing languages and altering the code is not an easy win, and might actually trigger a performance setback. Switching to a faster library is a relatively easy win. >Saying the same thing and getting more upset is not an effective way to make your point. You need real information, not insults and fake quotes. I've made my point already, you just haven't accepted it. I assume you are either incapable of understanding (perhaps temporarily), or have unstated biases as I pointed out due to being a MUSL enthusiast or contributor. You're not convincing me either way. My position is that people who care about being as fast as possible should use the fastest available library, which clearly isn't MUSL. There may be other valid reasons to use MUSL, and it may be "fast enough", but other libraries are yet faster. This is how I see your argument so far: - MUSL is fast enough, trust me bro. - Ok, maybe someone measured some functions to be slower, but everyone knows that you shouldn't be using the STANDARD LIBRARY heavily. Nobody has ever used strings or memory allocation that heavily, and if they did then they are doing it wrong (even if other libraries provide adequate performance for them). - If you have a problem with this, you just need to do some trivial optimizations, or change languages to C++. It's SUPER EASY (at least for elite MFers like myself). - Because rewriting the code to compensate for MUSL performance is always on the table, it's never reasonable to say that MUSL is causing a performance problem. I only added a slight amount of emphasis. You've been pretty close to that bombastic in the whole exchange. It's ridiculous, and I think you are smart enough to know better but admitting that you are wrong is beyond the pale. Instead of wasting my time, how about applying those elite optimization skills you claim to have to the MUSL code to make it faster. Then you will be able to write a blog like "Don't use glibc if you care about performance" and argue with people on HN if you want. By the way, I didn't write this blog post, and I don't have any other conflicts of interest such as being a glibc developer, so don't start up with that shit either. | | |
| ▲ | CyberDildonics 6 hours ago | parent [-] | | C strings are used extensively in C++. Again you prove how inexperienced you are. You can try to be patronizing if you want, but this doesn't make sense with you not understanding memory access patterns. If someone uses C++ they will use C++ strings. Have you used C++? It works well and it has been around for 40 years, you should give it a try. Keep deflecting with bullshit that is irrelevant to the choice of library, and that can't be changed but for massive refactoring. You painting yourself into a corner has nothing to do with a C library being a few percentage points slower. This is not a general scenario, it's something you are dealing with because you can't optimize C strings. If you think memory access patterns are 'bullshit' you haven't done much optimization. That's everything in modern optimization. If there is an expert somewhere around you, please talk to them so you can get up to speed on modern optimization. Minimizing allocations is table stakes, memory access is the meat. If you have any examples on github of things you think "can't" be optimized, go ahead and link it and tell me what a profiler shows, and I will explain what to do. I've made my point already, you just haven't accepted it. You made your claim, you haven't had any evidence or explanation, that's how it works. You say the same thing over and over and get more upset, but that isn't evidence. Show me where musl prevents someone from writing a fast program. Insults and hallucinated quotes aren't a good foundation for proving your point. If you have to pretend that someone said something different, then maybe you aren't really making sense. how about applying those elite optimization skills you claim to have to the MUSL code to make it faster. Why would I do that when I don't use the C library for performance sensitive programs? You never seem to be able to confront this. The stuff made 50 years ago isn't the fastest possible stuff. It's still pretty fast and if you want something faster, do something else. It's not that complicated but it seems to really upset you. I don't have any other conflicts of interest such as being a glibc developer, so don't start up with that shit either. No one said anything about that, I think you're hallucinating or predicting something that never happened. |
|
|
|
|
|
|
|
|
