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“Clean” code, horrible performance

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Re: “Clean” code, horrible performance

#531

Post by noobermin »

yashap wrote: post #263
mabbo wrote: post #179

I think the author is taking general advice and applying it to a niche situation. > So by violating the first rule of clean code — which is one of its central tenants — we are able to drop from 35 cycles per shape to 24 cycles per shape Look, most modern software is spending 99.9% of the time waiting for user input, and 0.1% of the time actually calculating something. If you're writing a AAA video game, or high perfo…

100%, I’ve done tonnes of (backend) performance optimization, profiling, etc. on higher level applications, and the perf bottlenecks have never been any of the things discussed in this article. It’s normally things like: - Slow DB queries - Lack of concurrency/parallelism - Lack of caching/memoization for some expensive thing that could be cached - Excessive serialization/deserialization (things like ORMs that create…

To be fair to OP, does anything about your current paradigm even allow you to evaluate his claims? Is your code even in a form that you can for example remove polymorphism and use simple arrays of data you want to work over?

You can of course only optimize what you are looking to optimize. I am not surprised (honestly) that some engineers do not realize they are in fact primed for the kind of things they will find based on what they are looking by the mere choice of where they want to look.

Re: “Clean” code, horrible performance

#532

Post by xupybd »

jiggawatts wrote: post #510
xupybd wrote: post #495

Earlier quoted context omitted.

Sure that makes a lot of sense, I'm sorry for my bad assumptions, but that drives my point home even more. The problem is not related directly to your performance on the hardware. It's an additional cost from the business environment. License costs can drastically alter where your efforts are best spent. I'd imagine there are times where you might be better off pulling huge chunks of data out of the database to proce…

> CPU cycles are cheap But people aren't. Any code that "makes people wait" is wasting people's time. The only way to make code take less time is to optimise it, because capacity != latency. You can't get a 20 THz processor. You can buy more capacity, but you can't buy more speed! At FAANG scale, it's common to hire "top" developers at hugely expensive annual total comp to tune stdlib code like "string" for just 1-2%…

>I can't think of a typical business scenario where compute and/or associated per-core-licensing costs can be blindly disregarded with a flippant statement like "developers are expensive and infrastructure is cheap".

Say you're a small business with an in house server rack. Not a software company but say a manufacturing business. Not enterprise scale, smaller. You have 1 development resource. It turns out the ETL server is overloaded and it's causing the reports that run on the same server to run slow. You could get the developer to spend a few weeks porting the legacy system to faster modern option to speed up the ETL and maybe improving some of the reports. But it would be far cheaper to buy in another server for $3k and have the developer spend less than half a day moving the ETL onto the fresh server.

Re: “Clean” code, horrible performance

#533

Post by xupybd »

loup-vaillant wrote: post #423
xupybd wrote: post #219

>It simply cannot be the case that we're willing to give up a decade or more of hardware performance just to make programmers’ lives a little bit easier. Our job is to write programs that run well on the hardware that we are given. If this is how bad these rules cause software to perform, they simply aren't acceptable. That is not our job! Our job is to solve business problems within the constraints we are given. No…

> CPU cycles are much cheaper than developer wages. CPU cycles are cheap. Dev time is expensive. User time is sacred . https://www.lesswrong.com/tag/scope-insensitivity

>User time is sacred.

Why? What if the user is a machine operator? He is standing around waiting for the machine to finish it's current cycle. As long as he can get his data entry done in the time he is waiting it costs the business nothing.

Re: “Clean” code, horrible performance

#534

Post by iamcreasy »

mabbo wrote: post #179

I think the author is taking general advice and applying it to a niche situation. > So by violating the first rule of clean code — which is one of its central tenants — we are able to drop from 35 cycles per shape to 24 cycles per shape Look, most modern software is spending 99.9% of the time waiting for user input, and 0.1% of the time actually calculating something. If you're writing a AAA video game, or high perfo…

> Look, most modern software is spending 99.9% of the time waiting for user input, and 0.1% of the time actually calculating something.

This talk(Preventing the Collapse of Civilization) by Jonathan Blow disagrees with you.

Link: https://www.youtube.com/watch?v=ZSRHeXYDLko

Re: “Clean” code, horrible performance

#535

Post by l33t233372 »

kaba0 wrote: post #271
morelisp wrote: post #248

Earlier quoted context omitted.

> You ain’t (hopefully) loading your whole database into memory I've basically built my career for the past decade by pointing out "yes, we can load our whole working set into memory" for the vast majority of problems. This is especially true if you have so little data you think you don't have CPU problems either.

Databases are often not used by a single entity, so while I am very interested in your experiences, I think it is a great specialization for certain problems, but is not a general solution to everything. All in all, I fail to see how it disagrees with my points.

> All in all, I fail to see how it disagrees with my points.

I didn’t see any part of the comment that implied it did

Re: “Clean” code, horrible performance

#536

Post by noobermin »

p1necone wrote: post #293
yashap wrote: post #263

Earlier quoted context omitted.

100%, I’ve done tonnes of (backend) performance optimization, profiling, etc. on higher level applications, and the perf bottlenecks have never been any of the things discussed in this article. It’s normally things like: - Slow DB queries - Lack of concurrency/parallelism - Lack of caching/memoization for some expensive thing that could be cached - Excessive serialization/deserialization (things like ORMs that create…

Casey Muratori knows a lot about optimizing performance in game engines. He then assumes that all other software must be slow because of the exact same problems. I think the core problem here is that he assumes that everything is inside a tight loop, because in a game engine that's rendering 60+ times a second (and probably running physics etc at a higher rate than that) that's almost always true. Also the fact that…

The fact that you think that "everything is inside a tight loop" doesn't apply to all code today already shows your own model of code is broken because you believe the syntactic sugar modern programming languages and paradigms provide is actually reality. If everything wasn't in a loop, your program would halt once you're done with whatever you're calculating. Just because you have things like callbacks and things feel lazy doesn't mean that things do not really operate in a loop on a deep level, of course they do. You just are insulated from it because you write hooks only and such and you don't actually see the loop.

Believe it or not, callbacks are not like interrupts, there is a loop somewhere that checks the status of something and then runs the callback. All computer software today involve things that run in loops, you just don't see it. Web browsers do it! Of course they do.

Moreover, he didn't contrive his example, he said that he in fact used a textbook example used by the advocates for polymorphism and such.

Re: “Clean” code, horrible performance

#537

Post by bccdee »

p1necone wrote: post #293
yashap wrote: post #263

Earlier quoted context omitted.

100%, I’ve done tonnes of (backend) performance optimization, profiling, etc. on higher level applications, and the perf bottlenecks have never been any of the things discussed in this article. It’s normally things like: - Slow DB queries - Lack of concurrency/parallelism - Lack of caching/memoization for some expensive thing that could be cached - Excessive serialization/deserialization (things like ORMs that create…

Casey Muratori knows a lot about optimizing performance in game engines. He then assumes that all other software must be slow because of the exact same problems. I think the core problem here is that he assumes that everything is inside a tight loop, because in a game engine that's rendering 60+ times a second (and probably running physics etc at a higher rate than that) that's almost always true. Also the fact that…

Bob Martin has made a real effort to tie himself to the specific phrase "clean code." If the author of this article had referred to clean code without using quotation marks, or talked about managing software complexity using any other term, you'd be right, but I think he's specifically talking about Bob Martin's "Clean Code" and the school of object-oriented philosophy that cleaves close to his beliefs.

Re: “Clean” code, horrible performance

#538

Post by cratermoon »

e28eta wrote: post #487
yashap wrote: post #263

Earlier quoted context omitted.

100%, I’ve done tonnes of (backend) performance optimization, profiling, etc. on higher level applications, and the perf bottlenecks have never been any of the things discussed in this article. It’s normally things like: - Slow DB queries - Lack of concurrency/parallelism - Lack of caching/memoization for some expensive thing that could be cached - Excessive serialization/deserialization (things like ORMs that create…

Author could use a little more memoization in his example, but I suspect that breaks some of the simplicity of his argument. If shape Area is computed often enough that you care about inlining the calculation, why not compute & store it every time the height / width change. That’d be easy enough in an architecture based on information hiding, and might illustrate a legitimate engineering trade-off between those archi…

Right? His Area() function does the calculation from the scratch every call. Either a) make the Shape immutable and calculate area once, at create time, or have the mutator functions recompute the area when they are called. At that point Area() just returns an f32, and the compiler can do all kinds of optimizations.

Re: “Clean” code, horrible performance

#539

Post by _aavaa_ »

kaba0 wrote: post #166
MikeCampo wrote: post #158

Earlier quoted context omitted.

Just because you haven't been exposed this issue doesn't mean it doesn't exist. "the real situation", "no one", "in real projects", "never pop up"...give me a break lol.

One can reasonably well guess/know the expected input sizes to their programs. You ain’t (hopefully) loading your whole database into memory, and unless you are writing a simulation/game engine or another specialized application, your application is unlikely to have a single scorching hot loop, that’s just not how most programs look like. If it is, then you should design for it, which may even mean changing programmi…

But the point isn't that just the scorching hot loop is 20x slower, but that this penalty is paid everywhere. And it won't show up in profiling since there isn't a hotspot, it's death by 100 cuts.

Re: “Clean” code, horrible performance

#540

Post by charles_f »

> Prefer polymorphism to “if/else” and “switch”

Wtf? First time I hear about this one, and it sounds like a dumb dogma.

> It’s a base class for a shape with a few specific shapes derived from it: circle, triangle, rectangle, square. We then have a virtual function that computes the area.

Quite literally the first and simplest example for why you should prefer composition over inheritance[^1] (that and ducks and chickens).

Good strawman. I am unconvinced.

1: https://en.m.wikipedia.org/wiki/Composition_over_inheritance

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