The Most Successful Idea in Computer Science

[@griffenmorrison2560]

Getting this compliment in early in hopes you see it before it gets buried. Your videos have demystified the fundamental parts of computers I had thought I wasnt smart enough to understand. You have given me the confidence to feel like I can tackle any computer challenge I come across. I ravenously wait for your next video after each one is released. Thank you!

[@hard.nurtai4209]

yeah he really is influential

[@levipalait683]

Same here

[@SweepAndZone]

He's amazing. A good human

[@VideosViraisVirais-dc7nx]

Omg 😮 This Guy is German.

[@u_u_u_2921]

I think the key reason for the ease of explanation is a real understanding. If one can't explain something in simple words one just really understands the topic.

[@IngPleb]

Once again, the production and educational quality are absolutely marvelous! Even though I’ve already read about many of these things, the visuals always solidify my knowledge and somehow excite me because I get to live in this wonderful era of computing. Please keep it up.

[@CoreDumpped]

Will do! Thanks for the support!

[@jaison9]

​@@CoreDumppedwhere are you from? Please keep the brilliant work

[@eduimaji]

@@CoreDumpped i stack with the "cache mapping" especially the h/w implementation. could you explain it, please? thanks.

[@MathCuriousity]

@@CoreDumpped hope you do a video accessible to noobs like me concerning what an API is (focusing on non-web apis)

[@bodycowlin]

I hardly ever comment on anything, but the quality here is insane. Not just the graphical quality either, the quality and accessibility of the information blows my mind. Like others have said you are a wizard at demystifying the concepts you explain. I come from a mechanical engineering background but feel as though even I can grasp these concepts now. Keep up the good work! You've made a lifelong fan here.

[@gabrielbonfim1]

Man, I recentely commented the same thing as you, I never comment on youtube videos, but this guy is simply extraordinary, I had to share the video with everyone I know. It just blows my mind how can someone teach something so clearly.

[@AlgoRhythmsWithAyush]

This is truly amazing, as a low level enthusiast, I now know what processes really look like at the low level, you really explained the concepts in one of the most beginner friendly ways possible. Keep going George! looking forward for the next episode.

[@fooBarFalan]

I wish these videos existed back when I was taking OS course. Simply amazing.

[@_dnL]

yea me too

[@MyMax1919]

The Linux scheduler code part was neat, I would love to see more real-world code snippets in future videos!

[@_dnL]

yes, love real world examples :D

[@MukundNivas]

I really enjoyed watching this! Thank you for making this. I would love to do some additional reading on this, would it be possible to reference books/articles that you referenced through while making this video? Thanks man.

[@CoreDumpped]

For Operating Systems theory: "Operating System Concepts" by Silverschatz. For low-level stuff in general: "Computer systems a programmer's perspective" by Bryant, O'Hallaron.

[@EduardoTardinCosta]

Well done! My suggestion: after your video about threads, a video about forks and pipes to explain how process "talk" to each other.

[@Piyush-bm6ho]

@CoreDumpped your creations are excellent. I'm waiting for video of Virtual memory, mapping of virtual memory to physical memory, pages, page tables,TLB. Please make it proper descriptive take your time and make us understand it crystal clear.

[@moyoloco09]

I'm currently taking an OS subject at university, and oh my god, what a perfect timing. Your videos are really helping me to better understand theory around the subject. Nice video, I'll be waiting for next!

[@shyamkawadkar693]

your work is truly amazing but if possible share some of the resources is description section so that viewer who is interested could understand it more clearly. thank you for amazing content

[@MrSomethingdark]

Best video on modern digital computing on the whole wide web. Thanks a lot Core Dumped.

[@nesa6582]

And whats crazy, it is free.

[@martingeorgiev999]

14:10 I am not sure about the memory limits part. Each process works in a virtual address space so when it wants to fetch anything from it the MMU just translates it to the physical address or produces an exception/interrupt if there is no current mapping for the accessed address (or if the process does not have permissions to access the mapping). Now, to access the memory of another process as in the example, the OS should have mapped that memory previously and this can be achieved solely through system calls. If the OS works correctly it should never allow a process to map any resource that's beyond the process' privileges. Another note, the 1:07 image is a bit incomplete, usually half of the virtual address space of a process is kernel space where kernel code is mapped (obviously when the process is running in user mode it can't access the kernel mappings).

[@CoreDumpped]

Yeah, explaining this would have make the video 30 minutes longer. So I tend to oversimplify some concepts.

[@handlewithoutsuitcase]

Thanks to all the team working on this! Well done!

[@araara967]

my god this has got to be the most comprehensive explanation of processes I've ever seen. kudos to you buddy!

[@ВладФоменко-р4е]

The explanation is... brilliant!) Ever wondered what those registers are, now I understand that this is just a cpu space to load data from memory for execution. Thank you so much!

[@ivankudinov4153]

amazing work: thorough accessible explanations of truly important stuff and curated set of continuous themes. I hope you'd continue this channel in the same fashion. Have to mention the editing it's superb

[@aitanapalomanespardos7089]

Wonderful video! The part where you show files as something that is not part of the program but the process has helped me better understand the question I asked you in the previous video (I had thought the file was part of the data section, so I had thought that if the data section was different, they were different programs). Thank you for making these videos, you tackle most of the questions the viewer might get visually and in detail. Looking forward to more videos from you!

[@abhinavachha7922]

Thanks!

[@artyomtimiriazev2070]

I love your videos. I've finished university a few years ago and some concepts started to fade away from my mind but your videos are not only a perfect refresher but also add some new and interesting information. And so well produced. I do hope you keep getting more and more sponsorships

[@SayedAli-gq8bl]

Hey George. Your videos are incredibly satisfying to watch. They let me follow your train of thought both visually and by listening to your well-articulated words. I get multiple "aha" moments in each video. I'm sure tons of work goes into creating each one, so I hope you can keep it up.

[@tech_simpleterms]

The way the explanation is taking place from the beginning to end really marvelous. Eagerly waiting for the next episode.

[@Merilix2]

I remember, in the late 80's there was a Modula2 compiler for MSDOS including the source code for the PROCESS module and the source for an timer interrupt handler (written in M2) acting as scheduler for the process queue. That was quite useful to understand how multitasking works under the hood and what issues need to be solved when synchronization between processes becomes important . Unfortunately I don't remember what exact M2 version that was.

[@adamboyd348]

This is unbelievably good!! This is exactly what I want to learn as a junior software engineer who lacks a computer science degree. Said by a few others in the comments, there is a big interest in this content. Thank you.

[@barryallen5243]

Thanks for the brilliant video once again. On another note, what does ARC represent here. ARC vec

[@CoreDumpped]

Arc stands for Atomic Reference Count

[@aenguswright7336]

Arc is required to safely share data between threads in rust as it keeps a record of how many processes rely on it.

[@priyank_panchal]

I'm totally addicted to your videos. I'm always eagerly anticipating the next one. Your content on OS fundamentals is fantastic. Keep up the great work.🎉

[@tratmir]

Literally love this channel! Personally I can't imagine the amount of work that goes into animating and editing all of this. Please keep it up!

[@DemonAspicious]

I don't usually coment on any video, but this channel has something different. You explain these low level concepts in a way no one else does. The clarity of the explanations is astonishing. Keep going, you're doing a great job! I can't wait to see your next videos!

[@by010]

As per usual, great video.Please keep it up. One thing Im left wondering about is how the context copy scheme works. That procedure must use some logic, and things like registers need to be preserved without modification, right? Is there some kind of hardware acceleration or assistance for this in modern CPUs, or is it handled in another way? I’d love to hear more details on that. One of the things I love about your channel is how you build out every topic so exhaustively, leaving almost no room for questions. I think it's first real one I have. What you’re creating is seriously exceptional quality. Thanks for the upload!

[@CoreDumpped]

Two examples: -Use of Registers Sets: The operating system uses its own set of registers so while performing the Context-Switch it doesn't overwrite the state of the interrupted process. -Every time an interruption is fired, the CPU automatically copies the content of ALL the registers to a hardcoded memory location. So, yeah, hardware support is needed. Again, these are just two examples; there are more ways to handle the problem you described. Ultimately, whatever method is used depends on the CPU architecture.

[@by010]

@@CoreDumpped Okay, that makes sense. Thank you!

[@jeffersonwu952]

I have watched every video that you have made here, and I just want you to know they are extremely well done! Thank you so much! You are definitely making an impact to the world of learning :) PS: if videos like these are used in college, professors can probably skip the lecturing part and just do Question and Answer.

[@ryan_chew97]

Bro keep making low level videos these visuals aren’t found any where else. You’re gonna blow up in subs there’s a huge market for this.

[@cofrante6560]

George, your videos are absolutely perfect, easy to follow, well animated. I can't explain how grateful i am with your content. Keep it up!

[@amj864]

By the time you finish this series, these should be taught in unis. Great work.

[@deezydoezeet]

Oh my goodness, I could like the video a thousand times over. The Process Control Block has been the missing piece for me all this while. This is such a great resource

[@balram8223]

i learn from you 100000X more then my university has ever taught me keep up this work and please try to upload more frequently

[@Ajstyle45]

wwoww.....This is arguably the best explanation for such complex concept. hats off!

[@crystal93pl]

They should show this video in IT department classes. The visualizations are incredibly fascinating. I recommend your videos to other developers. I can see that they are starting to understand more.

[@AnantaAkash.Podder]

Following you for almost more than 6 months+... You truly are Criminally Underrated KZbinr... Even after Subscribing I am Not getting your Videos Update... I have to manually Come here to see if any New Video is being Uploaded.

[@NoahSteckley]

Love that the code representations are in Rust. It’s such a clear matter-of-fact expressive language

[@luisalves9738]

Loved the production! What a fantastic channel 👌👌

[@ckpioo]

woah this was extremely easy to follow, and thank you for using rust for the example code, I think rust is the best language to show examples for such concepts

[@hackytech7494]

Thank you so much for this wonderful amazing explanation. Eagerly waiting for CPU scheduling video.

[@reeshabhchoudhary5112]

Core Dumped is one channel which I made sure, I visited regularly while researching and writing my book.

[@reylui0250]

i have an exam this friday about processes, os, threads and cpu scheduling... i need your videos more than water

[@aaliboyev]

Absolutely amazing content, thank you! BTW what animation tools you use for creating animations like this?

[@CoreDumpped]

Everything you see on my videos is PowerPoint slides.

[@charlesbabbage6786]

@@CoreDumpped Respect! 👍

[@Adhithya2003]

@@CoreDumpped WHAT!!? Awesome, I thought you custom made your own animation framework (like manim python). I guess I grossly understimated powerpoint 😅

[@skilz8098]

For those who aren't aware, the Power Point application is Turing Complete. Someone has actually made a basic general-purpose CPU with its slides and transitions states. Power Point is very flexible and powerful!

[@trantuan6828]

This is the most amazing video I have ever seen! I will always support you in your future content creation on KZbin. Thanks a lot Core Dumped

[@mmmm123456780]

Great video! It just misses one thing. I think you should mention that the OS itself also is something that is executed by the CPU, so simply claiming that it manages a context switch doesn't really explain how it works. Therefore I hope that you plan some video about interrupts.

[@tornado3007]

i always love your videos the animations are very well done and you explain it in detail without overwhelming. please keep this series going i already learned a lot < 3

[@glaisonpassos3775]

Jorge, seus vídeos são excelentes! Muito obrigado pelo trabalho formidável.

[@roadrunner3563]

Terminology varies over time and by operating system. At least one older OS refers to an executing program unit as a process (program vs process virtually synonymous). It didn't specifically have "threads" but could perform some types of asynchronous operations within a program/process and "enter-process" (enter-program) communication was via shared memory DMA (usually extremely fast ECL) or other bus interfaces.

[@ManojKrVerma-vw4dx]

What app do you use to make these animations ?

[@Colaholiker]

I was curious about the same

[@SetKat-Alex]

From another comment, it's PowerPoint!

[@Colaholiker]

@@SetKat-Alex 🤯! That is amazing. I personally find it (and the entire Microsoft Office product family for that matter) so not user friendly,thst I prefer Libre Office I didn't even know that this is possible in what I always call "the game managers can play at work".

[@thefanboy3285]

@@Colaholiker The MSOffice suite is HELLA powerful ! Unfortunately, it came from a time when UI/UX designers didn't exist yet and because of legacy teachings, the layout can't really adapt to modern principles. So it got just more and more powerful and also more messy. But I can guarantee you, these things are fking powerful. Someone even used Excel as a game engine because it can simulate (albeit a bit slow) 3d renders and 2d renders also.

[@Colaholiker]

@@thefanboy3285 I have to disagree when it comes to UI design. My last MSOffice that I used personally was Office 97. Great UI. Menus well thought out and it made sense. Than some drunk lobster at Microsoft invented the "ribbons" and things went downhill from there. These things rearrange all the time, you don't find what you are looking for, they are terrible for keyboard-focused users... I don't doubt that the programs are powerful. But they are just terrible to use. And the Windows 10 theme that flattened all control elements, where you can't tell a button from a label, especially in dark mode, made it even worse...

[@davevann9795]

Each component of a computer is functionally very simple. They only appear complex because humans try to do complex things with these simple functional units, and therefore have to combine many layers of many simple functional units, interacting in many ways.

[@oglothenerd]

Lookin' forward to the one about the MMU.

[@charlesbabbage6786]

Absolutely in love with these videos!! Very clear explanations. Keep em coming! 👏👏

[@Gigasharik5]

Bro your channel is hidden gem

[@randomsearches369]

I have never been hooked on such a complex topic

[@FossWolf]

This is some really awesome work buddy ❤ Keep up the good work 🙌

[@mikeowino8732]

I did OS during covid, and I passed even without knowing what a process is. Just crammed for the whole exam. Great visuals, now I am understanding

[@JaredFarrer]

Great channel find! Great job dude.

[@sacate5413]

Hey core dumped, i really enjoy your series of providing better understanding of low-level concept. I also like the animation style, may i ask what software you use to do these animations?

[@ncsham9103]

I don’t know how to commend you man, the videos are just damn good and crystal clear. Thanks so much for demystifying!

[@chainleang5313]

wonderful works,thanks for sharing

[@Andrew90046zero]

I was hoping the video would've gotten into how many instructions done computed before a process is switched, or just how the scheduling is done. But I can't wait to watch the next video that goes into that.

[@justcurious1940]

The Operating system can't do this without hardware support, for switching between processes the CPU has a feature called timer interrupt, and to protect processes from each other there is a special hardware called MMU(Memory manager unit).

[@jeremymcadams7743]

Where is the cpu state being stored? Is the capturing of the cpu state something that is stored in heap memory? Or some special memory location? Edit: I should have waited longer before asking the question

[@CoreDumpped]

I guess the real question is: where is that structure (PCB) stored? Does the OS have a stack and a heap? Interesting topic for a future episode😉

[@jeremymcadams7743]

@CoreDumpped That is an interesting question. The stack is normally restricted in size by the OS, but the OS makes the rules, so I guess it could hypothetically run solely on a very large stack, but it would seem useful to save user process cpu snapshots on the heap external to the stack since you have a dynamic number of processes being generated and terminated.

[@xOWSLA]

@@CoreDumppedcannot wait to watch!

[@ltecheroffical]

@@CoreDumpped I noticed you have a double p in your handle. But it's most likely too late to change it.

[@SweepAndZone]

​@@ltecherofficalyou think he doesn't know that brother 😂😂❤❤

[@Dr10na1995]

Your videos are amazing! So clear and interesting!

[@imadhamaidi]

Your channel is a hidden treasure! Keep up the good work! I wonder if you are interested in covering virtualization topics in the future like Popek and Goldberg requirements.

[@lkiller4788]

Great video as always! I want you to explain how the snapshot of the CPU gets done in low level in a future episode

[@kraller7]

amazing man as always this content is pure pure gold

[@Griffin12536]

I’d love to know how hyper threading deals with all this. I read that it “exposes” 2 contexts to the core but my understanding just can’t fit the puzzle piece. Shoving another dependency chain into the execution unit is straight forward, but what about the non-general purpose registers? Does each core have 2 PCs and SPs and etc.? Can you context switch one without the other or are they switched out together?

[@olhoTron]

For the operating system they are just 2 independent CPUs with their own set of independent registers what really happens inside the physical core.... who knows?

[@skilz8098]

The overview of a process being context switch is very good and all and the mentioning of the scheduler is nice, however, I noticed that there was no mention of or lack thereof of what is typically called an Activation Record(s) within computer science either it being software or hardware engineering. I think this ought to be mentioned and well explained as well as I feel or believe that it is related, relevant within the context of this topic or material. Other than that, excellent video, great material.

[@ArthurSchoppenweghauer]

This was AI generated so don't expect correct answers.

[@skilz8098]

@@ArthurSchoppenweghauer Possibly.

[@CoreDumpped]

Activation Records are stored in the Stack, and the Stack was in deed mentioned. I even specified that, during execution, programs need memory space to save temporary results. A lot information omitted, I know. But it's very difficult to put so much information into a 15 minute video.

[@skilz8098]

@@CoreDumpped True. So perhaps it was in an older video leading into this one. It's just that the association of it within the context of process space was kind of left out.

[@MathCuriousity]

Please do a video on “NON-WEB API’s”. I would love to learn about API’s (the non web ones) as well as kernel level and user level! Please do an incredible 30 min video on this!!!!❤❤❤❤❤

[@SirusStarTV]

@nirlichtman have some good stuff about win api

[@MathCuriousity]

@@SirusStarTV where? Can you add link?

[@DracoIgnem]

Another Great Video with Great Animation. Thank You for your work !!

[@prajwals8203]

Thanks for vid.....I think some part of what you cover is from "Operating System Concepts" book And luckily that's our textbook ....so this helps in exam prep

[@siwoopark2898]

Sir, you will be recognized someday, at least 1M sub. Please keep up these great work!

[@viktornikolov1570]

Your videos are gold. Are there any resources you can share for further reading?

[@a.v7998]

Amazing video! Learning these low-level concepts is so fascinating!

[@Shahikulariyan]

you are a awesome teacher in my life i have ever seen 🥰🥰🥰

[@badtrevor773]

I watched your video about how transistors remember data, and I found it brilliant, your explanation was excellent. I would like to make a request: if possible, please dub your videos with AI (or however you prefer) to reach more people. I watched your video using an Opera extension to read the automatically generated subtitles. I am Brazilian and only speak Portuguese, my native language. I believe it would be very beneficial for you and for those who enjoy this kind of content if it were more widely shared. Your videos deserve to spread worldwide and reach as many people as possible. If you can't or don't want to do it yourself, I would like to ask for your permission to dub your videos with AI and post them (I won't monetize the content, nor do I have a subscription, I'll just make a "gambiarra" haha) giving you full credit. That's all. I loved your video and wish you all the best and much success. Congratulations on the excellent work and the care you put into your content.

[@code-monet9468]

The references to ThePrimeagen are genius

[@sharathkumar8338]

Please make a video on threads next.

[@FLAMESpl]

Isn't accessing memory every context switch extremely slow? Is there a solution in cpu hardware to keep separate cache for contexts that won't be replaced by user space memory when process accesses various regions of it?

[@furkanvural4384]

Your explanation is insane .keep going

[@GeoffryGifari]

Are there special addresses in the memory for storing the "snapshots" of the CPU state? Can these be overwritten by something else?

[@GeoffryGifari]

Oh and is there a limit to how many CPU state snapshots (corresponding to the number of processes) can be stored at a given moment?

[@SirusStarTV]

OS kernel code have entire RAM into its possession, it can store whatever data wherever it wants (not touching processes address spaces).

[@CocolinoFan]

Do you have a video explaining how Segmentation Fault (Core Dumped) happens?

[@CocolinoFan]

13:50 Ah, I see. Very cool.

[@MasterGxt]

Love how Core Dumped uses Rust for psuedo code

[@abdeljalilelmajjodi4954]

Ammazziiiing , Thank you very much

[@Holsp]

Where is that snapshot stored? In the cache?

[@milosmandic6129]

Great video man. Where is the PCB stored? Is it in the heap of the process or is ist stored in the OS memory?

[@adityav7020]

Thank you for this video CoreDumped

[@vitobrusnik6953]

High quality content. Well done.

[@spaghettiking653]

Thanks, I just have one question: when the OS starts executing some other program, how does it ever get back out? E.g., if the OS hops into a part of an entirely separate process, and changes the program counter to point to that program instead, how does it regain control and switch back to its own execution?

[@CoreDumpped]

I explained this on my video about concurrency. There are two ways: -System calls: The process itself calls the OS when requesting some resource. -Timer interruptions: Right before allocating the CPU to the "next" process, the OS uses an special instructions to set a hardware timer. The process might still return control to the OS via a system call, but if it doesn't, once the timer expires it will trigger an hardware interruption that makes the CPU jump to the OS executable code.

[@ShinSpiegel]

Amazing video, super educational. Thanks for sharing.

[@coding_diari]

Can you share the link to the Linux kernel repo?

[@letsgetrusty]

Peak CS content 🔥

[@whtiequillBj]

do you have a video explaining IPC (inter-process communication) in the queue?

[@CoreDumpped]

I do

[@thisisnotok2100]

Can you do a video about how in process threads split their scheduling? Such as tokio for rust

[@CoreDumpped]

Async runtimes like tokio, require implementing a very complex task scheduler, pretty similar to an OS-level CPU scheduler. So I guess my video about CPU-scheduling will answer a lot of questions. I've also been thinking on recording a video exclusively about how async-rust works, but is not a priority.

[@filipniklas]

Great video! But doesn't the OS itself also need to be run on the CPU? The context switching must require processing as well, right? How would the whole thing be juggled then?

[@CoreDumpped]

I was waiting for this question😄 I'll cover this soon in an episode. But the short answer is: Hardware support. Operating systems have access to Privilege Instructions that User Programs don't. The problem can be addressed by: Using multiple sets of registers, so when the OS is invoke it uses its own register set to operate, hence not altering the state of the interrupted process. Another way can be a Privilege Instruction that copies (in one go) the content of ALL the registers into a specific memory location whenever an interruption is fired. These are only two examples, I'm pretty sure there are more ways to do it.

[@filipniklas]

​@@CoreDumppedappreciate the reply! Yes, this makes sense. I look forward to the episode on this 😃

[@kaviarasan8249]

Thanks ❤ this is pure gold

[@sshrek1996]

Hello! This is absolutely amazing work. Computer Architecture fundamentals in its easiest form. Can you please suggest any books on microprocessors and computer architecture?