Sometimes lecturers went too deep into one topic and failed to realize the majority of students don't even understand the basics, experience gap in my opinion.
we need an education revolution, i see comments like this on every educational video homeschooling / private tuition / autodidactism is the way forward
I was so confused on virtual memory. So many videos from non english speakers which were very unclear to me. Finding your video playlist was a blessing. Crystal clear explanations that cover every detail I had a question about. Thank you very much.
+Brian Olsen Glad you liked it! (Too bad I don't have the in-class demo recorded as it's a lot of fun to see PowerPoint loading fonts and how their sharing state changes.) -David
Thank you so much for making this tutorial. An Operating Systems Class I'm taking really lays the complexity all at once, with this I can transition knowing the idea of VM and what problems it solves, to understanding its implementations.
Very good, I have worked with Cortex M series CPUs, when moving to A series CPU I wanted to know about virtual memory and this gave me nice introduction! Thank you
Simple with context of real world examples ♥️♥️♥️ Your way of teaching is so good!!! This video was way better than all those forums and posts I went through.
Simply freakin awesomeeeeeee!!!! man I 've never seen someone using Powerpoint slides more effective than yours. The profs at college do shitty slides and u r just great.
this dude is underrated i've seen so many other channels explaining the same stuff but not close to this mans level. subbed. hope to see more from you in the future really appreciated the lectures. thank you!
Thanks for making these videos, they are really simple to understand! I found a typo at 6:44 when you write 2. Program 2 stores your video game score at address 1204, it should say 1024
@@Ruturaj22 ??? He's just offering a correction. If you get offended/insecure every time someone corrects something that's not even about you, I don't get how you survived till now.
00:22 Position-dependent code and memory fragmentation enter the chat ;> 02:12 That's a huge oversimplification. Disks cannot be directly addressed like memory. More correct would be to say that we SWAP some memory page to hard disk to free up some space in physical memory, then we can use that memory for our next mapping. 05:58 This doesn't solve the problem though, it only shifts them one level deeper. Because you still can have fragmentation in your virtual address space and virtual memory won't help you with that :q
Hey! Amazing video, you absolutely deserve more recognition and praise for the efforts you put in making such complex topics look so much easier. I just have one small question. When we're talking about #3 keeping programs secure, whats the guarantee that the mapping doesnt write to the same location in the RAM? Had this doubt cz if programs can access same memory location without mapping, is there some condition in the mapping that solves this problem? I wasnt finding very convincing answers on the internet so I thought Ill ask! Once again, great video!
You have a misconception about virtual memory, Virtual memory combines active Ram and inactive memory on disk to form a large range of contiguous addresses. There is also a memory map that comes along with the virtual memory, so the virtual memory and the memory map is a completely different things.
Questions about page out at 4:08: I guess in that example, we can page out program 0 cuz we assume it's no longer needed. But what if we need to process program 0 + 1 + 2 + 3 all at once (like if these 4 programs need to interact with each other and thus need to be in memory together for us to process them)? Q1: In that case, if we cannot page out anything, and we no longer have space for program 3, what would happen? Q2: In real life, what are the solutions to avoid this situation? Thanks very much :)
The mapping of addresses from the secondary storage to RAM is actually done by the Memory Management Unit(MMU) and NOT the virtual memory. Virtual memory is the 'deceitful' picture the kernel gives the program that ALL the RAM size belongs to it and it ALONE.
My god trying to make sense of this from the Tanenbaum book is honestly mental. Why would you explain this concept using 1 illustration and 9 paragraphs???!!!! lol I'm glad other people feel the same.
@David Black-Schaffer *I don't want any paging on my hard drive, I want to export it to an external drive connected via USB, but when I go to my paging options only C: is listed, (not even D) I have a thumbdrive plugged in too, but that doesn't who either. How do I get my OS to recognize a new drive? And how much can I use for paging? p.s. if you're feeling generous, can you tell me, how I might be able to "dedicate" cores in my CPU so that they don't get shared by other programs?*
The first time I heard Virtual Memory, all the concept came intuitively in my mind, but then I watched a crappy tutorial which by someone unable to speak proper english and vomiting their mugged up statements with unnecessary complexity. Now watching this is a so reassuring of the simple intuition that one may get hearing the term "virtual memory" or "logial address space" ... it can be infinite. One thing we must add is that the RAM is hellish faster and while processes are being run, the old pages get removed so quickly that there are always new empty holes... it barely needs to access Secondary memory unless we are running 5 applications all at the same time. Still, there is external USB drive that used to help in the past. Now we have 64 bit address space and 32GB DDR RAMs in laptops.
After almost 10 years, I still find this is the best one on explaining how Virtual Memory works.
Another youtube hero deserving some honourable mention on my degree! Thanks for explaining what my lecturers failed to explain.
great idea, you can put the link here for the paper if it is publicly accessbile, that would mean a lot to him i think!
Sometimes lecturers went too deep into one topic and failed to realize the majority of students don't even understand the basics, experience gap in my opinion.
Man this is amazing, the crappy slides my profs use are horrible compared to this. I also like the use of real world examples.
LOL
At least they use slides, mine use crappy white board and marker with poor drawing skills
Brother, where is stack in this scenario? I couldn't find it 🤔
we need an education revolution, i see comments like this on every educational video
homeschooling / private tuition / autodidactism is the way forward
lol my professor's audio just cuts entirely mid way T-T
This guy is by far the best in explaining this subject
I want my College fees back, you deserve my professor's salary
I was so confused on virtual memory. So many videos from non english speakers which were very unclear to me. Finding your video playlist was a blessing. Crystal clear explanations that cover every detail I had a question about. Thank you very much.
Best tutorial! I was struggling so much to understand Virtual Memory and you made it so much easier! Thaanks!
I'll never understand how youtube videos explain things better than my college class that I pay money for.
This guy is a professor in sweden, he uses the videos in his course
There are many professors, there are fewer EDUCATORS. The serious educators have RUclips videos as they love EDUCATING.
Best explanation I have found on RUclips
Wow, hats off to you David for the concrete save dialog example!
+Brian Olsen Glad you liked it! (Too bad I don't have the in-class demo recorded as it's a lot of fun to see PowerPoint loading fonts and how their sharing state changes.)
-David
What an incredibly clear way of explaining a very confusing topic. Thank you!
Thanks to you, now I finally understand, I spent almost day to understand the realm of this topic.
virtual memory savior is here. Thank you prof
I cant have words for these tutorials u r like an angel..... keep up the excellent work :)
Best tutorial about VM on the internet
Why do I even pay for a college degree? This was so much better of an explanation than why my professors provide me.
short series of watchable videos that contains actual information. pog
oh, man. this is the BEST explanation I've ever got for this subject!!! is not that complicated, you make it so much easier. Thank you.
Thank you so much for making this tutorial. An Operating Systems Class I'm taking really lays the complexity all at once, with this I can transition knowing the idea of VM and what problems it solves, to understanding its implementations.
The best way virtual memory can be explained !!!! Thanks Really learned a lot
this is much better than the incomprehensible ppt slides my prof uses
I love how you explain a complex concept.
Hands down one of the best explanations I've ever seen, I was struggling to find access to this topic but you made it so easy, thank you!
This is the best explanation series on this topic I've seen so far on youtube! So glad I found this
Very good, I have worked with Cortex M series CPUs, when moving to A series CPU I wanted to know about virtual memory and this gave me nice introduction! Thank you
The mapping is done by MMU(Memory Management Unit).
lol
Simple with context of real world examples ♥️♥️♥️
Your way of teaching is so good!!!
This video was way better than all those forums and posts I went through.
This is the best explanation on VM. Thanks a lot for the video.
1000000000000000000000000 times better than my lecturer's explanation!!
Simply freakin awesomeeeeeee!!!! man I 've never seen someone using Powerpoint slides more effective than yours. The profs at college do shitty slides and u r just great.
this dude is underrated i've seen so many other channels explaining the same stuff but not close to this mans level. subbed. hope to see more from you in the future really appreciated the lectures. thank you!
Best Lectures on VM! ❤
this is WAYYYYYYYYYYYYYYYYYYYYYYYY more useful than my teacher's slides
The BEST Tutorial with Nice Graphics!!
Thanks for making these videos, they are really simple to understand!
I found a typo at 6:44 when you write 2. Program 2 stores your video game score at address 1204, it should say 1024
@@Ruturaj22 ??? He's just offering a correction. If you get offended/insecure every time someone corrects something that's not even about you, I don't get how you survived till now.
Thank you very much for this tutorial. You help me a lot of. In 2 days i have an exam and i didn't understand MV. Regards from Spain :D
00:22 Position-dependent code and memory fragmentation enter the chat ;>
02:12 That's a huge oversimplification. Disks cannot be directly addressed like memory. More correct would be to say that we SWAP some memory page to hard disk to free up some space in physical memory, then we can use that memory for our next mapping.
05:58 This doesn't solve the problem though, it only shifts them one level deeper. Because you still can have fragmentation in your virtual address space and virtual memory won't help you with that :q
Хорошо что есть Русский перевод!!!!! Очень понятно!!!
you have helped me pass the exam! thank you
easy for beginner to understand, really appreciate it
thanks a lot. ur videos saved my exam
Salute you man, what a simple and easy to understand explaination
Really excellent video with excellent narration!
Hey! Amazing video, you absolutely deserve more recognition and praise for the efforts you put in making such complex topics look so much easier.
I just have one small question. When we're talking about #3 keeping programs secure, whats the guarantee that the mapping doesnt write to the same location in the RAM? Had this doubt cz if programs can access same memory location without mapping, is there some condition in the mapping that solves this problem? I wasnt finding very convincing answers on the internet so I thought Ill ask! Once again, great video!
Thanks David, very nice explanation of Virtual memory!!!
Props to you, +David Black-Schaffer. Super accessible.
Man i was struggling so much to understand it but you made it easier thanks !
Amazing. Thank you . Most helpful and clear explanation
Nice explanation with pictures and easy for me to understand...thank u
amar putsala, please feel free to take a look at the whole course if you're interested at test.scalable-learning.com, enrollment key YRLRX-25436
well done. Thanks for sharing your knowledge and realization of virtual memory
thanks sir, this help me to prepare my final exam
I salute u .Finally understood the concept
You have a misconception about virtual memory, Virtual memory combines active Ram and inactive memory on disk to form a large range of contiguous addresses. There is also a memory map that comes along with the virtual memory, so the virtual memory and the memory map is a completely different things.
Amazing video. Helped me understand my assignment greatly!
great explanation, very impressive
This is so amazing! Please keep making more videos! Thank you !
best explanation ever bro... you rock...!!!!!!!!
Great content with proper expressions, thanks!
Thank you for this set of excellent lectures!
Thanks! It's really helpful. Your explanation and ppt is easy to understand.
best videos on youtube
Probably the best course on virtual memory. Thabk you. Could you please prepare for the Paging Mechanism as well?
youre explanation is awesome af.
Nice! Really appreciate it, love the visuals, can tell you spent a lot of time preparing. Thank you!
Questions about page out at 4:08: I guess in that example, we can page out program 0 cuz we assume it's no longer needed. But what if we need to process program 0 + 1 + 2 + 3 all at once (like if these 4 programs need to interact with each other and thus need to be in memory together for us to process them)? Q1: In that case, if we cannot page out anything, and we no longer have space for program 3, what would happen? Q2: In real life, what are the solutions to avoid this situation? Thanks very much :)
Clear as day, thanks a bunch!
such lucid explanation, thank you for this.
amazingly explained . Wow
for 6:40. it should be 1024 instead of 1204 for the program 2 address
thanks 4 the real world example sir..
Your explaying it so good and it helped
Definitely deserve a thumb up, but i can't see how many people already thumbed up for ya....
Upto the point Explanation
Hi 👋 so basically virtual address 1.make life for program easier cuz virtual means contagious
2.can add another means of memory like hard disk
Excellent video, really helped me out!
Good Job...David
Keep it up
Thank you! Simply explained!
Clear and concise!!
8 minutes of youtube worth 2 hours of lecture
2022
thanks a lot, the recordings for my OS class with simple slides are really not clear, especially for this type of class, we need something like this.
Reallly very good you save my time thank you
The mapping of addresses from the secondary storage to RAM is actually done by the Memory Management Unit(MMU) and NOT the virtual memory. Virtual memory is the 'deceitful' picture the kernel gives the program that ALL the RAM size belongs to it and it ALONE.
Thank you so so much!! Explained very well to beginners and I love the example.
Good explanation. Thanks!
Fascinating! Solved a lot of my questions...
Excellent explanation
A grand salute to u , amazing explanation
this actually helped so much
Nice tutorial with great slides :)
Explain about the storage management with examples
Big thanks for this..really appreciate your efforts on this
nice presentation
Good explanation
What a hero !
My god trying to make sense of this from the Tanenbaum book is honestly mental. Why would you explain this concept using 1 illustration and 9 paragraphs???!!!! lol I'm glad other people feel the same.
@David Black-Schaffer *I don't want any paging on my hard drive, I want to export it to an external drive connected via USB, but when I go to my paging options only C: is listed, (not even D) I have a thumbdrive plugged in too, but that doesn't who either. How do I get my OS to recognize a new drive? And how much can I use for paging? p.s. if you're feeling generous, can you tell me, how I might be able to "dedicate" cores in my CPU so that they don't get shared by other programs?*
The first time I heard Virtual Memory, all the concept came intuitively in my mind, but then I watched a crappy tutorial which by someone unable to speak proper english and vomiting their mugged up statements with unnecessary complexity. Now watching this is a so reassuring of the simple intuition that one may get hearing the term "virtual memory" or "logial address space" ... it can be infinite. One thing we must add is that the RAM is hellish faster and while processes are being run, the old pages get removed so quickly that there are always new empty holes... it barely needs to access Secondary memory unless we are running 5 applications all at the same time. Still, there is external USB drive that used to help in the past. Now we have 64 bit address space and 32GB DDR RAMs in laptops.
When I think virtual I think of something not Physical. But here it is being saved on another type of storage.
Thanks so much for the time and effort.
Amazingly clear. Thank you so much!
Excellent 👍