CPU Scheduling Basics
ฝัง
- เผยแพร่เมื่อ 26 ก.ค. 2024
- Patreon ➤ / jacobsorber
Courses ➤ jacobsorber.thinkific.com
Website ➤ www.jacobsorber.com
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This video is a bit different from my norm. I'm traveling and can't be physically there to teach my Operating Systems class. So, this video is primarily for my class. I hope it's useful to the rest of y'all, too.
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Welcome! I post videos that help you learn to program and become a more confident software developer. I cover beginner-to-advanced systems topics ranging from network programming, threads, processes, operating systems, embedded systems and others. My goal is to help you get under-the-hood and better understand how computers work and how you can use them to become stronger students and more capable professional developers.
About me: I'm a computer scientist, electrical engineer, researcher, and teacher. I specialize in embedded systems, mobile computing, sensor networks, and the Internet of Things. I teach systems and networking courses at Clemson University, where I also lead the PERSIST research lab.
More about me and what I do:
people.cs.clemson.edu/~jsorber/
persist.cs.clemson.edu/ Note that any Amazon links in my video descriptions are generated by Amazon. If you click one of them and then buy something it helps support this channel. Thanks.
***
Welcome! I post videos that help you learn to program and become a more confident software developer. I cover beginner-to-advanced systems topics ranging from network programming, threads, processes, operating systems, embedded systems and others. My goal is to help you get under-the-hood and better understand how computers work and how you can use them to become stronger students and more capable professional developers.
About me: I'm a computer scientist, electrical engineer, researcher, and teacher. I specialize in embedded systems, mobile computing, sensor networks, and the Internet of Things. I teach systems and networking courses at Clemson University, where I also lead the PERSIST research lab.
More about me and what I do:
www.jacobsorber.com
people.cs.clemson.edu/~jsorber/
persist.cs.clemson.edu/
To Support the Channel:
+ like, subscribe, spread the word
+ contribute via Patreon --- [ / jacobsorber ]
+ rep the channel with nerdy merch --- [teespring.com/stores/jacob-so...]
Source code is also available to Patreon supporters. --- [jsorber-youtube-source.heroku...]
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![The moment we stopped understanding AI [AlexNet]](http://i.ytimg.com/vi/UZDiGooFs54/mqdefault.jpg)
16 minutes summed up my whole 2 hour lecture thank you
You're welcome. Glad I could help.
+1
Hah, imagine having a teacher or prof. so cool that they have their own high quality channel, but also says when something might show up on a quiz. Love the videos, you've helped me a lot.
I've been a programming since 1989 or so, always wondered about this but never got around to this. Cool beans.
Very clear and helpful explanation
Great videos! I wish I found you earlier.
Keep up the good work.
Great lecture! Thanks!
Great content! Love your videos!
Thanks, Jonathan. Glad you like them!
Very helpful video! Thank you!
You're welcome.
Lol @ -20 niceness impersonation ;)
well explained👍
Fantastic, thanks a lot.
Love your channel jacob , wish i had found this earlier .
Thanks, Santosh. Glad you're enjoying it.
I've been watching your videos for a little while now (Great Content by the way! Loving the neat tricks you can learn from watching your videos!) But I died when you started quoting the whole B.S. oath - It's been 10 years since I heard all that lmao
Glad you enjoyed that.
absolutely phenomenal video, but I just wanna point out that SJF (shortest job first) is actually different than shortest remaining time first SRTF
Awesome
the scout law reference lol
Best of video is the LEGO in the background ... just kidding. ;o) Good explanation and nice LEGOs.
Pls make playlists for OS and embedded system
What is the difference between chrt and nice utility for process scheduling in linux? Could you please explain sched_setscheduler ( sched.h ) and related system call with an example .
chrt is more general and more powerful than nice. Nice basically changes the inverse of the processes priority assuming the default Linux scheduler. With chrt, you can change the scheduler. Linux offers a few different schedulers (check the chrt man page for details), and the naming is a bit misleading, because they refer to "real-time" scheduling, but Linux isn't a RTOS. So, this isn't real real-time scheduling (no deadlines). It's just a higher priority scheduling algorithm. If you need an RTOS (you're implementing flight control on an airplane or running a self-driving car) I would recommend looking somewhere other than Linux.
@@JacobSorber Thanks Jacob for the explanation. Please continue to make more videos on OS. Do you think is it worth to make a continuation video on process scheduling with More system calls like sched_setscheduler etc .?
On Intel proc allways look to call and jump to be paired with ret on binary Code but, gcc forget sometimes, this îs big problem on linux.
Do these scheduling techniques differ for RTOS?
Yes. In real-time scheduling tasks have deadlines, and the scheduler has to reason about those deadlines.
Some RTOS can have both real time and standard tasks. Also, the Linux kernel can have real time tasks. Real time is a very overused term. Know the requirements of your system and then look for an OS that can handle those requirements.
@@ailijic It's not just the OS; go look for suitable silicon also. Back in the day that might have been Motorola 68k or even MOS 6502. These days it's prolly s/th like ARM Cortex-R.
11:50: "If alpha is one, then we ignore reality and we just go with the last prediction...
If alpha is close to zero, we predict almost solely based on the last experience..."
So either the last or the last? That doesn't seem to make too much sense...?
There's the last prediction (p_n, what we predicted last) and the last experience (m, what actually happened last). They're both "last" things, but different things. Sorry for the confusion.
@@JacobSorber Thanks for taking the time and answering everything. You're really nice, and not in the scheduling sense either. :) I plan to watch all your videos, but there's a whole year's worth still left. :)
14:59 Sounds like Ta'arof in Iran :)
Avg. Response time 7:51 is wrong, should be 4.33.
P1: 0
P2: 7 - 2 = 5
P3: 7 + 4 - 3 = 8
The OS/2 scheduler was so bad. If a task/thread went into an infinite loop, with no system calls, the whole system would hang.
....Wait, was that a Boy Scout joke?
"7,214 views" ? wHaT?
*MY PROF IS HORRIBLE* 🤦♂️
#helpMe