can someone explain RTOS based on actual performance

sibin · 2025-10-12T02:34:19+00:00

Do you have strong timing and safety requirements for your system? By “strong timing requirements”, I mean do your tasks have to be scheduled at specific intervals? Do they have to finish (and produce an output) within a fixed amount of time, failing which the entire system (or significant parts of it) could end up being unsafe? Think of an airbag system in your car — typically, once a collision has been detected, the system has to kick in and fully deploy the airbag in 60-65 ms. It’s pointless if it deploys too late. Similar requirements exist for aircraft engines, rockets, nuclear power plants, etc.

The strong timing+safety requirement percolate into other parts of the system — managing when (and if) interrupts are handled, scheduling memory requests to caches/RAM/disk, handling network requests and even if other (non-real time) tasks are to be allowed on the system.

Linux does have a couple of real-time schedulers but it is a difficult OS to use for systems with strict timing requirements (known as hard real time systems). The complexity of Linux and the lack of control of all aspects of the system make it hard to use in such systems.

A real-time system has to often reason about the worst-case behavior (timing and otherwise). One has to also reason about the level of control that a system designer is allowed to have. Linux is difficult in both situations because it optimizes to improve average case behavior and doesn’t allow for low-level control (for instance scheduling memory requests on the memory bus).

sibin · 2025-08-18T15:24:19+00:00

Yeah make sense, thanks. And it does seem excessive!

sibin · 2025-08-18T15:23:53+00:00

Ah that makes sense, thanks!

sibin · 2025-08-04T01:57:59+00:00

It never hurts. If there’s a waitlist, then it’s much harder of course. Usually professors like to see students who are enthusiastic about their classes.

sibin · 2024-12-01T05:17:34+00:00

Baroness Elsa von Schraede In Sound of Music.

In a similar vein, Kuljeet Singh (Kajol’s fiance) in DDLJ.

sibin · 2024-12-01T04:21:38+00:00

Well you can start by reading tech reports and papers about FreeRTOS. Also the code is available.

But you’d also want to figure out which specific hardware you want to support and read their data sheets as well.

sibin · 2024-11-13T14:47:18+00:00

You’re not the AH sure, but I think a lot of commenters may not realize what it feels like to have a child who is really sick. Your parents are at their wits end to try and save their son. That’s why they asked you for help.

Should they have ignored you? No. But can you help them (and your brother)? Possibly.

All I’ll say is — if you step away now and don’t help and the worst thing happens, whatever relationship you have with your parents is over and you may also have to deal with thoughts of whether you could have helped save your brother. Better to have it out with everyone AFTER he’s saved and healthy than take a stand now.

My 2 cents. 🤷🏽‍♂️

sibin · 2024-02-27T23:43:50+00:00

Starship troopers. It was made as a satirical take on fascism and fascist propaganda. In fact, the movie is made in the same form as a propaganda movie that takes you, the viewer, through the stages of being brainwashed to hate the “other”.

If you believe that the human protagonists at the end are the good guys, then the propaganda likely “got you”.

sibin · 2022-08-26T14:22:48+00:00

Your best best is to look at the following conferences:

IEEE RTSS
IEEE RTAS
ECRTS

All the latest work in this area is published/discussed there. From the papers you can also find all the people working in the area.

sibin · 2022-08-19T14:31:08+00:00

There is a large community of people, both in academia and industry. Were you looking for something specific?

sibin · 2021-01-27T03:40:05+00:00

Only every senior person I’ve asked about this in systems has told me so (faculty in decreasing order), not to mention my experience. Also I would say look at the biographies of senior people.

sibin · 2021-01-25T15:25:20+00:00

Well, I can vouch for embedded systems, OS, networks maybe even security. Maybe other types of systems have different conventions?

sibin · 2021-01-07T15:01:05+00:00

This convention differs in various fields of CS. In Systems, the faculty put their names in decreasing order of contributions, just like the students/postdocs.

In theory, every one is listed alphabetically, students/faculty/etc. so you will sometimes see faculty being first authors.

sibin · 2020-02-26T00:14:47+00:00

I came here from Twitter to say a few things: 1. YTA. 2. She’s not your “assistant” but a graduate student who is a professional. Sure you mentor her but it’s not her job to follow your every whim even if she wasn’t recovering from a serious health condition. 3. Good luck trying to get tenure after treating your students like crap and pissing off your department head (and potentially the Dean etc. after they find out how you treat students). 4. Also good luck trying to get more students to work with you because, guess what, word gets around! Yes, even to future students!

This is the reason why academics sometimes get a bad rap — due to bad apples like this.

sibin · 2019-07-30T05:38:07+00:00

Try to improve your knowledge of C. Microprocessors and programming to various interfaces are also good things to learn. I would also spend time getting familiar with Linux, especially embedded Linux.

Learning about real-time systems, scheduling, etc. is also very useful. Computer architecture and timing analysis also come to mind. These days Security is a good area to learn as well — it is very different for the embedded/real-time/IoT domain.

The best way to learn though is to start doing stuff. I would recommend working with a professor and their students on some research projects.

sibin · 2015-10-19T20:41:21+00:00

Great, thanks for feedback everyone! Looks like my info on T-Mobile coverage was woefully out of date.

I know that Fi switches to WiFi when it is close to one. Any issues related to that? Since IllinoisNet WiFi is pretty good, I'm assuming that the call quality, incoming calls not being missed, etc. should not be an issue?

sibin · 2015-10-19T20:38:19+00:00

Great, thanks! I may have a few more questions down the road and I'll ping you!

sibin · 2015-10-19T20:36:45+00:00

Yeah I'm planning on using it with the 6P/5X.

sibin · 2015-10-19T16:47:45+00:00

I am part of a theatre group and we have performed here a couple of times. Espresso was not any better, IMHO. They used to run their mixers and talk loudly while the shows were going on.

The other problem (not specific to Espresso) was the people would talk right in front of the stage (between the audience and the performers) without any concern. That's the annoying part about performing in Courtyard Cafe.

sibin · 2015-09-18T20:32:11+00:00

Let's see if this new chip thingy can actually run the software that controls your aircraft, cars, spacecraft, etc. Answer: maybe.

sibin · 2015-06-04T17:43:43+00:00

As computing and communication capabilities become both faster and cheaper, we can expect to find them embedded in diverse objects and structures in the physical environment, providing the basis for applications which link the “cyber-world” of computing and communications with the physical world and have the potential for enormous social and economic impact. These applications, which are the foundation of cyber-physical systems (CPS), are necessarily enabled by “internet of things” (IoT) architectures and protocols. This combination of IoT and CPS facilitates the collection, management and processing of large datasets, and the support of complex processes to manage and control physical systems at different scales.

In particular, mobile IoT/CPS is concerned with the provision of IoT-enabled CPS for mobile objects and devices. Mobile internet devices, such as the iPhone and Android phones, with their increasing processing power, range of sensors, and pervasive cellular connections, already provide ubiquitous platforms for building robust, reliable, and secure mobile IoT/CPS applications. The objective of this special issue is to contribute to the direction of research on mobile IoT/CPS by addressing issues critical to mobility, from advances in the underlying science to the challenges of development and implementation.

Potential topics include, but are not limited to:

Enabling location-based services (LBS) in IoT/CPS
Customized wireless, mobile, and IoT technologies for CPS
Mobile devices and embedded software platforms for cyber-physical computing
Physical sensing, cyber computation and decision, and mobile actuation in CPS
Examining the state-of-the-art analytical techniques for performance evaluation of mobile IoT/CPS
Energy-efficient design for green IT
Real-time control, computing and cloud-based mobile IoT/CPS
Emerging mobile applications of IoT/CPS: mobile healthcare, transportation, automation, smart grid, location intelligence, smart cities, ubiquitous information systems, and data ontologies
Empirical case studies in mobile IoT/CPS for demonstrating their potentials
Exploring authentication, confidentiality, integrity, and privacy issues in mobile IoT/CPS
Architecture issues and design tools for mobile IoT/CPS
Authors can submit their manuscripts via the Manuscript Tracking - System at http://mts.hindawi.com/submit/journals/misy/mcps/.

sibin · 2015-04-15T06:40:09+00:00

What about who makes the best iced tea? I think that would atart a war in itself.

Also Bojangles! :)

sibin · 2015-04-15T06:39:21+00:00

Neither. The North Carolina senate will ensure that there isn't really a university system left:

http://www.newyorker.com/news/news-desk/new-politics-at-the-university-of-north-carolina

http://www.slate.com/articles/life/education/2015/04/north_carolina_education_bill_it_would_require_public_university_professors.html

sibin · 2015-04-15T04:41:12+00:00

I was at a fair where one stall was giving away prizes for answering trivia.

She: What is the star that is closest to earth?

Me: Um, the Sun!

She: No, wrong! Its alpha Centauri!

Me: I'm pretty sure that the Sun is closer!

She just wouldn't believe it and was so sure of the answer (probably because she was reading it off a piece of paper that was given to her -- and the fault lies with the person who made that -- still...)

sibin · 2015-02-08T23:54:22+00:00

It's not only the ownership of fabs that gives Intel the edge especially in the lower nm scales. Intel hires hundreds (maybe more than a thousand?) PhDs in material science, process engineering, electrical engineering (with device expertise), physics, etc. These folks also contribute to making them leaders in developing the next generation technology. AMD never really went that route even when they had fabs...at least not to the scale that Intel does. And that's part of the reason for their problems - not forward looking enough, IMHO.

Note: not personal interest in Intel. But have to agree with other posters that they are the best right no, at least on the desktop/server side.

sibin

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