Skip to main content

Parascope

http://www.computer.org/parascope/#journal

A god-sent resource for the likes of me, who do research on Parallel Computing and HPC.

I definitely need to read on most of the journals listed here, because the paper is due the end of this month. Which reminds me, I have yet to find an explanation to the anomalous behaviour from 1K210K (I have just coined it such, because of anomalous behaviour from the tests from chunk size 1K to 10 K). Possible explanations should crop up from hardware performce analysis using microbenchmarks, but that's the last resort. I should be able to find similar tests and results from other studies, right?

I'm starting to believe that I might be the only one with such a setup, and with a test problem like what I have. Well, technically it's not really a parallel algorithm, but the idea of load delegation ala-scheduling is something that people have already definitely studied. However, I have not found any resources showing that what I'm trying to do has been done before, and that there are significant or conclusive results that will back up their claims.

But as for now, I'm still thinking that the performance degradation/irregulity from 1k210k must be realted to some hardware properties associated with the message sizes. After all, I have implemented the solution to the parallel prime number funding problem using MPI and an Ethernet interconnection network (with hub with one setup and a switch with one setup). The degradation/irregularity could also be brought about not only by hardware features and capabilities, but by the actual scheduling algorithm being employed.

I have only been using blocking IO for the message passing from the slaves to the master. One issue could be the waiting time brought about by the first-come-first-served (FCFS) scheduling of the master when it comes to getting results and distributing work. I have yet to confirm this, but on-paper analysis could be sufficient to explain some of the irregularities and performance degradation.

Another issue that can be of value would be the memory access and paging method employed by the Linux kernel. I am not yet familiar with the internals, but I intend to look into them as I try to see whether the kernel has something to do with issues when ti comes to handling the memory allocation (malloc, and free) of irregular block sizes (those not a power of 2). OR, it might still be the actualy hardware details that lie beneath the OS, which I might still have to investigate.

So far, these are just still ideas which I may look into and elaborate on as I go along with my reading. I hope someone else has gone ito these details, so that I would spare myself of having to do research into things I shouldn't be worrying myself about in this stage of my thesis.

Or, I could go till summer or the next semester to finish my thesis. But I wouldn't want that, would I? It's bad enough that the exeriment I'm doing is hard, let alone the analysis and actual research involved with the writeup. Now I appreciate why theses are usually done in at least pairs. It gets really lonely as time goes on...

Chilled.

Comments

Popular posts from this blog

Futures and Options III: Economics, Journalism, or Computer Science

I realise it's been a year since my previous post on this blog, and I've found myself having very little time to do another "brain dump" on the subject of my early choices in life. With that in mind (and as I'll be traveling again soon) I get to think a little more and reflect on a few of the things that have happened.

Much like the previous post, this one's set in high school -- where I was part of the swimming team, in a band, had been programming with Turbo Pascal, Java, and then C++ later on, and was about to make a choice that would literally change the course of my life. This one is about the choices I made, and the ones that were made for me.

Note: This is part 3 of a series about my early choices in life which have gotten me to where I am today. I would greatly appreciate your feedback and thoughts, as well as for your reading through this series!


Rant: Despair and Hopelessness

This weekend I had the chance to do a Google+ hangout with my father in the Philippines. He and I don't talk often but we do have a very good relationship. My dad is cool like that. In this hangout we talked about a few things happening in the Philippines and I've gotten the feeling that my homeland is getting ever deeper into economic disrepair, and that the politics to which I've come to be hopeless on is beyond repair. I've wanted to get something off my chest that's been bothering me for a while now, so if you would indulge me please read on.

Background

I grew up in a part of the Philippines where the land is fertile, there are thriving industries, and there's a certain sense of abundance and stability. This part of the Philippines has good schools, good employment opportunities (mostly industrial and service industries), good investment opportunities (real-estate and agricultural), and good potential for growth. This was true when I was young and this is tr…

Get a Life Coach

Have you ever played a sport whether individual or team sports where your top performance was required for any measure of success? If you have, you may have had the benefit of at least one coach guiding you to point out better form, better strategies, alternative approaches, keeping you accountable, identifying our strengths and weaknesses, and overall telling you to listen to your body and focus on your goals. If you haven't then would you like to have someone on your side, not judging you then generally cheering you on while you attempt to achieve whatever your goals are? For the past year I've been working with a life coach and I can say it's worked so well for me that I cannot help but recommend everyone consider investing in life coaching.

I used to swim back when I was a student in university as part of the varsity team. I had a number of coaches then who taught me not just the technical aspects of swimming, but also the mental fortitude required to train effectively…