- cmsg cancel <nfo7ho$k0e$2@dont-email.me> - 3 Updates
- Read about logic and USL... - 1 Update
- Important: I have finally understood ... - 1 Update
- What is this nonsense ? - 1 Update
| bleachbot <bleachbot@httrack.com>: Apr 26 07:15PM +0200 |
| bleachbot <bleachbot@httrack.com>: Apr 26 08:04PM +0200 |
| bleachbot <bleachbot@httrack.com>: Apr 26 09:14PM +0200 |
| Ramine <ramine@1.1>: Apr 26 03:16PM -0700 Hello.... Please download here the free book about USL methodology from Baron Schwartz: https://www.vividcortex.com/resources/universal-scalability-law/ You can read clearly inside the book this: -- "To forecast scalability beyond what's observable, be pessimistic and treat the USL as a best-case scenario that won't really happen. Use Equation 4 to forecast the maximum possible throughput, but don't forecast too far out. Use Equation 6 to forecast response time." -- As you have noticed he is not saying "don't forecast", he is saying clearly: "don't forecast too far out", that means that you can forecast not too far out. And that's illogical, simply because, in a parallel program, a locked region using locks can escape contention at fewer cores and fewer threads and can than hit the contention at more cores and more threads.. so you can not use nonlinear regression to predict scalability, so why Baron Schwartz is saying: "don't forecast too far out", so i mean why then forecast, since you can not predict scalability ? that's like illogical from Baron Schwartz ! so what is the purpose of the USL methodology that uses nonlinear regression? its purpose is to permit us to test and see how much there is contention and how much there is crosstalk(cache misses etc..), that's all, it's not a tool to predict scalability. Thank you, Amine Moulay Ramdane. |
| Ramine <ramine@1.1>: Apr 26 02:05PM -0700 Hello, I have finally understood ... I will make you understand the USL methodology... If you read this book about USL methodology from Baron Schwartz: https://www.vividcortex.com/resources/universal-scalability-law/ This Baron Schwartz is saying in this book that USL methodology using nonlinear regression can predict scalability, but i have finally understood that this Baron Schwartz is making a mistake, this is what have made me make a mistake, simply because, in a parallel program, a locked region using locks can escape contention at fewer cores and fewer threads and can than hit the contention at more cores and more threads.. so you can not use nonlinear regression to predict scalability as is saying Baron Schwartz in his book.. so what is the purpose of the USL methodology that uses nonlinear regression? its purpose is to permit us to test and see how much there is contention and how much there is crosstalk(cache misses etc..), that's all, it's not a tool to predict scalability. Thank you, Amine Moulay Ramdane. |
| Ramine <ramine@1.1>: Apr 26 01:21PM -0700 Hello, I have come to an important subject.. Please look at the USL methodology here: http://www.perfdynamics.com/Manifesto/USLscalability.html Dr. Gunther the author of the USL methodology is using nonlinear regression on the performance data measurements to predict scalability? But i don't understand this nonsense ! Simply because, in a parallel program, a locked region using locks can escape contention at fewer cores and fewer threads and can than hit the contention at more cores and more threads.. so how can you than use nonlinear regression to predict scalability ? this is complete nonsense ! Can you please explain to me why Dr. Gunther the author of USL is using nonlinear regression to predict scalability ? Thank you, Amine Moulay Ramdane. |
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