This article describes a parallel merge sort code, and why it is more scalable than parallel quicksort or parallel samplesort. The code relies on the C++11 “move” semantics. It also points out a scalability trap to watch out for with C++. The attached code has implementations in Intel® Threading Building Blocks (Intel® TBB), Intel® Cilk™ Plus, and OpenMP*.
Is cilk_sort functions parallel drop in replacements for the C qsort function?
I read on the doc that array notation can be used for array indicies in both cases :
C[:] = A[B[:]] and A[B[:]] = C[:]
I try to use this notation for left & right operands at the same time but it gives me wrong results.
Here is my problem:
In my search application there are globally variables defined outside any function that I would like to use the cilk reducers on.
Specifically I have code like this:
#include "search.h" static int total_users = 0; static int total_matches = 0;
These total_x variables are incremented throughout the application on different functions.
I tried adding the following for total_users and received the following error:
I have a C search application on a centos 6.x 64 bit linux server that I just installed the cilkplus compiler on to take advantage of more cpu/cores. I've added the cilk_spawn function to some recursive scanning functions in my program. After re-compiling the search application with the cilkplus gcc compiler, the search program is working as intended without any seg faults or any other errors.
My question is how do I use the cilkview analyzer? I want to if cilkplus/spawning is helping my search application and if so by how much?
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Explicit Vector Programming – Best Known Methods
Why do we care about vectorizing applications? The simple answer: Vectorizing improves performance, and achieving high performance can save power. The faster an application can compute CPU-intensive regions, the faster the CPU can be set to a lower power state.
First I would like to thank you all for the awesome cilk plus tools you have open source in GCC and LLVM.
I am trying to study the runtime library and finding it a bit difficult to follow the execution in a sample application.
Are there any developer documents available? A wiki perhaps.
Specifically, I am trying to trace the execution path for cilk_spawn which is a key word. Any helpful links to get me started would be really great!
What I understood about steal-continuation is, that every idle thread does not actually steal work, but the continuation which generates a new working item.
Does that mean, that inter-spawn execution time is crucial? If 2 threads are idle at the same time, from what I understand only one can steal the continuation and create its working unit, the other thread stays idle during that time?!
As a debugging artefact, I had a global counter incremented on every function call of a function used within every working item.