multicore

Presumably there is a library or simple asm blob that can get me the number of the current CPU that I am executing on. Use sched_getcpu to determine the CPU on which the calling thread is running. See man getcpu (the system call) and man sched_getcpu (a library wrapper). However, note what it says: The information placed in cpu is only guaranteed to be current at the time of the call: unless the CPU affinity has been fixed using sched_setaffinity(2), the kernel might change the CPU at any time. (Normally this does not happen because the scheduler tries to minimize movements between CPUs to

As a result of my answer to this question , I started reading about the keyword volatile and what the consensus is regarding it. I see there is a lot of information about it, some old which seems wrong now and a lot new which says it has almost no place in multi-threaded programming. Hence, I'd like to clarify a specific usage (couldn't find an exact answer here on SO). I also want to point out I do understand the requirements for writing multi-threaded code in general and why volatile is not solving things. Still, I see code using volatile for thread control in code bases I work in. Further,

The other week, I wrote a little thread class and a one-way message pipe to allow communication between threads (two pipes per thread, obviously, for bidirectional communication). Everything worked fine on my Athlon 64 X2, but I was wondering if I'd run into any problems if both threads were looking at the same variable and the local cached value for this variable on each core was out of sync. I know the volatile keyword will force a variable to refresh from memory, but is there a way on multicore x86 processors to force the caches of all cores to synchronize? Is this something I need to worry

What's the status of multicore programming in Haskell? What projects, tools, and libraries are available now? What experience reports have there been? Don Stewart In the 2009-2012 period, the following things have happened: 2012: From 2012, the parallel Haskell status updates began appearing in the Parallel Haskell Digest . 2011: Parallel and Concurrent Programming in Haskell , a tutorial. version 1.1 released by Simon Marlow Haskell and parallelism , mentioned in an article in the Economist magazine, Jun 2nd 2011. Parallel tree scans via composition , an article by Conal Elliott Numeric

Is it true that the x86 ASM "LOCK" command prefix causes all cores to freeze while the instruction following "LOCK" is being executed? I read this in a blog post and it doesn't make sense. I can't find anything that indicates if this is true or not. It's about locking the memory bus for that address. The Intel 64 and IA-32 Architectures Software Developer's Manual - Volume 3A: System Programming Guide, Part 1 tells us: 7.1.4 Effects of a LOCK Operation on Internal Processor Caches. For the Intel486 and Pentium processors, the LOCK# signal is always asserted on the bus during a LOCK operation,