Re: Poor memory allocation performance with a lot of threads on 36 core machine

2016-02-18 Thread Witek via Digitalmars-d
On Thursday, 18 February 2016 at 13:10:28 UTC, Dicebot wrote: On 02/18/2016 02:00 PM, Witek wrote: So, the question is, why is D / DMD allocator so slow under heavy multithreading? The working set is pretty small (few megabytes at most), so I do not think this is an issue with GC scanning itse

Re: Poor memory allocation performance with a lot of threads on 36 core machine

2016-02-18 Thread Witek via Digitalmars-d
On Thursday, 18 February 2016 at 13:49:45 UTC, Vladimir Panteleev wrote: On Thursday, 18 February 2016 at 13:00:12 UTC, Witek wrote: So, the question is, why is D / DMD allocator so slow under heavy multithreading? The working set is pretty small (few megabytes at most), so I do not think this

Poor memory allocation performance with a lot of threads on 36 core machine

2016-02-18 Thread Witek via Digitalmars-d
Hi, I was playing with std.parallelism, and implemented a parallel NQueens code to count number of solutions to the classical NQueens problem. I do limited parallel recursion using taskPool.parallel foreach, and then switch at some level to serial algorithm. I use return values / atomic varia