Re: [OMPI devel] kernel 2.6.23 vs 2.6.24 - communication/wait times

2010-04-10 Thread Ashley Pittman
On 10 Apr 2010, at 04:51, Eugene Loh wrote: > Why is shared-memory performance about four orders of magnitude slower than > it should be? The processes are communicating via memory that's shared by > having the processes all mmap the same file into their address spaces. Is it > possible that

Re: [OMPI devel] kernel 2.6.23 vs 2.6.24 - communication/wait times

2010-04-10 Thread Eugene Loh
Bogdan Costescu wrote: On Sat, Apr 10, 2010 at 5:51 AM, Eugene Loh wrote: Why is shared-memory performance about four orders of magnitude slower than it should be? Have there been any process scheduler changes in the newer kernels ? I'm not sure that they could explain f

Re: [OMPI devel] kernel 2.6.23 vs 2.6.24 - communication/wait times

2010-04-10 Thread Bogdan Costescu
On Sat, Apr 10, 2010 at 5:51 AM, Eugene Loh wrote: > Why is shared-memory performance about four orders of magnitude slower than > it should be? Have there been any process scheduler changes in the newer kernels ? I'm not sure that they could explain four orders of magnitude differences though...