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 with the newer kernels, operations to that shared file are > going all the way out to disk? Maybe you don't know the answer, but > hopefully someone on this mail list can provide some insight.
Is the /tmp filesystem on NFS by any chance? Ashley, -- Ashley Pittman, Bath, UK. Padb - A parallel job inspection tool for cluster computing http://padb.pittman.org.uk
