Mark Kirkwood <mark.kirkwood@xxxxxxxxxxxxxxx> wrote: > On 11/07/14 20:22, Andres Freund wrote: >> So, the majority of the time is spent in numa page migration. >> Can you disable numa_balancing? I'm not sure if your kernel >> version does that at runtime or whether you need to reboot. >> The kernel.numa_balancing sysctl might work. Otherwise you >> probably need to boot with numa_balancing=0. >> >> It'd also be worthwhile to test this with numactl --interleave. > > That was my feeling too - but I had no idea what the magic switch > was to tame it (appears to be in 3.13 kernels), will experiment > and report back. Thanks again! It might be worth a test using a cpuset to interleave OS cache and the NUMA patch I submitted to the current CF to see whether this is getting into territory where the patch makes a bigger difference. I would expect it to do much better than using numactl --interleave because work_mem and other process-local memory would be allocated in "near" memory for each process. http://www.postgresql.org/message-id/1402267501.41111.YahooMailNeo@xxxxxxxxxxxxxxxxxxxxxxxxxxxx -- Kevin Grittner EDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company
