2011/1/12 Achilleas Mantzios <ach...@matrix.gatewaynet.com>: > > Changed that to smth like: micros_total = micros_total + (double) micros; > instead of the printf to beat any compiler optimization, and still linux runs > at light speed: > FBSD_TEST : user 0.089s, sys 1.4s > FBSD_DEV : user 0.183s, sys 3.8s > LINUX_PROD : user 0.168s, sys 0s > (regarding that gettimeofday is a syscall in FreeBSD, and that sys time is 0 > for linux, makes me think some optimization is being done)
At least on x86_64, linux will use a vsyscall (v for virtual) for gettimeofday which does not actually need to enter/exit the kernel. That probably explains a large part of the speed difference here. -- Sent via pgsql-admin mailing list (pgsql-admin@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-admin
