On 2015-10-13 07:14:01 -0700, Shaun Thomas wrote: > On Tue, Oct 13, 2015 at 2:32 AM, Heikki Linnakangas <hlinnaka@xxxxxx> wrote: > > 80% of the CPU time is spent in the b-tree comparison function. > > In the logs, my duration per COPY command increases from about 1400ms > for one process to about 3800ms when I have four running concurrently. > That's really my only data point, unfortunately. Strace isn't super > helpful because it just says 70-ish% of the time is wait4, but that's > not significantly different than the results using one process. Please run a profile. Compile postgres with CFLAGS='-O2 -fno-omit-frame-pointer' as an argument to configure. That'll allow us to get a hierarchical profile. Then first do a plain cpu profile: perf record -g -a sleep 5 perf report > somefile Then let's look at lock contention: perf record -g -a -e syscalls:sys_enter_semop sleep 5 perf report > somefile and send the results. Thanks, Andres -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
