CPU on the server shows approx 60% used/40 % idle vmstat 5 5 procs -----------memory---------- ---swap-- -----io---- --system-- -----cpu----- r b swpd free buff cache si so bi bo in cs us sy id wa st 18 0 0 160465072 455200 352185248 0 0 37 421 2 0 4 1 95 0 0 14 1 0 160321088 455200 352315040 0 0 0 30559 30496 48583 48 4 46 1 0 1 0 0 160153584 455204 352466624 0 0 13 57266 35147 56949 56 5 38 2 0 19 1 0 160030544 455204 352577504 0 0 13 27765 27924 41981 41 3 54 1 0 10 0 0 159862800 455204 352731776 0 0 29 37807 35591 58193 57 5 37 2 0 A snapshot of 'perf' output for one of the users below. It doesnt change much from that profile. PerfTop: 319 irqs/sec kernel: 7.5% exact: 0.0% [1000Hz cycles], (target_pid: 18450) --------------------------------------------------------------------------------------------------------------------------------------------- samples pcnt function DSO _______ _____ ___________________________ ________________________________________________ 235.00 7.5% AllocSetAlloc /post/PostgreSQL2/postgresql-9.2rc1/bin/postgres 155.00 5.0% SearchCatCache /post/PostgreSQL2/postgresql-9.2rc1/bin/postgres 134.00 4.3% hash_search_with_hash_value /post/PostgreSQL2/postgresql-9.2rc1/bin/postgres 128.00 4.1% LWLockAcquire /post/PostgreSQL2/postgresql-9.2rc1/bin/postgres 110.00 3.5% _bt_compare /post/PostgreSQL2/postgresql-9.2rc1/bin/postgres 106.00 3.4% __memcpy_ssse3_back /lib64/libc-2.12.so 106.00 3.4% XLogInsert /post/PostgreSQL2/postgresql-9.2rc1/bin/postgres 92.00 2.9% cmp_numerics /post/PostgreSQL2/postgresql-9.2rc1/bin/postgres 73.00 2.3% ExecInitExpr /post/PostgreSQL2/postgresql-9.2rc1/bin/postgres 64.00 2.0% MemoryContextAlloc /post/PostgreSQL2/postgresql-9.2rc1/bin/postgres 61.00 1.9% GetSnapshotData /post/PostgreSQL2/postgresql-9.2rc1/bin/postgres 60.00 1.9% _int_malloc /lib64/libc-2.12.so 58.00 1.9% nocache_index_getattr /post/PostgreSQL2/postgresql-9.2rc1/bin/postgres 49.00 1.6% PinBuffer /post/PostgreSQL2/postgresql-9.2rc1/bin/postgres 49.00 1.6% cmp_abs_common /post/PostgreSQL2/postgresql-9.2rc1/bin/postgres -- View this message in context: http://postgresql.1045698.n5.nabble.com/Newbie-performance-problem-semop-taking-most-of-time-tp5724566p5725062.html Sent from the PostgreSQL - performance mailing list archive at Nabble.com. -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance