On Fri, 07 Apr 2006 17:56:49 -0400 Tom Lane <tgl@xxxxxxxxxxxxx> wrote: > This is not good. Did the semop storms coincide with visible > slowdown? (I'd assume so, but you didn't actually say...) If I'd been able to tell, then I'd tell you =) I'll have another go... Yes, there's a definate correlation here.. I attached truss to the main postmaster.. $ truss -Ff -p 340344 2>&1 | grep semop here's a snippet 278774: __semop(15728650, 0x0FFFFFFFFFFF7E80, 1) = 0 155712: __semop(15728650, 0x0FFFFFFFFFFF5920, 1) = 0 278774: __semop(15728649, 0x0FFFFFFFFFFF6F10, 1) 114914: __semop(15728649, 0x0FFFFFFFFFFF6A40, 1) = 0 = 0 114914: __semop(15728650, 0x0FFFFFFFFFFF61E0, 1) 155712: __semop(15728650, 0x0FFFFFFFFFFF6850, 1) = 0 = 0 155712: __semop(15728650, 0x0FFFFFFFFFFF6890, 1) = 0 1 55712: __semop(15728650, 0x0FFFFFFFFFFF5920, 1) 278774: __semop(15728650, 0x0FFFFFFFFFFF6F10, 1) 155712: __semop(15728650, 0x0FFFFFFFFFFF6850, 1) = 0 = 0 278774: __semop(15728649, 0x0FFFFFFFFFFF7E40, 1) 114914: __semop(15728649, 0x0FFFFFFFFFFF6A80, 1) = 0 = 0 278774: __semop(15728650, 0x0FFFFFFFFFFF7E80, 1) And when I saw a flood of semop's for any particular PID, a second later in the 'topas' process list would show that PID at a 100% CPU ... Most intriguing :) Cheers, Gavin.
