9.1 AMD64 multitasking efficiency low

[Shane Ambler]

I have two WD's a 1TB and a 2TB. Upgraded to 9.1 three days ago and
don't think it is any worse than 9.0. I find things slow down if two
things are trying to access the drive at the same time and when I do get
some swapping it gets unbearable. One thing that always annoyed me was
the security scans that start early morning, they make any tinderbox
builds I leave running grind to a halt. They also run shortly after 
startup - and they show little cpu usage.

Disable them by adding to /etc/periodic.conf
daily_status_security_chksetuid_enable="NO"
daily_status_security_neggrpperm_enable="NO"

I'm sure the first one is a long scan but haven't verified the second.

I think I recall the aio module made a difference for me. I believe
kldload aio will make it active straight away - if not aio_load="YES"
in /etc/loader.conf to load at boot


I have a desktop machine - ASUS P8H61-M/LE corei5 8GB

ada0 at ahcich0 bus 0 scbus0 target 0 lun 0
ada0: <WDC WD20EARX-00PASB0 51.0AB51> ATA-8 SATA 3.x device
ada0: 300.000MB/s transfers (SATA 2.x, UDMA6, PIO 8192bytes)
ada0: Command Queueing enabled
ada0: 1907729MB (3907029168 512 byte sectors: 16H 63S/T 16383C)
ada0: Previously was known as ad4

ada1 at ahcich4 bus 0 scbus2 target 0 lun 0
ada1: <WDC WD10EARS-00Y5B1 80.00A80> ATA-8 SATA 2.x device
ada1: 300.000MB/s transfers (SATA 2.x, UDMA6, PIO 8192bytes)
ada1: Command Queueing enabled
ada1: 953869MB (1953525168 512 byte sectors: 16H 63S/T 16383C)
ada1: Previously was known as ad8