svn commit: r186182 - head/sys/dev/ata

[Scott Long]

Alexander Motin wrote:
> Author: mav
> Date: Tue Dec 16 16:04:40 2008
> New Revision: 186182
> URL: http://svn.freebsd.org/changeset/base/186182
> 
> Log:
>   Call ata_legacy() only once on attach and save it's result. Scanning PCI
>   configuration registers (which are not going to change) on every interrupt
>   looks expensive, especially when interrupt is shared. Profiling shows me 3%
>   of time spent by atapci0 on pure network load due to IRQ sharing with em0.
> 

Nice change.  PCI Config registers are exceptionally slow to access on 
most systems.

Scott