svn commit: r208988 - in head/sys: kern sys

[John Baldwin]

On Friday 11 June 2010 4:31:37 am Kostik Belousov wrote:
> On Thu, Jun 10, 2010 at 04:14:05PM +0000, Alexander Motin wrote:
> > Author: mav
> > Date: Thu Jun 10 16:14:05 2010
> > New Revision: 208988
> > URL: http://svn.freebsd.org/changeset/base/208988
> > 
> > Log:
> >   Store interrupt trap frame into struct thread. It allows interrupt 
handler
> >   to obtain both trap frame and opaque argument submitted on registrction.
> >   After kernel and all drivers get used to it, legacy hack can be removed.
> >   
> >   Reviewed by:	jhb@
> Just curious, why td_frame is not enough for your usage ? I believe td_frame
> is currently set only by traps and syscalls, and copied on forks.

td_frame is not set on a nested interrupt.  Thus, if you use td_frame and get 
an interrupt while in a syscall, statclock() would account the time as a user 
tick instead of a system tick.

Put another way, td_frame always references the user --> system trapframe, but 
td_intr_frame will reference the most recent trapframe on the stack.

-- 
John Baldwin