Current-Users archive

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Old Index]

Re: Global page into user processes (was: Re: Patch to cache TLS in %fp7 to avoid _lwp_getprivate syscalls)

On Wed, 18 Jan 2012 22:43:18 +0100
Joerg Sonnenberger <> wrote:

> On Wed, Jan 18, 2012 at 03:20:57PM -0500, Matthew Mondor wrote:
> > I noticed that the KERN_HARDCLOCK_TICKS sysctl(3) is still quite faster
> > than gettimeofday(2) (although it only exports a single int, the
> > hardclock(9)):
> Well, what timer are you using? Unless it is TSC or LAPIC, it is going
> to take significantly longer than the system call overhead or just
> reading a global variable.

This was with TSC.  But the KERN_HARDCLOCK_TICKS sysctl knob appears
to export the hardclock_ticks global variable (at least on netbsd-5).

Home | Main Index | Thread Index | Old Index