should we use atomic instructions to manipulate vmstats.v_wire_count?

Nicolas Thery nthery at gmail.com
Sun Jan 13 05:20:27 PST 2008


2008/1/13, Simon 'corecode' Schubert <corecode at fs.ei.tum.de>:
> Nicolas Thery wrote:
> > I noticed that vmstats.v_wire_count is incremented and decremented w/o
> > protection.  In contrast, atomic instructions (from <atomic.h>) are
> > used in freebsd.
> >
> > Is it a bug in dfly or is it intentional?
>
> As far as I understand, we're requiring the mplock for vm operations, so that should be covered.

Ok but what about zget() called from zalloc() which increments
v_wire_count?   I reckon zalloc() can be called w/o holding the
mplock.

Cheers,
Nicolas





More information about the Kernel mailing list