svn commit: r332365 - head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs

[Mark Johnston]

On Wed, Apr 11, 2018 at 12:51:55AM -0400, Allan Jude wrote:
> On 2018-04-10 09:56, Mark Johnston wrote:
> > Author: markj
> > Date: Tue Apr 10 13:56:06 2018
> > New Revision: 332365
> > URL: https://svnweb.freebsd.org/changeset/base/332365
> > 
> > Log:
> >   Set zfs_arc_free_target to v_free_target.
> >   
> >   Page daemon output is now regulated by a PID controller with a setpoint
> >   of v_free_target. Moreover, the page daemon now wakes up regularly
> >   rather than waiting for a wakeup from another thread. This means that
> >   the free page count is unlikely to drop below the old
> >   zfs_arc_free_target value, and as a result the ARC was not readily
> >   freeing pages under memory pressure. Address the immediate problem by
> >   updating zfs_arc_free_target to match the page daemon's new behaviour.
> >   
> >   Reported and tested by:	truckman
> >   Discussed with:	jeff
> >   X-MFC with:	r329882
> >   Differential Revision:	https://reviews.freebsd.org/D14994
> > 
> 
> On a somewhat unrelated note, can we rename this sysctl and change to be
> counted in bytes? When users are tuning ZFS, every other ZFS value is in
> bytes, not pages.
> 
> Maybe keep the currently variable as it is, in pages, and adjust it by
> dividing the user set value by the page size.
> 
> The current name is great, but I wouldn't want anyone to end up setting
> it to 4096x the value they actually want if we just changed it out from
> under them.

Sure, any suggestions for what the new sysctl should be named?