yea, I was wondering if that would start to cause problems someday.
calling pgo_flush() with a non-page-aligned address should really be
an error, since pgo_flush() needs to round differently depending on
what it's doing.  for PGO_CLEANIT we want to include partial pages
on the ends, for PGO_FREE we want to exclude them, and it doesn't
much matter for PGO_DEACTIVATE.  the caller ought to do the appropriate
rounding for the context so that pgo_flush() doesn't have to mess with it.

-Chuck


On Wed, Feb 21, 2001 at 02:56:07PM +0900, enami tsugutomo wrote:
> Chuck Silvers <chuq@chuq.com> writes:
> 
> > I'm guessing a better fix will be somewhere in the truncate path
> > rather than the write path, but I'm not sure what the actual bug is
> > yet.
> 
> It looks like uvm_vnp_setsize() tosses necessary page if newsize isn't
> on page boundary.
> 
> enami.
> Index: uvm_vnode.c
> ===================================================================
> RCS file: /cvsroot/syssrc/sys/uvm/uvm_vnode.c,v
> retrieving revision 1.45
> diff -u -r1.45 uvm_vnode.c
> --- uvm_vnode.c	2001/02/18 19:40:25	1.45
> +++ uvm_vnode.c	2001/02/21 05:53:08
> @@ -1015,6 +1015,7 @@
>  	voff_t newsize;
>  {
>  	struct uvm_vnode *uvn = &vp->v_uvm;
> +	voff_t pgend = round_page(newsize);
>  	UVMHIST_FUNC("uvm_vnp_setsize"); UVMHIST_CALLED(ubchist);
>  
>  	simple_lock(&uvn->u_obj.vmobjlock);
> @@ -1026,8 +1027,8 @@
>  	 * toss some pages...
>  	 */
>  
> -	if (uvn->u_size > newsize && uvn->u_size != VSIZENOTSET) {
> -		(void) uvn_flush(&uvn->u_obj, newsize, 0, PGO_FREE);
> +	if (uvn->u_size > pgend && uvn->u_size != VSIZENOTSET) {
> +		(void) uvn_flush(&uvn->u_obj, pgend, 0, PGO_FREE);
>  	}
>  	uvn->u_size = newsize;
>  	simple_unlock(&uvn->u_obj.vmobjlock);