From: Martin Pieuchot <mpi@grenadille.net>
Subject: Re: fail earlier in pgo_get
To: tech@openbsd.org
Date: Sat, 8 Nov 2025 17:23:34 +0000

On 27/10/25(Mon) 10:34, Martin Pieuchot wrote:
> Stop iterating as soon as a page is missing or busy when all pages are
> asked by the caller.
> 
> Note that currently pgo_get() is not called with PGO_ALLPAGES in the
> kernel.  This is a requirement for upcoming changes.
> 
> ok?

Anyone?

> Index: uvm/uvm_aobj.c
> ===================================================================
> RCS file: /cvs/src/sys/uvm/uvm_aobj.c,v
> diff -u -p -r1.116 uvm_aobj.c
> --- uvm/uvm_aobj.c	10 Mar 2025 14:13:58 -0000	1.116
> +++ uvm/uvm_aobj.c	27 Oct 2025 09:31:40 -0000
> @@ -1024,10 +1024,13 @@ uao_get(struct uvm_object *uobj, voff_t 
>  			 * to be useful must get a non-busy page
>  			 */
>  			if (ptmp == NULL || (ptmp->pg_flags & PG_BUSY) != 0) {
> -				if (lcv == centeridx ||
> -				    (flags & PGO_ALLPAGES) != 0)
> +				if (lcv == centeridx)
>  					/* need to do a wait or I/O! */
>  					done = FALSE;
> +				if ((flags & PGO_ALLPAGES) != 0) {
> +					done = FALSE;
> +					break;
> +				}
>  				continue;
>  			}
>  
> Index: uvm/uvm_vnode.c
> ===================================================================
> RCS file: /cvs/src/sys/uvm/uvm_vnode.c,v
> diff -u -p -r1.142 uvm_vnode.c
> --- uvm/uvm_vnode.c	29 Sep 2025 09:55:01 -0000	1.142
> +++ uvm/uvm_vnode.c	27 Oct 2025 09:32:09 -0000
> @@ -977,10 +990,13 @@ uvn_get(struct uvm_object *uobj, voff_t 
>  			 * to be useful must get a non-busy page
>  			 */
>  			if (ptmp == NULL || (ptmp->pg_flags & PG_BUSY) != 0) {
> -				if (lcv == centeridx ||
> -				    (flags & PGO_ALLPAGES) != 0)
> +				if (lcv == centeridx)
>  					/* need to do a wait or I/O! */
>  					done = FALSE;
> +				if ((flags & PGO_ALLPAGES) != 0) {
> +					done = FALSE;
> +					break;
> +				}
>  				continue;
>  			}
>  
> 
>