From: Theo Buehler <tb@openbsd.org>
Subject: Re: Use uvm_pagewait()
To: tech@openbsd.org
Date: Mon, 2 Dec 2024 14:24:23 +0100

On Mon, Dec 02, 2024 at 01:33:55PM +0100, Martin Pieuchot wrote:
> Use uvm_pagewait() instead of re-rolling it.  This helps grepping for
> places that set the PG_WANTED flag.
> 
> ok?

ok tb

> 
> Index: uvm/uvm_fault.c
> ===================================================================
> RCS file: /cvs/src/sys/uvm/uvm_fault.c,v
> diff -u -p -r1.148 uvm_fault.c
> --- uvm/uvm_fault.c	29 Nov 2024 06:44:57 -0000	1.148
> +++ uvm/uvm_fault.c	2 Dec 2024 12:14:54 -0000
> @@ -316,7 +316,6 @@ uvmfault_anonget(struct uvm_faultinfo *u
>  			 */
>  			if ((pg->pg_flags & (PG_BUSY|PG_RELEASED)) == 0)
>  				return 0;
> -			atomic_setbits_int(&pg->pg_flags, PG_WANTED);
>  			counters_inc(uvmexp_counters, flt_pgwait);
>  
>  			/*
> @@ -326,13 +325,12 @@ uvmfault_anonget(struct uvm_faultinfo *u
>  			if (pg->uobject) {
>  				/* Owner of page is UVM object. */
>  				uvmfault_unlockall(ufi, amap, NULL);
> -				rwsleep_nsec(pg, pg->uobject->vmobjlock,
> -				    PVM | PNORELOCK, "anonget1", INFSLP);
> +				uvm_pagewait(pg, pg->uobject->vmobjlock,
> +				    "anonget1");
>  			} else {
>  				/* Owner of page is anon. */
>  				uvmfault_unlockall(ufi, NULL, NULL);
> -				rwsleep_nsec(pg, anon->an_lock, PVM | PNORELOCK,
> -				    "anonget2", INFSLP);
> +				uvm_pagewait(pg, anon->an_lock, "anonget2");
>  			}
>  		} else {
>  			/*
> 
>