> Date: Wed, 3 Feb 2010 14:41:04 +0000
> From: Owain Ainsworth <zer...@googlemail.com>
>
> On Mon, Feb 01, 2010 at 11:30:06PM -0500, Ted Unangst wrote:
> > I think this fixes the problem with sleeping and holding pseg_lck.
> >
> > Index: uvm_extern.h
> > ===================================================================
> > RCS file: /home/tedu/cvs/src/sys/uvm/uvm_extern.h,v
> > retrieving revision 1.82
> > diff -u -r1.82 uvm_extern.h
> > --- uvm_extern.h 11 Aug 2009 18:43:33 -0000 1.82
> > +++ uvm_extern.h 2 Feb 2010 04:28:09 -0000
> > @@ -517,8 +517,9 @@
> > vaddr_t *, vsize_t, int,
> > boolean_t, vm_map_t);
> > vaddr_t uvm_km_valloc(vm_map_t, vsize_t);
> > -vaddr_t uvm_km_valloc_align(vm_map_t, vsize_t, vsize_t);
> > +vaddr_t uvm_km_valloc_try(vm_map_t, vsize_t);
> > vaddr_t uvm_km_valloc_wait(vm_map_t, vsize_t);
> > +vaddr_t uvm_km_valloc_align(struct vm_map *, vsize_t,
> > vsize_t, int);
> > vaddr_t uvm_km_valloc_prefer_wait(vm_map_t, vsize_t,
> > voff_t);
> > void *uvm_km_getpage(boolean_t, int *);
> > Index: uvm_km.c
> > ===================================================================
> > RCS file: /home/tedu/cvs/src/sys/uvm/uvm_km.c,v
> > retrieving revision 1.75
> > diff -u -r1.75 uvm_km.c
> > --- uvm_km.c 25 Jul 2009 12:55:40 -0000 1.75
> > +++ uvm_km.c 2 Feb 2010 04:27:35 -0000
> > @@ -571,11 +571,17 @@
> > vaddr_t
> > uvm_km_valloc(struct vm_map *map, vsize_t size)
> > {
> > - return(uvm_km_valloc_align(map, size, 0));
> > + return(uvm_km_valloc_align(map, size, 0, 0));
> > }
> >
> > vaddr_t
> > -uvm_km_valloc_align(struct vm_map *map, vsize_t size, vsize_t align)
> > +uvm_km_valloc_try(struct vm_map *map, vsize_t size)
> > +{
> > + return(uvm_km_valloc_align(map, size, 0, UVM_FLAG_TRYLOCK));
> > +}
> > +
> > +vaddr_t
> > +uvm_km_valloc_align(struct vm_map *map, vsize_t size, vsize_t align, int
> > flags)
> > {
> > vaddr_t kva;
> > UVMHIST_FUNC("uvm_km_valloc"); UVMHIST_CALLED(maphist);
> > @@ -592,7 +598,7 @@
> >
> > if (__predict_false(uvm_map(map, &kva, size, uvm.kernel_object,
> > UVM_UNKNOWN_OFFSET, align, UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL,
> > - UVM_INH_NONE, UVM_ADV_RANDOM, 0)) != 0)) {
> > + UVM_INH_NONE, UVM_ADV_RANDOM, flags)) != 0)) {
> > UVMHIST_LOG(maphist, "<- done (no VM)", 0,0,0,0);
> > return(0);
> > }
> > Index: uvm_pager.c
> > ===================================================================
> > RCS file: /home/tedu/cvs/src/sys/uvm/uvm_pager.c,v
> > retrieving revision 1.54
> > diff -u -r1.54 uvm_pager.c
> > --- uvm_pager.c 22 Jul 2009 21:05:37 -0000 1.54
> > +++ uvm_pager.c 2 Feb 2010 04:23:57 -0000
> > @@ -138,7 +138,7 @@
> > {
> > KASSERT(pseg->start == 0);
> > KASSERT(pseg->use == 0);
> > - pseg->start = uvm_km_valloc(kernel_map, MAX_PAGER_SEGS * MAXBSIZE);
> > + pseg->start = uvm_km_valloc_try(kernel_map, MAX_PAGER_SEGS * MAXBSIZE);
>
>
> this doesn't take into account the fact that valloc_try may fail and
> return 0.
That case is handled just fine. In uvm_pseg_get() we have a check
for pseg->start == 0 immediately after the uvm_pseg_init() call.
