On 01/12/20(Tue) 15:18, Mark Kettenis wrote:
> > Date: Tue, 1 Dec 2020 11:08:50 -0300
> > From: Martin Pieuchot <[email protected]>
> >
> > As recently pointed out by jmatthew@ these need the lock as well, ok?
>
> No. These pages are "unmanaged" and therefore they can not be on any
> of the page queues and locking those page queues would be pointless.
>
> We probably should adjust the documentation to reflect this.
Something like that?
Btw did you look at the uses of uvm_pagefree(), uvm_pagelookup() & co in
the various pmap? Do you have any suggestion about how to handle them?
Index: uvm/uvm_page.c
===================================================================
RCS file: /cvs/src/sys/uvm/uvm_page.c,v
retrieving revision 1.153
diff -u -p -r1.153 uvm_page.c
--- uvm/uvm_page.c 1 Dec 2020 13:56:22 -0000 1.153
+++ uvm/uvm_page.c 1 Dec 2020 16:16:29 -0000
@@ -928,7 +928,7 @@ uvm_pagerealloc(struct vm_page *pg, stru
* uvm_pageclean: clean page
*
* => erase page's identity (i.e. remove from object)
- * => caller must lock page queues
+ * => caller must lock page queues if `pg' is managed
* => assumes all valid mappings of pg are gone
*/
void
@@ -937,7 +937,8 @@ uvm_pageclean(struct vm_page *pg)
u_int flags_to_clear = 0;
#if all_pmap_are_fixed
- MUTEX_ASSERT_LOCKED(&uvm.pageqlock);
+ if (pg->pg_flags & (PG_TABLED|PQ_ACTIVE|PQ_INACTIVE))
+ MUTEX_ASSERT_LOCKED(&uvm.pageqlock);
#endif
#ifdef DEBUG
@@ -998,14 +999,15 @@ uvm_pageclean(struct vm_page *pg)
*
* => erase page's identity (i.e. remove from object)
* => put page on free list
- * => caller must lock page queues
+ * => caller must lock page queues if `pg' is managed
* => assumes all valid mappings of pg are gone
*/
void
uvm_pagefree(struct vm_page *pg)
{
#if all_pmap_are_fixed
- MUTEX_ASSERT_LOCKED(&uvm.pageqlock);
+ if (pg->pg_flags & (PG_TABLED|PQ_ACTIVE|PQ_INACTIVE))
+ MUTEX_ASSERT_LOCKED(&uvm.pageqlock);
#endif
uvm_pageclean(pg);
