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Remove unnecessary page protects on map_split and collapse operations.

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Fix bug where an object's OBJ_WRITEABLE/OBJ_MIGHTBEDIRTY flags do
    not get set under certain circumstances ( page rename case ).

Reviewed by:	Alan Cox <alc@cs.rice.edu>, John Dyson
This commit is contained in:
Matthew Dillon 1999-02-24 21:26:26 +00:00
parent bf18286593
commit d1bf5d56b6
3 changed files with 16 additions and 6 deletions
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6
sys/vm/vm_map.c
View File

@ -61,7 +61,7 @@
* any improvements or extensions that they make and grant Carnegie the
* rights to redistribute these changes.
*
* $Id: vm_map.c,v 1.150 1999/02/19 03:11:37 dillon Exp $
* $Id: vm_map.c,v 1.151 1999/02/19 14:25:36 luoqi Exp $
*/
/*
@ -2162,12 +2162,14 @@ vm_map_split(entry)
/*
* We must wait for pending I/O to complete before we can
* rename the page.
*
* We do not have to VM_PROT_NONE the page as mappings should
* not be changed by this operation.
*/
if (vm_page_sleep_busy(m, TRUE, "spltwt"))
goto retry;
vm_page_busy(m);
vm_page_protect(m, VM_PROT_NONE);
vm_page_rename(m, new_object, idx);
/* page automatically made dirty by rename and cache handled */
vm_page_busy(m);

7
sys/vm/vm_object.c
View File

@ -61,7 +61,7 @@
* any improvements or extensions that they make and grant Carnegie the
* rights to redistribute these changes.
*
* $Id: vm_object.c,v 1.150 1999/02/12 20:42:19 dillon Exp $
* $Id: vm_object.c,v 1.151 1999/02/15 02:03:40 dillon Exp $
*/
/*
@ -1086,11 +1086,12 @@ vm_object_backing_scan(vm_object_t object, int op)
/*
* Page does not exist in parent, rename the
* page from the backing object to the main object.
*
* If the page was mapped to a process, it can remain
* mapped through the rename.
*/
if ((p->queue - p->pc) == PQ_CACHE)
vm_page_deactivate(p);
else
vm_page_protect(p, VM_PROT_NONE);
vm_page_rename(p, object, new_pindex);
/* page automatically made dirty by rename */

9
sys/vm/vm_page.c
View File

@ -34,7 +34,7 @@
* SUCH DAMAGE.
*
* from: @(#)vm_page.c 7.4 (Berkeley) 5/7/91
* $Id: vm_page.c,v 1.125 1999/02/08 00:37:35 dillon Exp $
* $Id: vm_page.c,v 1.126 1999/02/15 06:52:14 dillon Exp $
*/
/*
@ -425,6 +425,13 @@ vm_page_insert(m, object, pindex)
*/
object->resident_page_count++;
/*
* Since we are inserting a new and possibly dirty page,
* update the object's OBJ_WRITEABLE and OBJ_MIGHTBEDIRTY flags.
*/
if (m->flags & PG_WRITEABLE)
vm_object_set_flag(object, OBJ_WRITEABLE|OBJ_MIGHTBEDIRTY);
}
/*