Author: kib
Date: Sun Jul 10 04:33:16 2016
New Revision: 302513
URL: https://svnweb.freebsd.org/changeset/base/302513
Log:
MFC r302236:
Handle the vm_fault() handler race with the vm_object_collapse()
sleepable scan.
MFC r302317:
Change type of the 'dead' variable to boolean.
Modified:
stable/10/sys/vm/vm_fault.c
Directory Properties:
stable/10/ (props changed)
Modified: stable/10/sys/vm/vm_fault.c
==============================================================================
--- stable/10/sys/vm/vm_fault.c Sun Jul 10 03:49:38 2016 (r302512)
+++ stable/10/sys/vm/vm_fault.c Sun Jul 10 04:33:16 2016 (r302513)
@@ -286,7 +286,7 @@ vm_fault_hold(vm_map_t map, vm_offset_t
vm_prot_t prot;
long ahead, behind;
int alloc_req, era, faultcount, nera, reqpage, result;
- boolean_t growstack, is_first_object_locked, wired;
+ boolean_t dead, growstack, is_first_object_locked, wired;
int map_generation;
vm_object_t next_object;
vm_page_t marray[VM_FAULT_READ_MAX];
@@ -423,11 +423,18 @@ fast_failed:
fs.pindex = fs.first_pindex;
while (TRUE) {
/*
- * If the object is dead, we stop here
+ * If the object is marked for imminent termination,
+ * we retry here, since the collapse pass has raced
+ * with us. Otherwise, if we see terminally dead
+ * object, return fail.
*/
- if (fs.object->flags & OBJ_DEAD) {
+ if ((fs.object->flags & OBJ_DEAD) != 0) {
+ dead = fs.object->type == OBJT_DEAD;
unlock_and_deallocate(&fs);
- return (KERN_PROTECTION_FAILURE);
+ if (dead)
+ return (KERN_PROTECTION_FAILURE);
+ pause("vmf_de", 1);
+ goto RetryFault;
}
/*
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