diff options
Diffstat (limited to 'sys/vm/vm_map.c')
-rw-r--r-- | sys/vm/vm_map.c | 42 |
1 files changed, 41 insertions, 1 deletions
diff --git a/sys/vm/vm_map.c b/sys/vm/vm_map.c index 35552a6..1a51af8 100644 --- a/sys/vm/vm_map.c +++ b/sys/vm/vm_map.c @@ -671,6 +671,41 @@ vm_map_wakeup(vm_map_t map) wakeup(&map->root); } +void +vm_map_busy(vm_map_t map) +{ + + VM_MAP_ASSERT_LOCKED(map); + map->busy++; +} + +void +vm_map_unbusy(vm_map_t map) +{ + + VM_MAP_ASSERT_LOCKED(map); + KASSERT(map->busy, ("vm_map_unbusy: not busy")); + if (--map->busy == 0 && (map->flags & MAP_BUSY_WAKEUP)) { + vm_map_modflags(map, 0, MAP_BUSY_WAKEUP); + wakeup(&map->busy); + } +} + +void +vm_map_wait_busy(vm_map_t map) +{ + + VM_MAP_ASSERT_LOCKED(map); + while (map->busy) { + vm_map_modflags(map, MAP_BUSY_WAKEUP, 0); + if (map->system_map) + msleep(&map->busy, &map->system_mtx, 0, "mbusy", 0); + else + sx_sleep(&map->busy, &map->lock, 0, "mbusy", 0); + } + map->timestamp++; +} + long vmspace_resident_count(struct vmspace *vmspace) { @@ -718,6 +753,7 @@ _vm_map_init(vm_map_t map, pmap_t pmap, vm_offset_t min, vm_offset_t max) map->flags = 0; map->root = NULL; map->timestamp = 0; + map->busy = 0; } void @@ -2382,12 +2418,14 @@ vm_map_wire(vm_map_t map, vm_offset_t start, vm_offset_t end, entry->object.vm_object->type == OBJT_SG); /* * Release the map lock, relying on the in-transition - * mark. + * mark. Mark the map busy for fork. */ + vm_map_busy(map); vm_map_unlock(map); rv = vm_fault_wire(map, saved_start, saved_end, fictitious); vm_map_lock(map); + vm_map_unbusy(map); if (last_timestamp + 1 != map->timestamp) { /* * Look again for the entry because the map was @@ -2995,6 +3033,8 @@ vmspace_fork(struct vmspace *vm1, vm_ooffset_t *fork_charge) int locked; vm_map_lock(old_map); + if (old_map->busy) + vm_map_wait_busy(old_map); vm2 = vmspace_alloc(old_map->min_offset, old_map->max_offset); if (vm2 == NULL) goto unlock_and_return; |