Author: dougm Date: Thu Jun 13 20:09:07 2019 New Revision: 349023 URL: https://svnweb.freebsd.org/changeset/base/349023
Log: Create a function for creating objects to back map entries, and one for giving cred to a map entry backed by an object, and use them instead of the code duplicated inline now. Approved by: kib (mentor) Differential Revision: https://reviews.freebsd.org/D20370 Modified: head/sys/vm/vm_map.c Modified: head/sys/vm/vm_map.c ============================================================================== --- head/sys/vm/vm_map.c Thu Jun 13 19:51:48 2019 (r349022) +++ head/sys/vm/vm_map.c Thu Jun 13 20:09:07 2019 (r349023) @@ -2109,6 +2109,60 @@ vm_map_simplify_entry(vm_map_t map, vm_map_entry_t ent } /* + * vm_map_entry_back: + * + * Allocate an object to back a map entry. + */ +static inline void +vm_map_entry_back(vm_map_entry_t entry) +{ + vm_object_t object; + + KASSERT(entry->object.vm_object == NULL, + ("map entry %p has backing object", entry)); + KASSERT((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0, + ("map entry %p is a submap", entry)); + object = vm_object_allocate(OBJT_DEFAULT, + atop(entry->end - entry->start)); + entry->object.vm_object = object; + entry->offset = 0; + if (entry->cred != NULL) { + object->cred = entry->cred; + object->charge = entry->end - entry->start; + entry->cred = NULL; + } +} + +/* + * vm_map_entry_charge_object + * + * If there is no object backing this entry, create one. Otherwise, if + * the entry has cred, give it to the backing object. + */ +static inline void +vm_map_entry_charge_object(vm_map_t map, vm_map_entry_t entry) +{ + + VM_MAP_ASSERT_LOCKED(map); + KASSERT((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0, + ("map entry %p is a submap", entry)); + if (entry->object.vm_object == NULL && !map->system_map && + (entry->eflags & MAP_ENTRY_GUARD) == 0) + vm_map_entry_back(entry); + else if (entry->object.vm_object != NULL && + ((entry->eflags & MAP_ENTRY_NEEDS_COPY) == 0) && + entry->cred != NULL) { + VM_OBJECT_WLOCK(entry->object.vm_object); + KASSERT(entry->object.vm_object->cred == NULL, + ("OVERCOMMIT: %s: both cred e %p", __func__, entry)); + entry->object.vm_object->cred = entry->cred; + entry->object.vm_object->charge = entry->end - entry->start; + VM_OBJECT_WUNLOCK(entry->object.vm_object); + entry->cred = NULL; + } +} + +/* * vm_map_clip_start: [ internal use only ] * * Asserts that the given entry begins at or after @@ -2140,38 +2194,7 @@ _vm_map_clip_start(vm_map_t map, vm_map_entry_t entry, * starting address. */ vm_map_simplify_entry(map, entry); - - /* - * If there is no object backing this entry, we might as well create - * one now. If we defer it, an object can get created after the map - * is clipped, and individual objects will be created for the split-up - * map. This is a bit of a hack, but is also about the best place to - * put this improvement. - */ - if (entry->object.vm_object == NULL && !map->system_map && - (entry->eflags & MAP_ENTRY_GUARD) == 0) { - vm_object_t object; - object = vm_object_allocate(OBJT_DEFAULT, - atop(entry->end - entry->start)); - entry->object.vm_object = object; - entry->offset = 0; - if (entry->cred != NULL) { - object->cred = entry->cred; - object->charge = entry->end - entry->start; - entry->cred = NULL; - } - } else if (entry->object.vm_object != NULL && - ((entry->eflags & MAP_ENTRY_NEEDS_COPY) == 0) && - entry->cred != NULL) { - VM_OBJECT_WLOCK(entry->object.vm_object); - KASSERT(entry->object.vm_object->cred == NULL, - ("OVERCOMMIT: vm_entry_clip_start: both cred e %p", entry)); - entry->object.vm_object->cred = entry->cred; - entry->object.vm_object->charge = entry->end - entry->start; - VM_OBJECT_WUNLOCK(entry->object.vm_object); - entry->cred = NULL; - } - + vm_map_entry_charge_object(map, entry); new_entry = vm_map_entry_create(map); *new_entry = *entry; @@ -2222,40 +2245,11 @@ _vm_map_clip_end(vm_map_t map, vm_map_entry_t entry, v KASSERT(entry->start < end && entry->end > end, ("_vm_map_clip_end: invalid clip of entry %p", entry)); - /* - * If there is no object backing this entry, we might as well create - * one now. If we defer it, an object can get created after the map - * is clipped, and individual objects will be created for the split-up - * map. This is a bit of a hack, but is also about the best place to - * put this improvement. - */ - if (entry->object.vm_object == NULL && !map->system_map && - (entry->eflags & MAP_ENTRY_GUARD) == 0) { - vm_object_t object; - object = vm_object_allocate(OBJT_DEFAULT, - atop(entry->end - entry->start)); - entry->object.vm_object = object; - entry->offset = 0; - if (entry->cred != NULL) { - object->cred = entry->cred; - object->charge = entry->end - entry->start; - entry->cred = NULL; - } - } else if (entry->object.vm_object != NULL && - ((entry->eflags & MAP_ENTRY_NEEDS_COPY) == 0) && - entry->cred != NULL) { - VM_OBJECT_WLOCK(entry->object.vm_object); - KASSERT(entry->object.vm_object->cred == NULL, - ("OVERCOMMIT: vm_entry_clip_end: both cred e %p", entry)); - entry->object.vm_object->cred = entry->cred; - entry->object.vm_object->charge = entry->end - entry->start; - VM_OBJECT_WUNLOCK(entry->object.vm_object); - entry->cred = NULL; - } /* * Create a new entry and insert it AFTER the specified entry */ + vm_map_entry_charge_object(map, entry); new_entry = vm_map_entry_create(map); *new_entry = *entry; @@ -3935,16 +3929,8 @@ vmspace_fork(struct vmspace *vm1, vm_ooffset_t *fork_c */ object = old_entry->object.vm_object; if (object == NULL) { - object = vm_object_allocate(OBJT_DEFAULT, - atop(old_entry->end - old_entry->start)); - old_entry->object.vm_object = object; - old_entry->offset = 0; - if (old_entry->cred != NULL) { - object->cred = old_entry->cred; - object->charge = old_entry->end - - old_entry->start; - old_entry->cred = NULL; - } + vm_map_entry_back(old_entry); + object = old_entry->object.vm_object; } /* _______________________________________________ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
