Author: dougm Date: Wed Dec 11 16:09:57 2019 New Revision: 355612 URL: https://svnweb.freebsd.org/changeset/base/355612
Log: Extract code common to _vm_map_clip_start and _vm_map_clip_end into a function, vm_map_entry_clone, that can be invoked by each. Reviewed by: kib, markj Differential Revision: https://reviews.freebsd.org/D22760 Modified: head/sys/vm/vm_map.c Modified: head/sys/vm/vm_map.c ============================================================================== --- head/sys/vm/vm_map.c Wed Dec 11 15:52:29 2019 (r355611) +++ head/sys/vm/vm_map.c Wed Dec 11 16:09:57 2019 (r355612) @@ -2291,6 +2291,42 @@ vm_map_entry_charge_object(vm_map_t map, vm_map_entry_ } /* + * vm_map_entry_clone + * + * Create a duplicate map entry for clipping. + */ +static vm_map_entry_t +vm_map_entry_clone(vm_map_t map, vm_map_entry_t entry) +{ + vm_map_entry_t new_entry; + + VM_MAP_ASSERT_LOCKED(map); + + /* + * Create a backing object now, if none exists, so that more individual + * objects won't be created after the map entry is split. + */ + vm_map_entry_charge_object(map, entry); + + /* Clone the entry. */ + new_entry = vm_map_entry_create(map); + *new_entry = *entry; + if (new_entry->cred != NULL) + crhold(entry->cred); + if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0) { + vm_object_reference(new_entry->object.vm_object); + vm_map_entry_set_vnode_text(new_entry, true); + /* + * The object->un_pager.vnp.writemappings for the object of + * MAP_ENTRY_WRITECNT type entry shall be kept as is here. The + * virtual pages are re-distributed among the clipped entries, + * so the sum is left the same. + */ + } + return (new_entry); +} + +/* * vm_map_clip_start: [ internal use only ] * * Asserts that the given entry begins at or after @@ -2316,16 +2352,8 @@ _vm_map_clip_start(vm_map_t map, vm_map_entry_t entry, KASSERT(entry->end > start && entry->start < start, ("_vm_map_clip_start: invalid clip of entry %p", entry)); - /* - * Create a backing object now, if none exists, so that more individual - * objects won't be created after the map entry is split. - */ - vm_map_entry_charge_object(map, entry); + new_entry = vm_map_entry_clone(map, entry); - /* Clone the entry. */ - new_entry = vm_map_entry_create(map); - *new_entry = *entry; - /* * Split off the front portion. Insert the new entry BEFORE this one, * so that this entry has the specified starting address. @@ -2333,22 +2361,7 @@ _vm_map_clip_start(vm_map_t map, vm_map_entry_t entry, new_entry->end = start; entry->offset += (start - entry->start); entry->start = start; - if (new_entry->cred != NULL) - crhold(entry->cred); - vm_map_entry_link(map, new_entry); - - if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0) { - vm_object_reference(new_entry->object.vm_object); - vm_map_entry_set_vnode_text(new_entry, true); - /* - * The object->un_pager.vnp.writemappings for the - * object of MAP_ENTRY_WRITECNT type entry shall be - * kept as is here. The virtual pages are - * re-distributed among the clipped entries, so the sum is - * left the same. - */ - } } /* @@ -2377,31 +2390,15 @@ _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)); - /* - * Create a backing object now, if none exists, so that more individual - * objects won't be created after the map entry is split. - */ - vm_map_entry_charge_object(map, entry); + new_entry = vm_map_entry_clone(map, entry); - /* Clone the entry. */ - new_entry = vm_map_entry_create(map); - *new_entry = *entry; - /* * Split off the back portion. Insert the new entry AFTER this one, * so that this entry has the specified ending address. */ new_entry->start = entry->end = end; new_entry->offset += (end - entry->start); - if (new_entry->cred != NULL) - crhold(entry->cred); - vm_map_entry_link(map, new_entry); - - if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0) { - vm_object_reference(new_entry->object.vm_object); - vm_map_entry_set_vnode_text(new_entry, true); - } } /* _______________________________________________ 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"
