From 9bc3401c0d799e331e6eb05e8710997d8ab6229e Mon Sep 17 00:00:00 2001 From: niklas Date: Wed, 26 Mar 1997 18:45:31 +0000 Subject: [PATCH] Just some initial KNF in preparation for some other changes coming soon --- sys/vm/vm_object.c | 776 ++++++++++++++++++++++----------------------- 1 file changed, 386 insertions(+), 390 deletions(-) diff --git a/sys/vm/vm_object.c b/sys/vm/vm_object.c index 722d2f583b0..183d9bb0780 100644 --- a/sys/vm/vm_object.c +++ b/sys/vm/vm_object.c @@ -1,4 +1,4 @@ -/* $OpenBSD: vm_object.c,v 1.13 1996/12/24 20:14:28 niklas Exp $ */ +/* $OpenBSD: vm_object.c,v 1.14 1997/03/26 18:45:31 niklas Exp $ */ /* $NetBSD: vm_object.c,v 1.34 1996/02/28 22:35:35 gwr Exp $ */ /* @@ -79,28 +79,28 @@ #include /* - * Virtual memory objects maintain the actual data - * associated with allocated virtual memory. A given - * page of memory exists within exactly one object. + * Virtual memory objects maintain the actual data + * associated with allocated virtual memory. A given + * page of memory exists within exactly one object. * - * An object is only deallocated when all "references" - * are given up. Only one "reference" to a given - * region of an object should be writeable. + * An object is only deallocated when all "references" + * are given up. Only one "reference" to a given + * region of an object should be writeable. * - * Associated with each object is a list of all resident - * memory pages belonging to that object; this list is - * maintained by the "vm_page" module, and locked by the object's - * lock. + * Associated with each object is a list of all resident + * memory pages belonging to that object; this list is + * maintained by the "vm_page" module, and locked by the object's + * lock. * - * Each object also records a "pager" routine which is - * used to retrieve (and store) pages to the proper backing - * storage. In addition, objects may be backed by other - * objects from which they were virtual-copied. + * Each object also records a "pager" routine which is + * used to retrieve (and store) pages to the proper backing + * storage. In addition, objects may be backed by other + * objects from which they were virtual-copied. * - * The only items within the object structure which are - * modified after time of creation are: - * reference count locked by object's lock - * pager routine locked by object's lock + * The only items within the object structure which are + * modified after time of creation are: + * reference count locked by object's lock + * pager routine locked by object's lock * */ @@ -128,7 +128,7 @@ boolean_t vm_object_collapse_allowed = TRUE; int vmdebug = VMDEBUG; #endif -static void _vm_object_allocate __P((vm_size_t, vm_object_t)); +void _vm_object_allocate __P((vm_size_t, vm_object_t)); int vm_object_collapse_aux __P((vm_object_t)); int vm_object_bypass __P((vm_object_t)); void vm_object_set_shadow __P((vm_object_t, vm_object_t)); @@ -136,9 +136,9 @@ int vm_object_remove_from_pager __P((vm_object_t, vm_offset_t, vm_offset_t)); /* - * vm_object_init: + * vm_object_init: * - * Initialize the VM objects module. + * Initialize the VM objects module. */ void vm_object_init(size) @@ -163,9 +163,9 @@ vm_object_init(size) } /* - * vm_object_allocate: + * vm_object_allocate: * - * Returns a new object with the given size. + * Returns a new object with the given size. */ vm_object_t vm_object_allocate(size) @@ -173,15 +173,15 @@ vm_object_allocate(size) { register vm_object_t result; - result = (vm_object_t) - malloc((u_long)sizeof *result, M_VMOBJ, M_WAITOK); + result = (vm_object_t)malloc((u_long)sizeof *result, + M_VMOBJ, M_WAITOK); _vm_object_allocate(size, result); return(result); } -static void +void _vm_object_allocate(size, object) vm_size_t size; register vm_object_t object; @@ -213,9 +213,9 @@ _vm_object_allocate(size, object) } /* - * vm_object_reference: + * vm_object_reference: * - * Gets another reference to the given object. + * Gets another reference to the given object. */ void vm_object_reference(object) @@ -230,48 +230,48 @@ vm_object_reference(object) } /* - * vm_object_deallocate: + * vm_object_deallocate: * - * Release a reference to the specified object, - * gained either through a vm_object_allocate - * or a vm_object_reference call. When all references - * are gone, storage associated with this object - * may be relinquished. + * Release a reference to the specified object, + * gained either through a vm_object_allocate + * or a vm_object_reference call. When all references + * are gone, storage associated with this object + * may be relinquished. * - * No object may be locked. + * No object may be locked. */ void vm_object_deallocate(object) register vm_object_t object; { /* - * While "temp" is used for other things as well, we - * initialize it to NULL here for being able to check - * if we are in the first revolution of the loop. + * While "temp" is used for other things as well, we + * initialize it to NULL here for being able to check + * if we are in the first revolution of the loop. */ vm_object_t temp = NULL; while (object != NULL) { /* - * The cache holds a reference (uncounted) to - * the object; we must lock it before removing - * the object. + * The cache holds a reference (uncounted) to + * the object; we must lock it before removing + * the object. */ vm_object_cache_lock(); /* - * Lose the reference + * Lose the reference */ vm_object_lock(object); if (--(object->ref_count) != 0) { /* - * If this is a deallocation of a shadow - * reference (which it is unless it's the - * first time round) and this operation made - * us singly-shadowed, try to collapse us - * with our shadower. + * If this is a deallocation of a shadow + * reference (which it is unless it's the + * first time round) and this operation made + * us singly-shadowed, try to collapse us + * with our shadower. */ vm_object_unlock(object); if (temp != NULL && @@ -283,23 +283,22 @@ vm_object_deallocate(object) } /* - * If there are still references, then - * we are done. + * If there are still references, then + * we are done. */ vm_object_cache_unlock(); return; } /* - * See if this object can persist. If so, enter - * it in the cache, then deactivate all of its - * pages. + * See if this object can persist. If so, enter + * it in the cache, then deactivate all of its + * pages. */ - if (object->flags & OBJ_CANPERSIST) { TAILQ_INSERT_TAIL(&vm_object_cached_list, object, - cached_list); + cached_list); vm_object_cached++; vm_object_cache_unlock(); @@ -311,7 +310,7 @@ vm_object_deallocate(object) } /* - * Make sure no one can look us up now. + * Make sure no one can look us up now. */ vm_object_remove(object->pager); vm_object_cache_unlock(); @@ -325,10 +324,10 @@ vm_object_deallocate(object) /* - * vm_object_terminate actually destroys the specified object, freeing - * up all previously used resources. + * vm_object_terminate actually destroys the specified object, freeing + * up all previously used resources. * - * The object must be locked. + * The object must be locked. */ void vm_object_terminate(object) @@ -353,8 +352,8 @@ vm_object_terminate(object) } /* - * Detach the object from its shadow if we are the shadow's - * copy. + * Detach the object from its shadow if we are the shadow's + * copy. */ if ((shadow_object = object->shadow) != NULL) { vm_object_lock(shadow_object); @@ -411,21 +410,21 @@ vm_object_terminate(object) } /* - * vm_object_page_clean + * vm_object_page_clean * - * Clean all dirty pages in the specified range of object. - * If syncio is TRUE, page cleaning is done synchronously. - * If de_queue is TRUE, pages are removed from any paging queue - * they were on, otherwise they are left on whatever queue they - * were on before the cleaning operation began. + * Clean all dirty pages in the specified range of object. + * If syncio is TRUE, page cleaning is done synchronously. + * If de_queue is TRUE, pages are removed from any paging queue + * they were on, otherwise they are left on whatever queue they + * were on before the cleaning operation began. * - * Odd semantics: if start == end, we clean everything. + * Odd semantics: if start == end, we clean everything. * - * The object must be locked. + * The object must be locked. * - * Returns TRUE if all was well, FALSE if there was a pager error - * somewhere. We attempt to clean (and dequeue) all pages regardless - * of where an error occurs. + * Returns TRUE if all was well, FALSE if there was a pager error + * somewhere. We attempt to clean (and dequeue) all pages regardless + * of where an error occurs. */ boolean_t vm_object_page_clean(object, start, end, syncio, de_queue) @@ -454,8 +453,7 @@ vm_object_page_clean(object, start, end, syncio, de_queue) vm_object_unlock(object); pager = vm_pager_allocate(PG_DFLT, (caddr_t)0, - object->size, VM_PROT_ALL, - (vm_offset_t)0); + object->size, VM_PROT_ALL, (vm_offset_t)0); if (pager) vm_object_setpager(object, pager, 0, FALSE); vm_object_lock(object); @@ -555,12 +553,12 @@ again: } /* - * vm_object_deactivate_pages + * vm_object_deactivate_pages * - * Deactivate all pages in the specified object. (Keep its pages - * in memory even though it is no longer referenced.) + * Deactivate all pages in the specified object. (Keep its pages + * in memory even though it is no longer referenced.) * - * The object must be locked. + * The object must be locked. */ void vm_object_deactivate_pages(object) @@ -578,7 +576,7 @@ vm_object_deactivate_pages(object) } /* - * Trim the object cache to size. + * Trim the object cache to size. */ void vm_object_cache_trim() @@ -601,13 +599,13 @@ vm_object_cache_trim() } /* - * vm_object_pmap_copy: + * vm_object_pmap_copy: * - * Makes all physical pages in the specified - * object range copy-on-write. No writeable - * references to these pages should remain. + * Makes all physical pages in the specified + * object range copy-on-write. No writeable + * references to these pages should remain. * - * The object must *not* be locked. + * The object must *not* be locked. */ void vm_object_pmap_copy(object, start, end) @@ -631,12 +629,12 @@ vm_object_pmap_copy(object, start, end) } /* - * vm_object_pmap_remove: + * vm_object_pmap_remove: * - * Removes all physical pages in the specified - * object range from all physical maps. + * Removes all physical pages in the specified + * object range from all physical maps. * - * The object must *not* be locked. + * The object must *not* be locked. */ void vm_object_pmap_remove(object, start, end) @@ -657,15 +655,15 @@ vm_object_pmap_remove(object, start, end) } /* - * vm_object_copy: + * vm_object_copy: * - * Create a new object which is a copy of an existing - * object, and mark all of the pages in the existing - * object 'copy-on-write'. The new object has one reference. - * Returns the new object. + * Create a new object which is a copy of an existing + * object, and mark all of the pages in the existing + * object 'copy-on-write'. The new object has one reference. + * Returns the new object. * - * May defer the copy until later if the object is not backed - * up by a non-default pager. + * May defer the copy until later if the object is not backed + * up by a non-default pager. */ void vm_object_copy(src_object, src_offset, size, @@ -685,7 +683,7 @@ vm_object_copy(src_object, src_offset, size, if (src_object == NULL) { /* - * Nothing to copy + * Nothing to copy */ *dst_object = NULL; *dst_offset = 0; @@ -694,10 +692,10 @@ vm_object_copy(src_object, src_offset, size, } /* - * If the object's pager is null_pager or the - * default pager, we don't have to make a copy - * of it. Instead, we set the needs copy flag and - * make a shadow later. + * If the object's pager is null_pager or the + * default pager, we don't have to make a copy + * of it. Instead, we set the needs copy flag and + * make a shadow later. */ vm_object_lock(src_object); @@ -705,12 +703,12 @@ vm_object_copy(src_object, src_offset, size, (src_object->flags & OBJ_INTERNAL)) { /* - * Make another reference to the object + * Make another reference to the object */ src_object->ref_count++; /* - * Mark all of the pages copy-on-write. + * Mark all of the pages copy-on-write. */ for (p = src_object->memq.tqh_first; p; p = p->listq.tqe_next) if (src_offset <= p->offset && @@ -722,33 +720,33 @@ vm_object_copy(src_object, src_offset, size, *dst_offset = src_offset; /* - * Must make a shadow when write is desired + * Must make a shadow when write is desired */ *src_needs_copy = TRUE; return; } /* - * Try to collapse the object before copying it. + * Try to collapse the object before copying it. */ vm_object_collapse(src_object); /* - * If the object has a pager, the pager wants to - * see all of the changes. We need a copy-object - * for the changed pages. + * If the object has a pager, the pager wants to + * see all of the changes. We need a copy-object + * for the changed pages. * - * If there is a copy-object, and it is empty, - * no changes have been made to the object since the - * copy-object was made. We can use the same copy- - * object. + * If there is a copy-object, and it is empty, + * no changes have been made to the object since the + * copy-object was made. We can use the same copy- + * object. */ - Retry1: +Retry1: old_copy = src_object->copy; if (old_copy != NULL) { /* - * Try to get the locks (out of order) + * Try to get the locks (out of order) */ if (!vm_object_lock_try(old_copy)) { vm_object_unlock(src_object); @@ -761,8 +759,8 @@ vm_object_copy(src_object, src_offset, size, if (old_copy->resident_page_count == 0 && old_copy->pager == NULL) { /* - * Return another reference to - * the existing copy-object. + * Return another reference to + * the existing copy-object. */ old_copy->ref_count++; vm_object_unlock(old_copy); @@ -777,27 +775,27 @@ vm_object_copy(src_object, src_offset, size, vm_object_unlock(src_object); /* - * If the object has a pager, the pager wants - * to see all of the changes. We must make - * a copy-object and put the changed pages there. + * If the object has a pager, the pager wants + * to see all of the changes. We must make + * a copy-object and put the changed pages there. * - * The copy-object is always made large enough to - * completely shadow the original object, since - * it may have several users who want to shadow - * the original object at different points. + * The copy-object is always made large enough to + * completely shadow the original object, since + * it may have several users who want to shadow + * the original object at different points. */ new_copy = vm_object_allocate(src_object->size); - Retry2: +Retry2: vm_object_lock(src_object); /* - * Copy object may have changed while we were unlocked + * Copy object may have changed while we were unlocked */ old_copy = src_object->copy; if (old_copy != NULL) { /* - * Try to get the locks (out of order) + * Try to get the locks (out of order) */ if (!vm_object_lock_try(old_copy)) { vm_object_unlock(src_object); @@ -805,17 +803,17 @@ vm_object_copy(src_object, src_offset, size, } /* - * Consistency check + * Consistency check */ if (old_copy->shadow != src_object || old_copy->shadow_offset != (vm_offset_t) 0) panic("vm_object_copy: copy/shadow inconsistency"); /* - * Make the old copy-object shadow the new one. - * It will receive no more pages from the original - * object. Locking of new_copy not needed. We - * have the only pointer. + * Make the old copy-object shadow the new one. + * It will receive no more pages from the original + * object. Locking of new_copy not needed. We + * have the only pointer. */ src_object->ref_count--; /* remove ref. from old_copy */ vm_object_set_shadow(old_copy, new_copy); @@ -824,11 +822,11 @@ vm_object_copy(src_object, src_offset, size, vm_object_unlock(old_copy); /* done with old_copy */ } - new_start = (vm_offset_t) 0; /* always shadow original at 0 */ - new_end = (vm_offset_t) new_copy->size; /* for the whole object */ + new_start = (vm_offset_t)0; /* always shadow original at 0 */ + new_end = (vm_offset_t)new_copy->size; /* for the whole object */ /* - * Point the new copy at the existing object. + * Point the new copy at the existing object. */ vm_object_set_shadow(new_copy, src_object); @@ -837,8 +835,8 @@ vm_object_copy(src_object, src_offset, size, src_object->copy = new_copy; /* - * Mark all the affected pages of the existing object - * copy-on-write. + * Mark all the affected pages of the existing object + * copy-on-write. */ for (p = src_object->memq.tqh_first; p != NULL; p = p->listq.tqe_next) if ((new_start <= p->offset) && (p->offset < new_end)) @@ -852,16 +850,16 @@ vm_object_copy(src_object, src_offset, size, } /* - * vm_object_shadow: + * vm_object_shadow: * - * Create a new object which is backed by the - * specified existing object range. The source - * object reference is deallocated. + * Create a new object which is backed by the + * specified existing object range. The source + * object reference is deallocated. * - * The new object and offset into that object - * are returned in the source parameters. + * The new object and offset into that object + * are returned in the source parameters. * - * The old object should not be locked. + * The old object should not be locked. */ void vm_object_shadow(object, offset, length) @@ -875,37 +873,37 @@ vm_object_shadow(object, offset, length) source = *object; /* - * Allocate a new object with the given length + * Allocate a new object with the given length */ if ((result = vm_object_allocate(length)) == NULL) panic("vm_object_shadow: no object for shadowing"); /* - * The new object shadows the source object, adding - * a reference to it. Our caller changes his reference - * to point to the new object, removing a reference to - * the source object. Net result: no change of reference - * count. + * The new object shadows the source object, adding + * a reference to it. Our caller changes his reference + * to point to the new object, removing a reference to + * the source object. Net result: no change of reference + * count. */ vm_object_lock(source); vm_object_set_shadow(result, source); vm_object_unlock(source); /* - * Store the offset into the source object, - * and fix up the offset into the new object. + * Store the offset into the source object, + * and fix up the offset into the new object. */ result->shadow_offset = *offset; /* - * Return the new things + * Return the new things */ *offset = 0; *object = result; } /* - * Set the specified object's pager to the specified pager. + * Set the specified object's pager to the specified pager. */ void vm_object_setpager(object, pager, paging_offset, read_only) @@ -925,15 +923,15 @@ vm_object_setpager(object, pager, paging_offset, read_only) } /* - * vm_object_hash hashes the pager/id pair. + * vm_object_hash hashes the pager/id pair. */ #define vm_object_hash(pager) \ (((unsigned long)pager)%VM_OBJECT_HASH_COUNT) /* - * vm_object_lookup looks in the object cache for an object with the - * specified pager and paging id. + * vm_object_lookup looks in the object cache for an object with the + * specified pager and paging id. */ vm_object_t vm_object_lookup(pager) @@ -967,8 +965,8 @@ vm_object_lookup(pager) } /* - * vm_object_enter enters the specified object/pager/id into - * the hash table. + * vm_object_enter enters the specified object/pager/id into + * the hash table. */ void @@ -980,8 +978,8 @@ vm_object_enter(object, pager) register vm_object_hash_entry_t entry; /* - * We don't cache null objects, and we can't cache - * objects with the null pager. + * We don't cache null objects, and we can't cache + * objects with the null pager. */ if (object == NULL) @@ -1001,12 +999,12 @@ vm_object_enter(object, pager) } /* - * vm_object_remove: + * vm_object_remove: * - * Remove the pager from the hash table. - * Note: This assumes that the object cache - * is locked. XXX this should be fixed - * by reorganizing vm_object_deallocate. + * Remove the pager from the hash table. + * Note: This assumes that the object cache + * is locked. XXX this should be fixed + * by reorganizing vm_object_deallocate. */ void vm_object_remove(pager) @@ -1031,7 +1029,7 @@ vm_object_remove(pager) } /* - * vm_object_cache_clear removes all objects from the cache. + * vm_object_cache_clear removes all objects from the cache. * */ void @@ -1040,8 +1038,8 @@ vm_object_cache_clear() register vm_object_t object; /* - * Remove each object in the cache by scanning down the - * list of cached objects. + * Remove each object in the cache by scanning down the + * list of cached objects. */ vm_object_cache_lock(); while ((object = vm_object_cached_list.tqh_first) != NULL) { @@ -1063,10 +1061,10 @@ vm_object_cache_clear() } /* - * vm_object_remove_from_pager: + * vm_object_remove_from_pager: * - * Tell object's pager that it needn't back the page - * anymore. If the pager ends up empty, deallocate it. + * Tell object's pager that it needn't back the page + * anymore. If the pager ends up empty, deallocate it. */ int vm_object_remove_from_pager(object, from, to) @@ -1081,7 +1079,7 @@ vm_object_remove_from_pager(object, from, to) cnt = vm_pager_remove(pager, from, to); - /* If pager became empty, remove it. */ + /* If pager became empty, remove it. */ if (cnt > 0 && vm_pager_count(pager) == 0) { vm_pager_deallocate(pager); object->pager = NULL; @@ -1090,12 +1088,12 @@ vm_object_remove_from_pager(object, from, to) } /* - * vm_object_collapse_aux: + * vm_object_collapse_aux: * - * Internal function to vm_object_collapse called when - * it has been shown that a collapse operation is likely - * to succeed. We know that the backing object is only - * referenced by me and that paging is not in progress. + * Internal function to vm_object_collapse called when + * it has been shown that a collapse operation is likely + * to succeed. We know that the backing object is only + * referenced by me and that paging is not in progress. */ int vm_object_collapse_aux(object) @@ -1113,28 +1111,28 @@ vm_object_collapse_aux(object) #endif /* - * The algorithm used is roughly like this: - * (1) Trim a potential pager in the backing - * object so it'll only hold pages in reach. - * (2) Loop over all the resident pages in the - * shadow object and either remove them if - * they are shadowed or move them into the - * shadowing object. - * (3) Loop over the paged out pages in the - * shadow object. Start pageins on those - * that aren't shadowed, and just deallocate - * the others. In each iteration check if - * other users of these objects have caused - * pageins resulting in new resident pages. - * This can happen while we are waiting for - * a pagein of ours. If such resident pages - * turn up, restart from (2). + * The algorithm used is roughly like this: + * (1) Trim a potential pager in the backing + * object so it'll only hold pages in reach. + * (2) Loop over all the resident pages in the + * shadow object and either remove them if + * they are shadowed or move them into the + * shadowing object. + * (3) Loop over the paged out pages in the + * shadow object. Start pageins on those + * that aren't shadowed, and just deallocate + * the others. In each iteration check if + * other users of these objects have caused + * pageins resulting in new resident pages. + * This can happen while we are waiting for + * a pagein of ours. If such resident pages + * turn up, restart from (2). */ /* - * As a first measure we know we can discard - * everything that the shadowing object doesn't - * shadow. + * As a first measure we know we can discard + * everything that the shadowing object doesn't + * shadow. */ if (backing_object->pager != NULL) { if (backing_offset > 0) @@ -1146,28 +1144,28 @@ vm_object_collapse_aux(object) } /* - * This is the outer loop, iterating until all resident and - * paged out pages in the shadow object are drained. + * This is the outer loop, iterating until all resident and + * paged out pages in the shadow object are drained. */ paged_offset = 0; while (backing_object->memq.tqh_first != NULL || backing_object->pager != NULL) { /* - * First of all get rid of resident pages in the - * backing object. We can guarantee to remove - * every page thus we can write the while-test - * like this. + * First of all get rid of resident pages in the + * backing object. We can guarantee to remove + * every page thus we can write the while-test + * like this. */ while ((backing_page = backing_object->memq.tqh_first) != NULL) { /* - * If the page is outside the shadowing object's - * range or if the page is shadowed (either by a - * resident "non-fake" page or a paged out one) we - * can discard it right away. Otherwise we need - * to move the page to the shadowing object, - * perhaps waking up waiters for "fake" pages - * first. + * If the page is outside the shadowing object's + * range or if the page is shadowed (either by a + * resident "non-fake" page or a paged out one) we + * can discard it right away. Otherwise we need + * to move the page to the shadowing object, + * perhaps waking up waiters for "fake" pages + * first. */ if (backing_page->offset < backing_offset || (offset = backing_page->offset - backing_offset) >= @@ -1178,16 +1176,16 @@ vm_object_collapse_aux(object) vm_pager_has_page(object->pager, offset))) { /* - * Just discard the page, noone needs it. + * Just discard the page, noone needs it. */ vm_page_lock_queues(); vm_page_free(backing_page); vm_page_unlock_queues(); } else { /* - * If a "fake" page was found, someone may - * be waiting for it. Wake her up and - * then remove the page. + * If a "fake" page was found, someone may + * be waiting for it. Wake her up and + * then remove the page. */ if (page) { PAGE_WAKEUP(page); @@ -1197,14 +1195,14 @@ vm_object_collapse_aux(object) } /* - * If the backing page was ever paged out, - * it was due to it being dirty at one - * point. Unless we have no pager - * allocated to the front object (thus - * will move forward the shadow's one), - * mark it dirty again so it won't be - * thrown away without being paged out to - * the front pager. + * If the backing page was ever paged out, + * it was due to it being dirty at one + * point. Unless we have no pager + * allocated to the front object (thus + * will move forward the shadow's one), + * mark it dirty again so it won't be + * thrown away without being paged out to + * the front pager. */ if (object->pager != NULL && vm_object_remove_from_pager(backing_object, @@ -1212,22 +1210,22 @@ vm_object_collapse_aux(object) backing_page->offset + PAGE_SIZE)) backing_page->flags &= ~PG_CLEAN; - /* Move the page up front. */ + /* Move the page up front. */ vm_page_rename(backing_page, object, offset); } } /* - * If there isn't a pager in the shadow object, we're - * ready. Take the easy way out. + * If there isn't a pager in the shadow object, we're + * ready. Take the easy way out. */ if (backing_object->pager == NULL) break; /* - * If the shadowing object doesn't have a pager - * the easiest thing to do now is to just move the - * backing pager up front and everything is done. + * If the shadowing object doesn't have a pager + * the easiest thing to do now is to just move the + * backing pager up front and everything is done. */ if (object->pager == NULL) { object->pager = backing_object->pager; @@ -1238,29 +1236,29 @@ vm_object_collapse_aux(object) } /* - * What's left to do is to find all paged out - * pages in the backing pager and either discard - * or move it to the front object. We need to - * recheck the resident page set as a pagein might - * have given other threads the chance to, via - * readfaults, page in another page into the - * resident set. In this case the outer loop must - * get reentered. That is also the case if some other - * thread removes the front pager, a case that has - * been seen... + * What's left to do is to find all paged out + * pages in the backing pager and either discard + * or move it to the front object. We need to + * recheck the resident page set as a pagein might + * have given other threads the chance to, via + * readfaults, page in another page into the + * resident set. In this case the outer loop must + * get reentered. That is also the case if some other + * thread removes the front pager, a case that has + * been seen... */ while (backing_object->memq.tqh_first == NULL && backing_object->pager != NULL && object->pager != NULL && (paged_offset = vm_pager_next(backing_object->pager, paged_offset)) < backing_object->size) { /* - * If the shadowing object has this page, get - * rid of it from the backing pager. Trust - * the loop condition to get us out of here - * quickly if we remove the last paged out page. + * If the shadowing object has this page, get + * rid of it from the backing pager. Trust + * the loop condition to get us out of here + * quickly if we remove the last paged out page. * - * XXX Would clustering several pages at a time - * be a win in this situation? + * XXX Would clustering several pages at a time + * be a win in this situation? */ if (((page = vm_page_lookup(object, paged_offset - backing_offset)) == NULL || @@ -1268,9 +1266,9 @@ vm_object_collapse_aux(object) !vm_pager_has_page(object->pager, paged_offset - backing_offset)) { /* - * If a "fake" page was found, someone - * may be waiting for it. Wake her up - * and then remove the page. + * If a "fake" page was found, someone + * may be waiting for it. Wake her up + * and then remove the page. */ if (page) { PAGE_WAKEUP(page); @@ -1279,8 +1277,8 @@ vm_object_collapse_aux(object) vm_page_unlock_queues(); } /* - * Suck the page from the pager and give - * it to the shadowing object. + * Suck the page from the pager and give + * it to the shadowing object. */ #ifdef DEBUG if (vmdebug & VMDEBUG_COLLAPSE_PAGEIN) @@ -1289,9 +1287,9 @@ vm_object_collapse_aux(object) #endif /* - * First allocate a page and mark it - * busy so another thread won't try - * to start another pagein. + * First allocate a page and mark it + * busy so another thread won't try + * to start another pagein. */ for (;;) { backing_page = @@ -1304,12 +1302,12 @@ vm_object_collapse_aux(object) backing_page->flags |= PG_BUSY; /* - * Second, start paging it in. If this - * fails, what can we do but punt? - * Even though the shadowing object - * isn't exactly paging we say so in - * order to not get simultaneous - * cascaded collapses. + * Second, start paging it in. If this + * fails, what can we do but punt? + * Even though the shadowing object + * isn't exactly paging we say so in + * order to not get simultaneous + * cascaded collapses. */ object->paging_in_progress++; backing_object->paging_in_progress++; @@ -1324,11 +1322,11 @@ vm_object_collapse_aux(object) cnt.v_pgpgin++; /* - * A fault might have issued other - * pagein operations. We must wait for - * them to complete, then we get to - * wakeup potential other waiters as - * well. + * A fault might have issued other + * pagein operations. We must wait for + * them to complete, then we get to + * wakeup potential other waiters as + * well. */ while (backing_object->paging_in_progress != 1 || object->paging_in_progress != 1) { @@ -1348,11 +1346,11 @@ vm_object_collapse_aux(object) thread_wakeup(object); /* - * During the pagein vm_object_terminate - * might have slept on our front object in - * order to remove it. If this is the - * case, we might as well stop all the - * collapse work right here. + * During the pagein vm_object_terminate + * might have slept on our front object in + * order to remove it. If this is the + * case, we might as well stop all the + * collapse work right here. */ if (object->flags & OBJ_FADING) { PAGE_WAKEUP(backing_page); @@ -1360,26 +1358,26 @@ vm_object_collapse_aux(object) } /* - * Third, relookup in case pager changed - * page. Pager is responsible for - * disposition of old page if moved. + * Third, relookup in case pager changed + * page. Pager is responsible for + * disposition of old page if moved. */ backing_page = vm_page_lookup(backing_object, paged_offset); /* - * This page was once dirty, otherwise - * it hadn't been paged out in this - * shadow object. As we now remove the - * persistant store of the page, make - * sure it will be paged out in the - * front pager by dirtying it. + * This page was once dirty, otherwise + * it hadn't been paged out in this + * shadow object. As we now remove the + * persistant store of the page, make + * sure it will be paged out in the + * front pager by dirtying it. */ backing_page->flags &= ~(PG_FAKE|PG_CLEAN); /* - * Fourth, move it up front, and wake up - * potential waiters. + * Fourth, move it up front, and wake up + * potential waiters. */ vm_page_rename(backing_page, object, paged_offset - backing_offset); @@ -1393,10 +1391,10 @@ vm_object_collapse_aux(object) } /* - * I've seen this condition once in an out of VM situation. - * For the moment I don't know why it occurred, although I suspect - * vm_object_page_clean can create a pager even if it won't use - * it. + * I've seen this condition once in an out of VM situation. + * For the moment I don't know why it occurred, although I suspect + * vm_object_page_clean can create a pager even if it won't use + * it. */ if (backing_object->pager != NULL && vm_pager_count(backing_object->pager) == 0) { @@ -1410,9 +1408,9 @@ vm_object_collapse_aux(object) #endif /* - * Object now shadows whatever backing_object did. - * Note that the reference to backing_object->shadow - * moves from within backing_object to within object. + * Object now shadows whatever backing_object did. + * Note that the reference to backing_object->shadow + * moves from within backing_object to within object. */ if(backing_object->shadow) vm_object_lock(backing_object->shadow); @@ -1425,7 +1423,7 @@ vm_object_collapse_aux(object) if (object->shadow != NULL && object->shadow->copy != NULL) panic("vm_object_collapse_aux: we collapsed a copy-object!"); - /* Fast cleanup is the only thing left now. */ + /* Fast cleanup is the only thing left now. */ vm_object_unlock(backing_object); simple_lock(&vm_object_list_lock); @@ -1440,12 +1438,12 @@ vm_object_collapse_aux(object) } /* - * vm_object_bypass: + * vm_object_bypass: * - * Internal function to vm_object_collapse called when collapsing - * the object with its backing one is not allowed but there may - * be an opportunity to bypass the backing object and shadow the - * next object in the chain instead. + * Internal function to vm_object_collapse called when collapsing + * the object with its backing one is not allowed but there may + * be an opportunity to bypass the backing object and shadow the + * next object in the chain instead. */ int vm_object_bypass(object) @@ -1457,23 +1455,23 @@ vm_object_bypass(object) register vm_page_t p, pp; /* - * If all of the pages in the backing object are - * shadowed by the parent object, the parent - * object no longer has to shadow the backing - * object; it can shadow the next one in the - * chain. + * If all of the pages in the backing object are + * shadowed by the parent object, the parent + * object no longer has to shadow the backing + * object; it can shadow the next one in the + * chain. * - * The backing object must not be paged out - we'd - * have to check all of the paged-out pages, as - * well. + * The backing object must not be paged out - we'd + * have to check all of the paged-out pages, as + * well. */ if (backing_object->pager != NULL) return KERN_FAILURE; /* - * Should have a check for a 'small' number - * of pages here. + * Should have a check for a 'small' number + * of pages here. */ for (p = backing_object->memq.tqh_first; p != NULL; @@ -1481,29 +1479,29 @@ vm_object_bypass(object) new_offset = p->offset - backing_offset; /* - * If the parent has a page here, or if - * this page falls outside the parent, - * keep going. + * If the parent has a page here, or if + * this page falls outside the parent, + * keep going. * - * Otherwise, the backing_object must be - * left in the chain. + * Otherwise, the backing_object must be + * left in the chain. */ if (p->offset >= backing_offset && new_offset < object->size && ((pp = vm_page_lookup(object, new_offset)) == NULL || (pp->flags & PG_FAKE))) { /* - * Page still needed. Can't go any further. + * Page still needed. Can't go any further. */ return KERN_FAILURE; } } /* - * Make the parent shadow the next object - * in the chain. Deallocating backing_object - * will not remove it, since its reference - * count is at least 2. + * Make the parent shadow the next object + * in the chain. Deallocating backing_object + * will not remove it, since its reference + * count is at least 2. */ vm_object_lock(object->shadow); @@ -1517,17 +1515,17 @@ vm_object_bypass(object) object->shadow_offset += backing_object->shadow_offset; /* - * Backing object might have had a copy pointer - * to us. If it did, clear it. + * Backing object might have had a copy pointer + * to us. If it did, clear it. */ if (backing_object->copy == object) backing_object->copy = NULL; - /* Drop the reference count on backing_object. - * Since its ref_count was at least 2, it - * will not vanish; so we don't need to call - * vm_object_deallocate. + /* Drop the reference count on backing_object. + * Since its ref_count was at least 2, it + * will not vanish; so we don't need to call + * vm_object_deallocate. */ backing_object->ref_count--; vm_object_unlock(backing_object); @@ -1536,14 +1534,14 @@ vm_object_bypass(object) } /* - * vm_object_collapse: + * vm_object_collapse: * - * Collapse an object with the object backing it. - * Pages in the backing object are moved into the - * parent, and the backing object is deallocated. + * Collapse an object with the object backing it. + * Pages in the backing object are moved into the + * parent, and the backing object is deallocated. * - * Requires that the object be locked and the page - * queues be unlocked. + * Requires that the object be locked and the page + * queues be unlocked. * */ void @@ -1558,16 +1556,16 @@ vm_object_collapse(object) while (TRUE) { /* - * Verify that the conditions are right for collapse: + * Verify that the conditions are right for collapse: * - * The object exists and no pages in it are currently - * being paged out. + * The object exists and no pages in it are currently + * being paged out. */ if (object == NULL || object->paging_in_progress) return; /* - * There is a backing object, and + * There is a backing object, and */ if ((backing_object = object->shadow) == NULL) @@ -1575,11 +1573,11 @@ vm_object_collapse(object) vm_object_lock(backing_object); /* - * ... - * The backing object is not read_only, - * and no pages in the backing object are - * currently being paged out. - * The backing object is internal. + * ... + * The backing object is not read_only, + * and no pages in the backing object are + * currently being paged out. + * The backing object is internal. */ if ((backing_object->flags & OBJ_INTERNAL) == 0 || @@ -1589,14 +1587,14 @@ vm_object_collapse(object) } /* - * The backing object can't be a copy-object: - * the shadow_offset for the copy-object must stay - * as 0. Furthermore (for the 'we have all the - * pages' case), if we bypass backing_object and - * just shadow the next object in the chain, old - * pages from that object would then have to be copied - * BOTH into the (former) backing_object and into the - * parent object. + * The backing object can't be a copy-object: + * the shadow_offset for the copy-object must stay + * as 0. Furthermore (for the 'we have all the + * pages' case), if we bypass backing_object and + * just shadow the next object in the chain, old + * pages from that object would then have to be copied + * BOTH into the (former) backing_object and into the + * parent object. */ if (backing_object->shadow != NULL && backing_object->shadow->copy != NULL) { @@ -1605,9 +1603,9 @@ vm_object_collapse(object) } /* - * If there is exactly one reference to the backing - * object, we can collapse it into the parent, - * otherwise we might be able to bypass it completely. + * If there is exactly one reference to the backing + * object, we can collapse it into the parent, + * otherwise we might be able to bypass it completely. */ if (backing_object->ref_count == 1) { @@ -1622,18 +1620,18 @@ vm_object_collapse(object) } /* - * Try again with this object's new backing object. + * Try again with this object's new backing object. */ } } /* - * vm_object_page_remove: [internal] + * vm_object_page_remove: [internal] * - * Removes all physical pages in the specified - * object range from the object's list of pages. + * Removes all physical pages in the specified + * object range from the object's list of pages. * - * The object must be locked. + * The object must be locked. */ void vm_object_page_remove(object, start, end) @@ -1658,26 +1656,26 @@ vm_object_page_remove(object, start, end) } /* - * Routine: vm_object_coalesce - * Function: Coalesces two objects backing up adjoining - * regions of memory into a single object. + * Routine: vm_object_coalesce + * Function: Coalesces two objects backing up adjoining + * regions of memory into a single object. * - * returns TRUE if objects were combined. + * returns TRUE if objects were combined. * - * NOTE: Only works at the moment if the second object is NULL - - * if it's not, which object do we lock first? + * NOTE: Only works at the moment if the second object is NULL - + * if it's not, which object do we lock first? * - * Parameters: - * prev_object First object to coalesce - * prev_offset Offset into prev_object - * next_object Second object into coalesce - * next_offset Offset into next_object + * Parameters: + * prev_object First object to coalesce + * prev_offset Offset into prev_object + * next_object Second object into coalesce + * next_offset Offset into next_object * - * prev_size Size of reference to prev_object - * next_size Size of reference to next_object + * prev_size Size of reference to prev_object + * next_size Size of reference to next_object * - * Conditions: - * The object must *not* be locked. + * Conditions: + * The object must *not* be locked. */ boolean_t vm_object_coalesce(prev_object, next_object, @@ -1706,39 +1704,36 @@ vm_object_coalesce(prev_object, next_object, vm_object_lock(prev_object); /* - * Try to collapse the object first + * Try to collapse the object first */ vm_object_collapse(prev_object); /* - * Can't coalesce if: - * . more than one reference - * . paged out - * . shadows another object - * . has a copy elsewhere - * (any of which mean that the pages not mapped to - * prev_entry may be in use anyway) + * Can't coalesce if: + * . more than one reference + * . paged out + * . shadows another object + * . has a copy elsewhere + * (any of which mean that the pages not mapped to + * prev_entry may be in use anyway) */ - if (prev_object->ref_count > 1 || - prev_object->pager != NULL || - prev_object->shadow != NULL || - prev_object->copy != NULL) { + if (prev_object->ref_count > 1 || prev_object->pager != NULL || + prev_object->shadow != NULL || prev_object->copy != NULL) { vm_object_unlock(prev_object); return(FALSE); } /* - * Remove any pages that may still be in the object from - * a previous deallocation. + * Remove any pages that may still be in the object from + * a previous deallocation. */ - vm_object_page_remove(prev_object, - prev_offset + prev_size, - prev_offset + prev_size + next_size); + vm_object_page_remove(prev_object, prev_offset + prev_size, + prev_offset + prev_size + next_size); /* - * Extend the object if necessary. + * Extend the object if necessary. */ newsize = prev_offset + prev_size + next_size; if (newsize > prev_object->size) @@ -1749,7 +1744,7 @@ vm_object_coalesce(prev_object, next_object, } /* - * vm_object_print: [ debug ] + * vm_object_print: [ debug ] */ void vm_object_print(object, full) @@ -1775,14 +1770,15 @@ _vm_object_print(object, full, pr) return; iprintf(pr, "Object 0x%lx: size=0x%lx, res=%d, ref=%d, ", - (long) object, (long) object->size, + (long)object, (long)object->size, object->resident_page_count, object->ref_count); (*pr)("pager=0x%lx+0x%lx, shadow=(0x%lx)+0x%lx\n", - (long) object->pager, (long) object->paging_offset, - (long) object->shadow, (long) object->shadow_offset); + (long)object->pager, (long)object->paging_offset, + (long)object->shadow, (long)object->shadow_offset); (*pr)("shadowers=("); delim = ""; - for (o = object->shadowers.lh_first; o; o = o->shadowers_list.le_next) { + for (o = object->shadowers.lh_first; o; + o = o->shadowers_list.le_next) { (*pr)("%s0x%x", delim, o); delim = ", "; }; @@ -1815,13 +1811,13 @@ _vm_object_print(object, full, pr) } /* - * vm_object_set_shadow: + * vm_object_set_shadow: * - * Maintain the shadow graph so that back-link consistency is - * always kept. + * Maintain the shadow graph so that back-link consistency is + * always kept. * - * Assumes both objects as well as the old shadow to be locked - * (unless NULL of course). + * Assumes both objects as well as the old shadow to be locked + * (unless NULL of course). */ void vm_object_set_shadow(object, shadow) -- 2.20.1