diff options
| -rw-r--r-- | vm/vm_object.c | 165 | ||||
| -rw-r--r-- | vm/vm_object.h | 7 | ||||
| -rw-r--r-- | vm/vm_pageout.c | 7 | ||||
| -rw-r--r-- | vm/vm_resident.c | 4 |
4 files changed, 63 insertions, 120 deletions
diff --git a/vm/vm_object.c b/vm/vm_object.c index 18a909f8..9a019f6e 100644 --- a/vm/vm_object.c +++ b/vm/vm_object.c @@ -65,8 +65,6 @@ void memory_object_release( pager_request_t pager_request, ipc_port_t pager_name); /* forward */ -void vm_object_deactivate_pages(vm_object_t); - /* * Virtual memory objects maintain the actual data * associated with allocated virtual memory. A given @@ -167,8 +165,9 @@ vm_object_t kernel_object = &kernel_object_store; * * The kernel may choose to terminate objects from this * queue in order to reclaim storage. The current policy - * is to permit a fixed maximum number of unreferenced - * objects (vm_object_cached_max). + * is to let memory pressure dynamically adjust the number + * of unreferenced objects. The pageout daemon attempts to + * collect objects after removing pages from them. * * A simple lock (accessed by routines * vm_object_cache_{lock,lock_try,unlock}) governs the @@ -184,7 +183,6 @@ vm_object_t kernel_object = &kernel_object_store; */ queue_head_t vm_object_cached_list; int vm_object_cached_count; -int vm_object_cached_max = 4000; /* may be patched*/ decl_simple_lock_data(,vm_object_cached_lock_data) @@ -347,6 +345,33 @@ void vm_object_init(void) IKOT_PAGING_NAME); } +void vm_object_collect( + register vm_object_t object) +{ + vm_object_unlock(object); + + /* + * The cache lock must be acquired in the proper order. + */ + + vm_object_cache_lock(); + vm_object_lock(object); + + /* + * If the object was referenced while the lock was + * dropped, cancel the termination. + */ + + if (!vm_object_collectable(object)) { + vm_object_unlock(object); + vm_object_cache_unlock(); + return; + } + + queue_remove(&vm_object_cached_list, object, vm_object_t, cached_list); + vm_object_terminate(object); +} + /* * vm_object_reference: * @@ -407,103 +432,35 @@ void vm_object_deallocate( /* * See whether this object can persist. If so, enter - * it in the cache, then deactivate all of its - * pages. + * it in the cache. */ - if (object->can_persist) { - boolean_t overflow; - - /* - * Enter the object onto the queue - * of "cached" objects. Remember whether - * we've caused the queue to overflow, - * as a hint. - */ - + if (object->can_persist && (object->resident_page_count > 0)) { queue_enter(&vm_object_cached_list, object, vm_object_t, cached_list); - overflow = (++vm_object_cached_count > vm_object_cached_max); + vm_object_cached_count++; vm_object_cached_pages_update(object->resident_page_count); vm_object_cache_unlock(); - vm_object_deactivate_pages(object); vm_object_unlock(object); + return; + } - /* - * If we didn't overflow, or if the queue has - * been reduced back to below the specified - * minimum, then quit. - */ - if (!overflow) - return; - - while (TRUE) { - vm_object_cache_lock(); - if (vm_object_cached_count <= - vm_object_cached_max) { - vm_object_cache_unlock(); - return; - } - - /* - * If we must trim down the queue, take - * the first object, and proceed to - * terminate it instead of the original - * object. Have to wait for pager init. - * if it's in progress. - */ - object= (vm_object_t) - queue_first(&vm_object_cached_list); - vm_object_lock(object); - - if (!(object->pager_created && - !object->pager_initialized)) { - - /* - * Ok to terminate, hang on to lock. - */ - break; - } - - vm_object_assert_wait(object, - VM_OBJECT_EVENT_INITIALIZED, FALSE); - vm_object_unlock(object); - vm_object_cache_unlock(); - thread_block((void (*)()) 0); - - /* - * Continue loop to check if cache still - * needs to be trimmed. - */ - } + if (object->pager_created && + !object->pager_initialized) { /* - * Actually remove object from cache. + * Have to wait for initialization. + * Put reference back and retry + * when it's initialized. */ - queue_remove(&vm_object_cached_list, object, - vm_object_t, cached_list); - vm_object_cached_count--; - - assert(object->ref_count == 0); - } - else { - if (object->pager_created && - !object->pager_initialized) { - - /* - * Have to wait for initialization. - * Put reference back and retry - * when it's initialized. - */ - object->ref_count++; - vm_object_assert_wait(object, - VM_OBJECT_EVENT_INITIALIZED, FALSE); - vm_object_unlock(object); - vm_object_cache_unlock(); - thread_block((void (*)()) 0); - continue; - } + object->ref_count++; + vm_object_assert_wait(object, + VM_OBJECT_EVENT_INITIALIZED, FALSE); + vm_object_unlock(object); + vm_object_cache_unlock(); + thread_block((void (*)()) 0); + continue; } /* @@ -530,8 +487,6 @@ void vm_object_deallocate( } } -boolean_t vm_object_terminate_remove_all = FALSE; - /* * Routine: vm_object_terminate * Purpose: @@ -884,28 +839,6 @@ kern_return_t memory_object_destroy( } /* - * vm_object_deactivate_pages - * - * Deactivate all pages in the specified object. (Keep its pages - * in memory even though it is no longer referenced.) - * - * The object must be locked. - */ -void vm_object_deactivate_pages( - register vm_object_t object) -{ - register vm_page_t p; - - queue_iterate(&object->memq, p, vm_page_t, listq) { - vm_page_lock_queues(); - if (!p->busy) - vm_page_deactivate(p); - vm_page_unlock_queues(); - } -} - - -/* * Routine: vm_object_pmap_protect * * Purpose: @@ -2761,7 +2694,7 @@ void vm_object_page_remove( * It balances vm_object_lookup vs iteration. */ - if (atop(end - start) < (unsigned)object->resident_page_count/16) { + if (atop(end - start) < object->resident_page_count/16) { vm_object_page_remove_lookup++; for (; start < end; start += PAGE_SIZE) { @@ -2989,7 +2922,7 @@ void vm_object_print( iprintf("Object 0x%X: size=0x%X", (vm_offset_t) object, (vm_offset_t) object->size); - printf(", %d references, %d resident pages,", object->ref_count, + printf(", %d references, %lu resident pages,", object->ref_count, object->resident_page_count); printf(" %d absent pages,", object->absent_count); printf(" %d paging ops\n", object->paging_in_progress); diff --git a/vm/vm_object.h b/vm/vm_object.h index adeff657..95798790 100644 --- a/vm/vm_object.h +++ b/vm/vm_object.h @@ -72,7 +72,7 @@ struct vm_object { */ int ref_count; /* Number of references */ - int resident_page_count; + unsigned long resident_page_count; /* number of resident pages */ struct vm_object *copy; /* Object that should receive @@ -169,6 +169,7 @@ vm_object_t kernel_object; /* the single kernel object */ extern void vm_object_bootstrap(void); extern void vm_object_init(void); +extern void vm_object_collect(vm_object_t); extern void vm_object_terminate(vm_object_t); extern vm_object_t vm_object_allocate(vm_size_t); extern void vm_object_reference(vm_object_t); @@ -280,6 +281,10 @@ extern void vm_object_pager_wakeup(ipc_port_t pager); * Routines implemented as macros */ +#define vm_object_collectable(object) \ + (((object)->ref_count == 0) \ + && ((object)->resident_page_count == 0)) + #define vm_object_paging_begin(object) \ ((object)->paging_in_progress++) diff --git a/vm/vm_pageout.c b/vm/vm_pageout.c index 661675f0..eb75b975 100644 --- a/vm/vm_pageout.c +++ b/vm/vm_pageout.c @@ -750,7 +750,12 @@ void vm_pageout_scan() reclaim_page: vm_page_free(m); vm_page_unlock_queues(); - vm_object_unlock(object); + + if (vm_object_collectable(object)) + vm_object_collect(object); + else + vm_object_unlock(object); + continue; } diff --git a/vm/vm_resident.c b/vm/vm_resident.c index 7906b583..66ab51f0 100644 --- a/vm/vm_resident.c +++ b/vm/vm_resident.c @@ -523,7 +523,7 @@ void vm_page_insert( */ object->resident_page_count++; - assert(object->resident_page_count >= 0); + assert(object->resident_page_count != 0); if (object->can_persist && (object->ref_count == 0)) vm_object_cached_pages_update(1); @@ -630,7 +630,7 @@ void vm_page_replace( */ object->resident_page_count++; - assert(object->resident_page_count >= 0); + assert(object->resident_page_count != 0); if (object->can_persist && (object->ref_count == 0)) vm_object_cached_pages_update(1); |