diff options
| -rw-r--r-- | device/ds_routines.c | 2 | ||||
| -rw-r--r-- | kern/thread.c | 6 | ||||
| -rw-r--r-- | kern/thread.h | 5 | ||||
| -rw-r--r-- | vm/vm_map.c | 63 | ||||
| -rw-r--r-- | vm/vm_map.h | 8 | ||||
| -rw-r--r-- | vm/vm_pageout.c | 2 |
6 files changed, 49 insertions, 37 deletions
diff --git a/device/ds_routines.c b/device/ds_routines.c index 445e7ae1..1fabec3c 100644 --- a/device/ds_routines.c +++ b/device/ds_routines.c @@ -1512,7 +1512,7 @@ void io_done_thread(void) /* * Set thread privileges and highest priority. */ - current_thread()->vm_privilege = TRUE; + current_thread()->vm_privilege = 1; stack_privilege(current_thread()); thread_set_own_priority(0); diff --git a/kern/thread.c b/kern/thread.c index 7db1f3d2..0ac7c535 100644 --- a/kern/thread.c +++ b/kern/thread.c @@ -342,7 +342,7 @@ void thread_init(void) /* thread_template.sched_stamp (later) */ thread_template.recover = (vm_offset_t) 0; - thread_template.vm_privilege = FALSE; + thread_template.vm_privilege = 0; thread_template.user_stop_count = 1; @@ -2233,11 +2233,11 @@ thread_wire( thread_lock(thread); if (wired) { - thread->vm_privilege = TRUE; + thread->vm_privilege = 1; stack_privilege(thread); } else { - thread->vm_privilege = FALSE; + thread->vm_privilege = 0; /*XXX stack_unprivilege(thread); */ thread->stack_privilege = 0; } diff --git a/kern/thread.h b/kern/thread.h index 7106fd2d..f0ed71a8 100644 --- a/kern/thread.h +++ b/kern/thread.h @@ -77,7 +77,6 @@ struct thread { struct { unsigned state:16; unsigned wake_active:1; - unsigned vm_privilege:1; unsigned active:1; }; event_t event_key; @@ -146,8 +145,8 @@ struct thread { /* VM global variables */ vm_offset_t recover; /* page fault recovery (copyin/out) */ - /* Defined above */ - /* boolean_t vm_privilege; Can use reserved memory? */ + unsigned int vm_privilege; /* Can use reserved memory? + Implemented as a counter */ /* User-visible scheduling state */ int user_stop_count; /* outstanding stops */ diff --git a/vm/vm_map.c b/vm/vm_map.c index f52e7c76..b1c1b4e0 100644 --- a/vm/vm_map.c +++ b/vm/vm_map.c @@ -222,29 +222,15 @@ vm_map_t vm_map_create( return(result); } -/* - * vm_map_entry_create: [ internal use only ] - * - * Allocates a VM map entry for insertion in the - * given map (or map copy). No fields are filled. - */ -#define vm_map_entry_create(map) \ - _vm_map_entry_create(&(map)->hdr) - -#define vm_map_copy_entry_create(copy) \ - _vm_map_entry_create(&(copy)->cpy_hdr) - -vm_map_entry_t _vm_map_entry_create(map_header) - const struct vm_map_header *map_header; +void vm_map_lock(struct vm_map *map) { - vm_map_entry_t entry; - boolean_t vm_privilege; + lock_write(&map->lock); /* - * XXX Map entry creation may occur while a map is locked, + * XXX Memory allocation may occur while a map is locked, * for example when clipping entries. If the system is running - * low on memory, allocating an entry may block until pages - * are available. But if a map used by the default pager is + * low on memory, allocating may block until pages are + * available. But if a map used by the default pager is * kept locked, a deadlock occurs. * * This workaround temporarily elevates the current thread @@ -252,19 +238,50 @@ vm_map_entry_t _vm_map_entry_create(map_header) * so regardless of the map for convenience, and because it's * currently impossible to predict which map the default pager * may depend on. + * + * This workaround isn't reliable, and only makes exhaustion + * less likely. In particular pageout may cause lots of data + * to be passed between the kernel and the pagers, often + * in the form of large copy maps. Making the minimum + * number of pages depend on the total number of pages + * should make exhaustion even less likely. */ if (current_thread()) { - vm_privilege = current_thread()->vm_privilege; - current_thread()->vm_privilege = TRUE; + current_thread()->vm_privilege++; + assert(current_thread()->vm_privilege != 0); } - entry = (vm_map_entry_t) kmem_cache_alloc(&vm_map_entry_cache); + map->timestamp++; +} +void vm_map_unlock(struct vm_map *map) +{ if (current_thread()) { - current_thread()->vm_privilege = vm_privilege; + current_thread()->vm_privilege--; } + lock_write_done(&map->lock); +} + +/* + * vm_map_entry_create: [ internal use only ] + * + * Allocates a VM map entry for insertion in the + * given map (or map copy). No fields are filled. + */ +#define vm_map_entry_create(map) \ + _vm_map_entry_create(&(map)->hdr) + +#define vm_map_copy_entry_create(copy) \ + _vm_map_entry_create(&(copy)->cpy_hdr) + +vm_map_entry_t _vm_map_entry_create(map_header) + const struct vm_map_header *map_header; +{ + vm_map_entry_t entry; + + entry = (vm_map_entry_t) kmem_cache_alloc(&vm_map_entry_cache); if (entry == VM_MAP_ENTRY_NULL) panic("vm_map_entry_create"); diff --git a/vm/vm_map.h b/vm/vm_map.h index dad07139..537c36ef 100644 --- a/vm/vm_map.h +++ b/vm/vm_map.h @@ -352,13 +352,9 @@ MACRO_BEGIN \ (map)->timestamp = 0; \ MACRO_END -#define vm_map_lock(map) \ -MACRO_BEGIN \ - lock_write(&(map)->lock); \ - (map)->timestamp++; \ -MACRO_END +void vm_map_lock(struct vm_map *map); +void vm_map_unlock(struct vm_map *map); -#define vm_map_unlock(map) lock_write_done(&(map)->lock) #define vm_map_lock_read(map) lock_read(&(map)->lock) #define vm_map_unlock_read(map) lock_read_done(&(map)->lock) #define vm_map_lock_write_to_read(map) \ diff --git a/vm/vm_pageout.c b/vm/vm_pageout.c index f420804b..e0bd9880 100644 --- a/vm/vm_pageout.c +++ b/vm/vm_pageout.c @@ -918,7 +918,7 @@ void vm_pageout(void) { unsigned long free_after_reserve; - current_thread()->vm_privilege = TRUE; + current_thread()->vm_privilege = 1; stack_privilege(current_thread()); thread_set_own_priority(0); |