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exec: remove cur_map

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cur_map is not used anymore; instead, each AddressSpaceDispatch
has its own nodes/sections pair.  The priorities of the
MemoryListeners, and in the future RCU, guarantee that the
nodes/sections are not freed while they are still in use.

(In fact, next_map itself is not needed except to free the data on the
next update).

To avoid incorrect use, replace cur_map with a temporary copy that
is only valid while the topology is being updated.  If you use it,
the name prev_map makes it clear that you're doing something weird.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Paolo Bonzini 2013-05-29 12:30:26 +02:00
parent 0475d94fff
commit 6092666ebd
1 changed files with 7 additions and 5 deletions
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12
exec.c
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@ -122,7 +122,7 @@ typedef struct PhysPageMap {
MemoryRegionSection *sections; MemoryRegionSection *sections;
} PhysPageMap; } PhysPageMap;
static PhysPageMap cur_map; static PhysPageMap *prev_map;
static PhysPageMap next_map; static PhysPageMap next_map;
#define PHYS_MAP_NODE_NIL (((uint16_t)~0) >> 1) #define PHYS_MAP_NODE_NIL (((uint16_t)~0) >> 1)
@ -790,7 +790,7 @@ static void phys_section_destroy(MemoryRegion *mr)
} }
} }
static void phys_sections_clear(PhysPageMap *map) static void phys_sections_free(PhysPageMap *map)
{ {
while (map->sections_nb > 0) { while (map->sections_nb > 0) {
MemoryRegionSection *section = &map->sections[--map->sections_nb]; MemoryRegionSection *section = &map->sections[--map->sections_nb];
@ -798,6 +798,7 @@ static void phys_sections_clear(PhysPageMap *map)
} }
g_free(map->sections); g_free(map->sections);
g_free(map->nodes); g_free(map->nodes);
g_free(map);
} }
static void register_subpage(AddressSpaceDispatch *d, MemoryRegionSection *section) static void register_subpage(AddressSpaceDispatch *d, MemoryRegionSection *section)
@ -1731,6 +1732,9 @@ static void core_begin(MemoryListener *listener)
{ {
uint16_t n; uint16_t n;
prev_map = g_new(PhysPageMap, 1);
*prev_map = next_map;
memset(&next_map, 0, sizeof(next_map)); memset(&next_map, 0, sizeof(next_map));
n = dummy_section(&io_mem_unassigned); n = dummy_section(&io_mem_unassigned);
assert(n == PHYS_SECTION_UNASSIGNED); assert(n == PHYS_SECTION_UNASSIGNED);
@ -1747,9 +1751,7 @@ static void core_begin(MemoryListener *listener)
*/ */
static void core_commit(MemoryListener *listener) static void core_commit(MemoryListener *listener)
{ {
PhysPageMap info = cur_map; phys_sections_free(prev_map);
cur_map = next_map;
phys_sections_clear(&info);
} }
static void tcg_commit(MemoryListener *listener) static void tcg_commit(MemoryListener *listener)