diff options
| -rw-r--r-- | migration/ram.c | 44 |
1 files changed, 27 insertions, 17 deletions
diff --git a/migration/ram.c b/migration/ram.c index 2d1d0b99e4..a25bcc7db1 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -219,7 +219,6 @@ static RAMBlock *last_seen_block; /* This is the last block from where we have sent data */ static RAMBlock *last_sent_block; static ram_addr_t last_offset; -static unsigned long *migration_bitmap; static QemuMutex migration_bitmap_mutex; static uint64_t migration_dirty_pages; static uint32_t last_version; @@ -236,6 +235,11 @@ struct PageSearchStatus { }; typedef struct PageSearchStatus PageSearchStatus; +static struct BitmapRcu { + struct rcu_head rcu; + unsigned long *bmap; +} *migration_bitmap_rcu; + struct CompressParam { bool start; bool done; @@ -540,7 +544,7 @@ ram_addr_t migration_bitmap_find_and_reset_dirty(RAMBlock *rb, unsigned long next; - bitmap = atomic_rcu_read(&migration_bitmap); + bitmap = atomic_rcu_read(&migration_bitmap_rcu)->bmap; if (ram_bulk_stage && nr > base) { next = nr + 1; } else { @@ -558,7 +562,7 @@ ram_addr_t migration_bitmap_find_and_reset_dirty(RAMBlock *rb, static void migration_bitmap_sync_range(ram_addr_t start, ram_addr_t length) { unsigned long *bitmap; - bitmap = atomic_rcu_read(&migration_bitmap); + bitmap = atomic_rcu_read(&migration_bitmap_rcu)->bmap; migration_dirty_pages += cpu_physical_memory_sync_dirty_bitmap(bitmap, start, length); } @@ -1090,17 +1094,22 @@ void free_xbzrle_decoded_buf(void) xbzrle_decoded_buf = NULL; } +static void migration_bitmap_free(struct BitmapRcu *bmap) +{ + g_free(bmap->bmap); + g_free(bmap); +} + static void migration_end(void) { /* caller have hold iothread lock or is in a bh, so there is * no writing race against this migration_bitmap */ - unsigned long *bitmap = migration_bitmap; - atomic_rcu_set(&migration_bitmap, NULL); + struct BitmapRcu *bitmap = migration_bitmap_rcu; + atomic_rcu_set(&migration_bitmap_rcu, NULL); if (bitmap) { memory_global_dirty_log_stop(); - synchronize_rcu(); - g_free(bitmap); + call_rcu(bitmap, migration_bitmap_free, rcu); } XBZRLE_cache_lock(); @@ -1136,9 +1145,10 @@ void migration_bitmap_extend(ram_addr_t old, ram_addr_t new) /* called in qemu main thread, so there is * no writing race against this migration_bitmap */ - if (migration_bitmap) { - unsigned long *old_bitmap = migration_bitmap, *bitmap; - bitmap = bitmap_new(new); + if (migration_bitmap_rcu) { + struct BitmapRcu *old_bitmap = migration_bitmap_rcu, *bitmap; + bitmap = g_new(struct BitmapRcu, 1); + bitmap->bmap = bitmap_new(new); /* prevent migration_bitmap content from being set bit * by migration_bitmap_sync_range() at the same time. @@ -1146,13 +1156,12 @@ void migration_bitmap_extend(ram_addr_t old, ram_addr_t new) * at the same time. */ qemu_mutex_lock(&migration_bitmap_mutex); - bitmap_copy(bitmap, old_bitmap, old); - bitmap_set(bitmap, old, new - old); - atomic_rcu_set(&migration_bitmap, bitmap); + bitmap_copy(bitmap->bmap, old_bitmap->bmap, old); + bitmap_set(bitmap->bmap, old, new - old); + atomic_rcu_set(&migration_bitmap_rcu, bitmap); qemu_mutex_unlock(&migration_bitmap_mutex); migration_dirty_pages += new - old; - synchronize_rcu(); - g_free(old_bitmap); + call_rcu(old_bitmap, migration_bitmap_free, rcu); } } @@ -1210,8 +1219,9 @@ static int ram_save_setup(QEMUFile *f, void *opaque) reset_ram_globals(); ram_bitmap_pages = last_ram_offset() >> TARGET_PAGE_BITS; - migration_bitmap = bitmap_new(ram_bitmap_pages); - bitmap_set(migration_bitmap, 0, ram_bitmap_pages); + migration_bitmap_rcu = g_new(struct BitmapRcu, 1); + migration_bitmap_rcu->bmap = bitmap_new(ram_bitmap_pages); + bitmap_set(migration_bitmap_rcu->bmap, 0, ram_bitmap_pages); /* * Count the total number of pages used by ram blocks not including any |