diff options
Diffstat (limited to 'accel')
| -rw-r--r-- | accel/tcg/translate-all.c | 24 |
1 files changed, 14 insertions, 10 deletions
diff --git a/accel/tcg/translate-all.c b/accel/tcg/translate-all.c index 52e62125ed..52273e5846 100644 --- a/accel/tcg/translate-all.c +++ b/accel/tcg/translate-all.c @@ -469,20 +469,12 @@ static void page_init(void) #endif } -/* If alloc=1: - * Called with tb_lock held for system emulation. - * Called with mmap_lock held for user-mode emulation. - */ static PageDesc *page_find_alloc(tb_page_addr_t index, int alloc) { PageDesc *pd; void **lp; int i; - if (alloc) { - assert_memory_lock(); - } - /* Level 1. Always allocated. */ lp = l1_map + ((index >> v_l1_shift) & (v_l1_size - 1)); @@ -491,11 +483,17 @@ static PageDesc *page_find_alloc(tb_page_addr_t index, int alloc) void **p = atomic_rcu_read(lp); if (p == NULL) { + void *existing; + if (!alloc) { return NULL; } p = g_new0(void *, V_L2_SIZE); - atomic_rcu_set(lp, p); + existing = atomic_cmpxchg(lp, NULL, p); + if (unlikely(existing)) { + g_free(p); + p = existing; + } } lp = p + ((index >> (i * V_L2_BITS)) & (V_L2_SIZE - 1)); @@ -503,11 +501,17 @@ static PageDesc *page_find_alloc(tb_page_addr_t index, int alloc) pd = atomic_rcu_read(lp); if (pd == NULL) { + void *existing; + if (!alloc) { return NULL; } pd = g_new0(PageDesc, V_L2_SIZE); - atomic_rcu_set(lp, pd); + existing = atomic_cmpxchg(lp, NULL, pd); + if (unlikely(existing)) { + g_free(pd); + pd = existing; + } } return pd + (index & (V_L2_SIZE - 1)); |