From 1bafff0c7cb99972fd243464632eca0780c6a8f1 Mon Sep 17 00:00:00 2001 From: Juan Quintela Date: Wed, 9 Oct 2013 12:15:06 +0200 Subject: [PATCH] memory: use find_next_bit() to find dirty bits This operation is way faster than doing it bit by bit. Signed-off-by: Juan Quintela Reviewed-by: Eric Blake Reviewed-by: Orit Wasserman --- include/exec/memory-internal.h | 16 ++++++---------- 1 file changed, 6 insertions(+), 10 deletions(-) diff --git a/include/exec/memory-internal.h b/include/exec/memory-internal.h index c04a92a2d9..b017c2ec98 100644 --- a/include/exec/memory-internal.h +++ b/include/exec/memory-internal.h @@ -44,19 +44,15 @@ static inline bool cpu_physical_memory_get_dirty(ram_addr_t start, ram_addr_t length, unsigned client) { - ram_addr_t addr, end; + unsigned long end, page, next; assert(client < DIRTY_MEMORY_NUM); - end = TARGET_PAGE_ALIGN(start + length); - start &= TARGET_PAGE_MASK; - for (addr = start; addr < end; addr += TARGET_PAGE_SIZE) { - if (test_bit(addr >> TARGET_PAGE_BITS, - ram_list.dirty_memory[client])) { - return true; - } - } - return false; + end = TARGET_PAGE_ALIGN(start + length) >> TARGET_PAGE_BITS; + page = start >> TARGET_PAGE_BITS; + next = find_next_bit(ram_list.dirty_memory[client], end, page); + + return next < end; } static inline bool cpu_physical_memory_get_dirty_flag(ram_addr_t addr,