From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:56627) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VswXs-0002NM-2f for qemu-devel@nongnu.org; Tue, 17 Dec 2013 10:26:58 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1VswXm-0000tT-40 for qemu-devel@nongnu.org; Tue, 17 Dec 2013 10:26:52 -0500 Received: from mx1.redhat.com ([209.132.183.28]:11551) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VswXl-0000t3-S6 for qemu-devel@nongnu.org; Tue, 17 Dec 2013 10:26:46 -0500 Received: from int-mx01.intmail.prod.int.phx2.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id rBHFQjSX022879 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Tue, 17 Dec 2013 10:26:45 -0500 From: Juan Quintela Date: Tue, 17 Dec 2013 16:26:00 +0100 Message-Id: <1387293974-24718-25-git-send-email-quintela@redhat.com> In-Reply-To: <1387293974-24718-1-git-send-email-quintela@redhat.com> References: <1387293974-24718-1-git-send-email-quintela@redhat.com> Subject: [Qemu-devel] [PATCH 24/38] memory: use find_next_bit() to find dirty bits List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org This operation is way faster than doing it bit by bit. Signed-off-by: Juan Quintela Reviewed-by: Eric Blake --- 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 c04a92a..b017c2e 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, -- 1.8.3.1