From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1NguBx-0008Qb-0B for qemu-devel@nongnu.org; Mon, 15 Feb 2010 01:12:21 -0500 Received: from [199.232.76.173] (port=56947 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1NguBw-0008QE-FR for qemu-devel@nongnu.org; Mon, 15 Feb 2010 01:12:20 -0500 Received: from Debian-exim by monty-python.gnu.org with spam-scanned (Exim 4.60) (envelope-from ) id 1NguBv-0002m3-76 for qemu-devel@nongnu.org; Mon, 15 Feb 2010 01:12:20 -0500 Received: from tama500.ecl.ntt.co.jp ([129.60.39.148]:39050) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1NguBu-0002lr-JH for qemu-devel@nongnu.org; Mon, 15 Feb 2010 01:12:19 -0500 Message-ID: <4B78E5C5.80802@lab.ntt.co.jp> Date: Mon, 15 Feb 2010 15:12:21 +0900 From: OHMURA Kei MIME-Version: 1.0 References: <4B728FF9.6010707@lab.ntt.co.jp> <4B72B28E.6010801@redhat.com> <4B72D706.3070602@codemonkey.ws> <4B74B70A.4030805@lab.ntt.co.jp> <4B77EDC2.7000401@redhat.com> In-Reply-To: <4B77EDC2.7000401@redhat.com> Content-Type: text/plain; charset=ISO-2022-JP Content-Transfer-Encoding: 7bit Subject: [Qemu-devel] Re: [PATCH v2] qemu-kvm: Speed up of the dirty-bitmap-traveling List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Avi Kivity , "qemu-devel@nongnu.org" , "kvm@vger.kernel.org" Cc: ohmura.kei@lab.ntt.co.jp, mtosatti@redhat.com, drepper@redhat.com, Yoshiaki Tamura dirty-bitmap-traveling is carried out by byte size in qemu-kvm.c. But We think that dirty-bitmap-traveling by long size is faster than by byte size especially when most of memory is not dirty. Signed-off-by: OHMURA Kei --- bswap.h | 2 ++ qemu-kvm.c | 31 ++++++++++++++++--------------- 2 files changed, 18 insertions(+), 15 deletions(-) diff --git a/bswap.h b/bswap.h index 4558704..1f87e6d 100644 --- a/bswap.h +++ b/bswap.h @@ -205,8 +205,10 @@ static inline void cpu_to_be32wu(uint32_t *p, uint32_t v) #ifdef HOST_WORDS_BIGENDIAN #define cpu_to_32wu cpu_to_be32wu +#define leul_to_cpu(v) le ## HOST_LONG_BITS ## _to_cpu(v) #else #define cpu_to_32wu cpu_to_le32wu +#define leul_to_cpu(v) (v) #endif #undef le_bswap diff --git a/qemu-kvm.c b/qemu-kvm.c index a305907..6952aa5 100644 --- a/qemu-kvm.c +++ b/qemu-kvm.c @@ -2434,31 +2434,32 @@ int kvm_physical_memory_set_dirty_tracking(int enable) /* get kvm's dirty pages bitmap and update qemu's */ static int kvm_get_dirty_pages_log_range(unsigned long start_addr, - unsigned char *bitmap, + unsigned long *bitmap, unsigned long offset, unsigned long mem_size) { - unsigned int i, j, n = 0; - unsigned char c; - unsigned long page_number, addr, addr1; + unsigned int i, j; + unsigned long page_number, addr, addr1, c; ram_addr_t ram_addr; - unsigned int len = ((mem_size / TARGET_PAGE_SIZE) + 7) / 8; + unsigned int len = ((mem_size / TARGET_PAGE_SIZE) + HOST_LONG_BITS - 1) / + HOST_LONG_BITS; /* * bitmap-traveling is faster than memory-traveling (for addr...) * especially when most of the memory is not dirty. */ for (i = 0; i < len; i++) { - c = bitmap[i]; - while (c > 0) { - j = ffsl(c) - 1; - c &= ~(1u << j); - page_number = i * 8 + j; - addr1 = page_number * TARGET_PAGE_SIZE; - addr = offset + addr1; - ram_addr = cpu_get_physical_page_desc(addr); - cpu_physical_memory_set_dirty(ram_addr); - n++; + if (bitmap[i] != 0) { + c = leul_to_cpu(bitmap[i]); + do { + j = ffsl(c) - 1; + c &= ~(1ul << j); + page_number = i * HOST_LONG_BITS + j; + addr1 = page_number * TARGET_PAGE_SIZE; + addr = offset + addr1; + ram_addr = cpu_get_physical_page_desc(addr); + cpu_physical_memory_set_dirty(ram_addr); + } while (c != 0); } } return 0; -- 1.6.3.3