From: OHMURA Kei <ohmura.kei@lab.ntt.co.jp> To: Avi Kivity <avi@redhat.com>, "qemu-devel@nongnu.org" <qemu-devel@nongnu.org>, "kvm@vger.kernel.org" <kvm@vger.kernel.org> Cc: Anthony Liguori <anthony@codemonkey.ws>, drepper@redhat.com, mtosatti@redhat.com, Yoshiaki Tamura <tamura.yoshiaki@lab.ntt.co.jp>, ohmura.kei@lab.ntt.co.jp Subject: Re: [PATCH v2] qemu-kvm: Speed up of the dirty-bitmap-traveling Date: Mon, 15 Feb 2010 15:12:21 +0900 [thread overview] Message-ID: <4B78E5C5.80802@lab.ntt.co.jp> (raw) In-Reply-To: <4B77EDC2.7000401@redhat.com> 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 <ohmura.kei@lab.ntt.co.jp> --- 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
WARNING: multiple messages have this Message-ID (diff)
From: OHMURA Kei <ohmura.kei@lab.ntt.co.jp> To: Avi Kivity <avi@redhat.com>, "qemu-devel@nongnu.org" <qemu-devel@nongnu.org>, "kvm@vger.kernel.org" <kvm@vger.kernel.org> Cc: ohmura.kei@lab.ntt.co.jp, mtosatti@redhat.com, drepper@redhat.com, Yoshiaki Tamura <tamura.yoshiaki@lab.ntt.co.jp> Subject: [Qemu-devel] Re: [PATCH v2] qemu-kvm: Speed up of the dirty-bitmap-traveling Date: Mon, 15 Feb 2010 15:12:21 +0900 [thread overview] Message-ID: <4B78E5C5.80802@lab.ntt.co.jp> (raw) In-Reply-To: <4B77EDC2.7000401@redhat.com> 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 <ohmura.kei@lab.ntt.co.jp> --- 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
next prev parent reply other threads:[~2010-02-15 6:12 UTC|newest] Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top 2010-02-10 10:52 [PATCH v2] qemu-kvm: Speed up of the dirty-bitmap-traveling OHMURA Kei 2010-02-10 10:52 ` [Qemu-devel] " OHMURA Kei 2010-02-10 13:10 ` Ulrich Drepper 2010-02-10 13:10 ` [Qemu-devel] " Ulrich Drepper 2010-02-10 13:20 ` Avi Kivity 2010-02-10 13:20 ` [Qemu-devel] " Avi Kivity 2010-02-10 15:54 ` Anthony Liguori 2010-02-10 15:54 ` [Qemu-devel] " Anthony Liguori 2010-02-10 15:57 ` Avi Kivity 2010-02-10 15:57 ` [Qemu-devel] " Avi Kivity 2010-02-10 16:00 ` Alexander Graf 2010-02-10 16:00 ` Alexander Graf 2010-02-10 16:35 ` Anthony Liguori 2010-02-10 16:35 ` Anthony Liguori 2010-02-10 16:43 ` Alexander Graf 2010-02-10 16:43 ` Alexander Graf 2010-02-10 16:46 ` Avi Kivity 2010-02-10 16:46 ` Avi Kivity 2010-02-10 16:47 ` Alexander Graf 2010-02-10 16:47 ` Alexander Graf 2010-02-10 16:52 ` Avi Kivity 2010-02-10 16:52 ` Avi Kivity 2010-02-10 16:54 ` Alexander Graf 2010-02-10 16:54 ` Alexander Graf 2010-02-10 16:43 ` Avi Kivity 2010-02-10 16:43 ` Avi Kivity 2010-02-10 15:55 ` Anthony Liguori 2010-02-10 15:55 ` [Qemu-devel] " Anthony Liguori 2010-02-12 2:03 ` OHMURA Kei 2010-02-12 2:03 ` [Qemu-devel] " OHMURA Kei 2010-02-14 12:34 ` Avi Kivity 2010-02-14 12:34 ` [Qemu-devel] " Avi Kivity 2010-02-15 6:12 ` OHMURA Kei [this message] 2010-02-15 6:12 ` OHMURA Kei 2010-02-15 8:24 ` Alexander Graf 2010-02-15 8:24 ` Alexander Graf 2010-02-16 11:16 ` OHMURA Kei 2010-02-16 11:16 ` OHMURA Kei 2010-02-16 11:18 ` Alexander Graf 2010-02-16 11:18 ` Alexander Graf 2010-02-17 9:42 ` OHMURA Kei 2010-02-17 9:42 ` OHMURA Kei 2010-02-17 9:46 ` Alexander Graf 2010-02-17 9:46 ` Alexander Graf 2010-02-18 5:57 ` OHMURA Kei 2010-02-18 5:57 ` OHMURA Kei 2010-02-18 10:30 ` Alexander Graf 2010-02-18 10:30 ` Alexander Graf 2010-02-17 9:47 ` Avi Kivity 2010-02-17 9:47 ` Avi Kivity 2010-02-17 9:49 ` Alexander Graf 2010-02-17 9:49 ` Alexander Graf
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