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[Qemu-devel] Re: [PATCH v2] qemu-kvm: Speed up of the dirty-bitmap-trave
From: |
OHMURA Kei |
Subject: |
[Qemu-devel] Re: [PATCH v2] qemu-kvm: Speed up of the dirty-bitmap-traveling |
Date: |
Mon, 15 Feb 2010 15:12:21 +0900 |
User-agent: |
Thunderbird 2.0.0.23 (Windows/20090812) |
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 <address@hidden>
---
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
- Re: [Qemu-devel] Re: [PATCH v2] qemu-kvm: Speed up of the dirty-bitmap-traveling, (continued)
- Re: [Qemu-devel] Re: [PATCH v2] qemu-kvm: Speed up of the dirty-bitmap-traveling, Anthony Liguori, 2010/02/10
- Re: [Qemu-devel] Re: [PATCH v2] qemu-kvm: Speed up of the dirty-bitmap-traveling, Alexander Graf, 2010/02/10
- Re: [Qemu-devel] Re: [PATCH v2] qemu-kvm: Speed up of the dirty-bitmap-traveling, Avi Kivity, 2010/02/10
- Re: [Qemu-devel] Re: [PATCH v2] qemu-kvm: Speed up of the dirty-bitmap-traveling, Alexander Graf, 2010/02/10
- Re: [Qemu-devel] Re: [PATCH v2] qemu-kvm: Speed up of the dirty-bitmap-traveling, Avi Kivity, 2010/02/10
- Re: [Qemu-devel] Re: [PATCH v2] qemu-kvm: Speed up of the dirty-bitmap-traveling, Alexander Graf, 2010/02/10
- Re: [Qemu-devel] Re: [PATCH v2] qemu-kvm: Speed up of the dirty-bitmap-traveling, Avi Kivity, 2010/02/10
[Qemu-devel] Re: [PATCH v2] qemu-kvm: Speed up of the dirty-bitmap-traveling, Anthony Liguori, 2010/02/10
- [Qemu-devel] Re: [PATCH v2] qemu-kvm: Speed up of the dirty-bitmap-traveling, OHMURA Kei, 2010/02/11
- [Qemu-devel] Re: [PATCH v2] qemu-kvm: Speed up of the dirty-bitmap-traveling, Avi Kivity, 2010/02/14
- [Qemu-devel] Re: [PATCH v2] qemu-kvm: Speed up of the dirty-bitmap-traveling,
OHMURA Kei <=
- Re: [Qemu-devel] Re: [PATCH v2] qemu-kvm: Speed up of the dirty-bitmap-traveling, Alexander Graf, 2010/02/15
- Re: [Qemu-devel] Re: [PATCH v2] qemu-kvm: Speed up of the dirty-bitmap-traveling, OHMURA Kei, 2010/02/16
- Re: [Qemu-devel] Re: [PATCH v2] qemu-kvm: Speed up of the dirty-bitmap-traveling, Alexander Graf, 2010/02/16
- Re: [Qemu-devel] Re: [PATCH v2] qemu-kvm: Speed up of the dirty-bitmap-traveling, OHMURA Kei, 2010/02/17
- Re: [Qemu-devel] Re: [PATCH v2] qemu-kvm: Speed up of the dirty-bitmap-traveling, Alexander Graf, 2010/02/17
- Re: [Qemu-devel] Re: [PATCH v2] qemu-kvm: Speed up of the dirty-bitmap-traveling, OHMURA Kei, 2010/02/18
- Re: [Qemu-devel] Re: [PATCH v2] qemu-kvm: Speed up of the dirty-bitmap-traveling, Alexander Graf, 2010/02/18
Re: [Qemu-devel] Re: [PATCH v2] qemu-kvm: Speed up of the dirty-bitmap-traveling, Avi Kivity, 2010/02/17
Re: [Qemu-devel] Re: [PATCH v2] qemu-kvm: Speed up of the dirty-bitmap-traveling, Alexander Graf, 2010/02/17
[Qemu-devel] Re: [PATCH v2] qemu-kvm: Speed up of the dirty-bitmap-traveling, Ulrich Drepper, 2010/02/10