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[Qemu-devel] [PATCH v2] qemu-kvm: Speed up of the dirty-bitmap-traveling
From: |
OHMURA Kei |
Subject: |
[Qemu-devel] [PATCH v2] qemu-kvm: Speed up of the dirty-bitmap-traveling |
Date: |
Wed, 10 Feb 2010 19:52:41 +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 | 1 -
qemu-kvm.c | 30 ++++++++++++++++--------------
2 files changed, 16 insertions(+), 15 deletions(-)
diff --git a/bswap.h b/bswap.h
index 4558704..d896f01 100644
--- a/bswap.h
+++ b/bswap.h
@@ -209,7 +209,6 @@ static inline void cpu_to_be32wu(uint32_t *p, uint32_t v)
#define cpu_to_32wu cpu_to_le32wu
#endif
-#undef le_bswap
#undef be_bswap
#undef le_bswaps
#undef be_bswaps
diff --git a/qemu-kvm.c b/qemu-kvm.c
index a305907..ea07912 100644
--- a/qemu-kvm.c
+++ b/qemu-kvm.c
@@ -2438,27 +2438,29 @@ static int kvm_get_dirty_pages_log_range(unsigned long
start_addr,
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;
+ unsigned long *bitmap_ul = (unsigned long *)bitmap;
/*
* 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_ul[i] != 0) {
+ c = le_bswap(bitmap_ul[i], HOST_LONG_BITS);
+ while (c > 0) {
+ 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);
+ }
}
}
return 0;
--
1.6.3.3
- [Qemu-devel] [PATCH v2] qemu-kvm: Speed up of the dirty-bitmap-traveling,
OHMURA Kei <=
- [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, 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, 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