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| author | Stefan Hajnoczi <stefanha@redhat.com> | 2014-12-02 11:23:18 +0000 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2015-06-05 17:10:00 +0200 |
| commit | 03eebc9e3246b9b3f5925aa41f7dfd7c1e467875 (patch) | |
| tree | 74641e34056f1169770c48aa604477315210d6be /include/exec | |
| parent | 20015f72bda7d2f356c43580a5542a659afedf83 (diff) | |
| download | qemu-03eebc9e3246b9b3f5925aa41f7dfd7c1e467875.zip qemu-03eebc9e3246b9b3f5925aa41f7dfd7c1e467875.tar.gz qemu-03eebc9e3246b9b3f5925aa41f7dfd7c1e467875.tar.bz2 | |
memory: replace cpu_physical_memory_reset_dirty() with test-and-clear
The cpu_physical_memory_reset_dirty() function is sometimes used
together with cpu_physical_memory_get_dirty(). This is not atomic since
two separate accesses to the dirty memory bitmap are made.
Turn cpu_physical_memory_reset_dirty() and
cpu_physical_memory_clear_dirty_range_type() into the atomic
cpu_physical_memory_test_and_clear_dirty().
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <1417519399-3166-6-git-send-email-stefanha@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'include/exec')
| -rw-r--r-- | include/exec/ram_addr.h | 33 |
1 files changed, 10 insertions, 23 deletions
diff --git a/include/exec/ram_addr.h b/include/exec/ram_addr.h index 63db371..a2beea7 100644 --- a/include/exec/ram_addr.h +++ b/include/exec/ram_addr.h @@ -194,30 +194,19 @@ static inline void cpu_physical_memory_set_dirty_lebitmap(unsigned long *bitmap, } #endif /* not _WIN32 */ -static inline void cpu_physical_memory_clear_dirty_range_type(ram_addr_t start, - ram_addr_t length, - unsigned client) -{ - unsigned long end, page; - - assert(client < DIRTY_MEMORY_NUM); - end = TARGET_PAGE_ALIGN(start + length) >> TARGET_PAGE_BITS; - page = start >> TARGET_PAGE_BITS; - bitmap_clear(ram_list.dirty_memory[client], page, end - page); -} +bool cpu_physical_memory_test_and_clear_dirty(ram_addr_t start, + ram_addr_t length, + unsigned client); static inline void cpu_physical_memory_clear_dirty_range(ram_addr_t start, ram_addr_t length) { - cpu_physical_memory_clear_dirty_range_type(start, length, DIRTY_MEMORY_MIGRATION); - cpu_physical_memory_clear_dirty_range_type(start, length, DIRTY_MEMORY_VGA); - cpu_physical_memory_clear_dirty_range_type(start, length, DIRTY_MEMORY_CODE); + cpu_physical_memory_test_and_clear_dirty(start, length, DIRTY_MEMORY_MIGRATION); + cpu_physical_memory_test_and_clear_dirty(start, length, DIRTY_MEMORY_VGA); + cpu_physical_memory_test_and_clear_dirty(start, length, DIRTY_MEMORY_CODE); } -void cpu_physical_memory_reset_dirty(ram_addr_t start, ram_addr_t length, - unsigned client); - static inline uint64_t cpu_physical_memory_sync_dirty_bitmap(unsigned long *dest, ram_addr_t start, @@ -245,16 +234,14 @@ uint64_t cpu_physical_memory_sync_dirty_bitmap(unsigned long *dest, } } else { for (addr = 0; addr < length; addr += TARGET_PAGE_SIZE) { - if (cpu_physical_memory_get_dirty(start + addr, - TARGET_PAGE_SIZE, - DIRTY_MEMORY_MIGRATION)) { + if (cpu_physical_memory_test_and_clear_dirty( + start + addr, + TARGET_PAGE_SIZE, + DIRTY_MEMORY_MIGRATION)) { long k = (start + addr) >> TARGET_PAGE_BITS; if (!test_and_set_bit(k, dest)) { num_dirty++; } - cpu_physical_memory_reset_dirty(start + addr, - TARGET_PAGE_SIZE, - DIRTY_MEMORY_MIGRATION); } } } |