diff mbox

[26/28] memory: use find_next_bit() to find dirty bits

Message ID 1381318130-10620-27-git-send-email-quintela@redhat.com
State New
Headers show

Commit Message

Juan Quintela Oct. 9, 2013, 11:28 a.m. UTC 
This operation is way faster that doing it bit by bit.

Signed-off-by: Juan Quintela <quintela@redhat.com>
---
 include/exec/memory-internal.h | 15 ++++++---------
 1 file changed, 6 insertions(+), 9 deletions(-)

Comments

Eric Blake Oct. 9, 2013, 7:57 p.m. UTC | #1 
On 10/09/2013 05:28 AM, Juan Quintela wrote:
> This operation is way faster that doing it bit by bit.

s/that/than/

> 
> Signed-off-by: Juan Quintela <quintela@redhat.com>
> ---
>  include/exec/memory-internal.h | 15 ++++++---------
>  1 file changed, 6 insertions(+), 9 deletions(-)
diff mbox

Patch

diff --git a/include/exec/memory-internal.h b/include/exec/memory-internal.h
index 0c1dbfa..5a5bc0d 100644
--- a/include/exec/memory-internal.h
+++ b/include/exec/memory-internal.h
@@ -44,18 +44,15 @@  static inline bool cpu_physical_memory_get_dirty(ram_addr_t start,
                                                  ram_addr_t length,
                                                  unsigned client)
 {
-    ram_addr_t addr, end;
+    unsigned long end, page, next;

     assert(client < DIRTY_MEMORY_NUM);

-    end = TARGET_PAGE_ALIGN(start + length);
-    start &= TARGET_PAGE_MASK;
-    for (addr = start; addr < end; addr += TARGET_PAGE_SIZE) {
-        if (test_bit(addr >> TARGET_PAGE_BITS, ram_list.dirty_memory[client])) {
-            return true;
-        }
-    }
-    return false;
+    end = TARGET_PAGE_ALIGN(start + length) >> TARGET_PAGE_BITS;
+    page = start >> TARGET_PAGE_BITS;
+    next = find_next_bit(ram_list.dirty_memory[client], end, page);
+
+    return next < end;
 }

 static inline bool cpu_physical_memory_get_dirty_flag(ram_addr_t addr,