From 11ef790c7cca491bba62d8cb94018c1cf78e033c Mon Sep 17 00:00:00 2001
From: Juan Quintela <quintela@redhat.com>
Date: Tue, 14 Jan 2014 15:07:36 +0100
Subject: [PATCH 25/40] memory: use find_next_bit() to find dirty bits

RH-Author: Juan Quintela <quintela@redhat.com>
Message-id: <1389712071-23303-26-git-send-email-quintela@redhat.com>
Patchwork-id: 56680
O-Subject: [RHEL7 qemu-kvm PATCH 25/40] memory: use find_next_bit() to find dirty bits
Bugzilla: 997559
RH-Acked-by: Paolo Bonzini <pbonzini@redhat.com>
RH-Acked-by: Orit Wasserman <owasserm@redhat.com>
RH-Acked-by: Dr. David Alan Gilbert (git) <dgilbert@redhat.com>

This operation is way faster than doing it bit by bit.

Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Orit Wasserman <owasserm@redhat.com>
(cherry picked from commit 1bafff0c7cb99972fd243464632eca0780c6a8f1)
Signed-off-by: Juan Quintela <quintela@trasno.org>
---
 include/exec/memory-internal.h | 16 ++++++----------
 1 file changed, 6 insertions(+), 10 deletions(-)

Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
---
 include/exec/memory-internal.h |   16 ++++++----------
 1 files changed, 6 insertions(+), 10 deletions(-)

diff --git a/include/exec/memory-internal.h b/include/exec/memory-internal.h
index caff5b4..1eda526 100644
--- a/include/exec/memory-internal.h
+++ b/include/exec/memory-internal.h
@@ -53,19 +53,15 @@ 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,
-- 
1.7.1