ShuriZma
/
xemu
mirror of https://github.com/xemu-project/xemu.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

memory: make cpu_physical_memory_sync_dirty_bitmap() fully atomic 

The fast path of cpu_physical_memory_sync_dirty_bitmap() directly
manipulates the dirty bitmap.  Use atomic_xchg() to make the
test-and-clear atomic.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <1417519399-3166-7-git-send-email-stefanha@redhat.com>
[Only do xchg on nonzero words. - Paolo]
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Stefan Hajnoczi 2014-12-02 11:23:19 +00:00 committed by Paolo Bonzini
parent 03eebc9e32
commit 5f2cb94688
1 changed files with 3 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
include/exec/ram_addr.h
View File

@ -224,12 +224,12 @@ uint64_t cpu_physical_memory_sync_dirty_bitmap(unsigned long *dest,
for (k = page; k < page + nr; k++) {
if (src[k]) {
unsigned long bits = atomic_xchg(&src[k], 0);
unsigned long new_dirty;
new_dirty = ~dest[k];
dest[k] |= src[k];
new_dirty &= src[k];
dest[k] |= bits;
new_dirty &= bits;
num_dirty += ctpopl(new_dirty);
src[k] = 0;
}
}
} else {