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authorPeter Lieven <pl@kamp.de>2014-01-08 10:08:36 +0100
committerGerd Hoffmann <kraxel@redhat.com>2014-03-10 12:35:04 +0100
commit863d7c91050551def59116f4f3b39fab7f1568f7 (patch)
tree201fa34400a616a8cf3f942fc58b92d3c5bf5dcf /ui
parent12b316d4c173bf07f421ef9dc98ba4b53916066e (diff)
ui/vnc: optimize clearing in find_and_clear_dirty_height()
The following artifical test (just the bitmap operation part) running vnc_update_client 65536 times on a 2560x2048 surface illustrates the performance difference: All bits clean - vnc_update_client_new: 0.07 secs vnc_update_client_new2: 0.07 secs vnc_update_client_old: 10.98 secs All bits dirty - vnc_update_client_new: 11.26 secs - vnc_update_client_new2: 0.29 secs vnc_update_client_old: 20.19 secs Few bits dirty - vnc_update_client_new: 0.07 secs - vnc_update_client_new2: 0.07 secs vnc_update_client_old: 10.98 secs vnc_update_client_new2 shows the performance of vnc_update_client with this patch added. Comparing with the test run of the last patch the performance is at least unchanged while it is significantly improved for the all bits dirty case. Signed-off-by: Peter Lieven <pl@kamp.de> Reviewed-by: Wenchao Xia <xiawenc@linux.vnet.ibm.com> Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Diffstat (limited to 'ui')
-rw-r--r--ui/vnc.c5
1 files changed, 1 insertions, 4 deletions
diff --git a/ui/vnc.c b/ui/vnc.c
index 1ed360adf2..e1d6ca323e 100644
--- a/ui/vnc.c
+++ b/ui/vnc.c
@@ -879,13 +879,10 @@ static int find_and_clear_dirty_height(struct VncState *vs,
int h;
for (h = 1; h < (height - y); h++) {
- int tmp_x;
if (!test_bit(last_x, vs->dirty[y + h])) {
break;
}
- for (tmp_x = last_x; tmp_x < x; tmp_x++) {
- clear_bit(tmp_x, vs->dirty[y + h]);
- }
+ bitmap_clear(vs->dirty[y + h], last_x, x - last_x);
}
return h;