On 07/13/2016 06:21 PM, Paolo Bonzini wrote:
On 13/07/2016 11:06, Cao jin wrote:
When passed argument 'ns' is 0, macro DIV_ROUND_UP will return 0 also.
It's potentially slower though.
Is it because the function in the i/o loop path, so the potentially
extra arithmetical instructions matters?
Paolo
Cc: Paolo Bonzini <pbonz...@redhat.com>
Signed-off-by: Cao jin <caoj.f...@cn.fujitsu.com>
---
qemu-timer.c | 6 +-----
1 file changed, 1 insertion(+), 5 deletions(-)
diff --git a/qemu-timer.c b/qemu-timer.c
index eb22e92..cfe0893 100644
--- a/qemu-timer.c
+++ b/qemu-timer.c
@@ -285,12 +285,8 @@ int qemu_timeout_ns_to_ms(int64_t ns)
return -1;
}
- if (!ns) {
- return 0;
- }
-
/* Always round up, because it's better to wait too long than to wait too
- * little and effectively busy-wait
+ * short and effectively busy-wait
*/
ms = DIV_ROUND_UP(ns, SCALE_MS);
--
Yours Sincerely,
Cao jin
