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authorPeter Maydell <peter.maydell@linaro.org>2017-02-03 14:41:48 +0000
committerPeter Maydell <peter.maydell@linaro.org>2017-02-03 14:41:49 +0000
commita951316b8a5c3c63254f20a826afeed940dd4cba (patch)
tree1aa7d07d263b705c790a3c9a3d1a1fc5c9b273f9
parent4100a344eb3d50d88f9da85cae334afc47aee134 (diff)
parentcdd7abfdba9287a289c404dfdcb02316f9ffee7d (diff)
Merge remote-tracking branch 'remotes/stefanha/tags/block-pull-request' into staging
# gpg: Signature made Fri 03 Feb 2017 14:37:45 GMT # gpg: using RSA key 0x9CA4ABB381AB73C8 # gpg: Good signature from "Stefan Hajnoczi <stefanha@redhat.com>" # gpg: aka "Stefan Hajnoczi <stefanha@gmail.com>" # Primary key fingerprint: 8695 A8BF D3F9 7CDA AC35 775A 9CA4 ABB3 81AB 73C8 * remotes/stefanha/tags/block-pull-request: iothread: enable AioContext polling by default Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
-rw-r--r--iothread.c14
1 files changed, 14 insertions, 0 deletions
diff --git a/iothread.c b/iothread.c
index 7bedde87e9..257b01d5f1 100644
--- a/iothread.c
+++ b/iothread.c
@@ -30,6 +30,12 @@ typedef ObjectClass IOThreadClass;
#define IOTHREAD_CLASS(klass) \
OBJECT_CLASS_CHECK(IOThreadClass, klass, TYPE_IOTHREAD)
+/* Benchmark results from 2016 on NVMe SSD drives show max polling times around
+ * 16-32 microseconds yield IOPS improvements for both iodepth=1 and iodepth=32
+ * workloads.
+ */
+#define IOTHREAD_POLL_MAX_NS_DEFAULT 32768ULL
+
static __thread IOThread *my_iothread;
AioContext *qemu_get_current_aio_context(void)
@@ -71,6 +77,13 @@ static int iothread_stop(Object *object, void *opaque)
return 0;
}
+static void iothread_instance_init(Object *obj)
+{
+ IOThread *iothread = IOTHREAD(obj);
+
+ iothread->poll_max_ns = IOTHREAD_POLL_MAX_NS_DEFAULT;
+}
+
static void iothread_instance_finalize(Object *obj)
{
IOThread *iothread = IOTHREAD(obj);
@@ -215,6 +228,7 @@ static const TypeInfo iothread_info = {
.parent = TYPE_OBJECT,
.class_init = iothread_class_init,
.instance_size = sizeof(IOThread),
+ .instance_init = iothread_instance_init,
.instance_finalize = iothread_instance_finalize,
.interfaces = (InterfaceInfo[]) {
{TYPE_USER_CREATABLE},