+#
# The @aio-max-batch option is available since 6.1.
#
# Since: 2.0
@@ -614,7 +619,8 @@
'base': 'EventLoopBaseProperties',
'data': { '*poll-max-ns': 'int',
'*poll-grow': 'int',
- '*poll-shrink': 'int' } }
+ '*poll-shrink': 'int',
+ '*poll-weight': 'int' } }
##
# @MainLoopProperties:
diff --git a/qemu-options.hx b/qemu-options.hx
index 69e5a874c1..8ddf6c8d36 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -6413,7 +6413,7 @@ SRST
CN=laptop.example.com,O=Example Home,L=London,ST=London,C=GB
- ``-object iothread,id=id,poll-max-ns=poll-max-ns,poll-grow=poll-grow,poll-shrink=poll-shrink,aio-max-batch=aio-max-batch``
+ ``-object
iothread,id=id,poll-max-ns=poll-max-ns,poll-grow=poll-grow,poll-shrink=poll-shrink,poll-weight=poll-weight,aio-max-batch=aio-max-batch``
Creates a dedicated event loop thread that devices can be
assigned to. This is known as an IOThread. By default device
emulation happens in vCPU threads or the main event loop thread.
@@ -6449,6 +6449,11 @@ SRST
the polling time when the algorithm detects it is spending too
long polling without encountering events.
+ The ``poll-weight`` parameter is the weight factor used in the
+ adaptive polling algorithm. It determines how much the most
+ recent event interval affects the calculation of the next
+ polling duration.
+
The ``aio-max-batch`` parameter is the maximum number of requests
in a batch for the AIO engine, 0 means that the engine will use
its default.
diff --git a/tests/unit/test-nested-aio-poll.c
b/tests/unit/test-nested-aio-poll.c
index 9ab1ad08a7..4c38f36fd4 100644
--- a/tests/unit/test-nested-aio-poll.c
+++ b/tests/unit/test-nested-aio-poll.c
@@ -81,7 +81,7 @@ static void test(void)
qemu_set_current_aio_context(td.ctx);
/* Enable polling */
- aio_context_set_poll_params(td.ctx, 1000000, 2, 2, &error_abort);
+ aio_context_set_poll_params(td.ctx, 1000000, 2, 2, 3, &error_abort);
/* Make the event notifier active (set) right away */
event_notifier_init(&td.poll_notifier, 1);
diff --git a/util/aio-posix.c b/util/aio-posix.c
index 2b3522f2f9..13b7f94911 100644
--- a/util/aio-posix.c
+++ b/util/aio-posix.c
@@ -29,7 +29,6 @@
/* Stop userspace polling on a handler if it isn't active for some time */
#define POLL_IDLE_INTERVAL_NS (7 * NANOSECONDS_PER_SECOND)
-#define POLL_WEIGHT_SHIFT (3)
static void adjust_block_ns(AioContext *ctx, int64_t block_ns);
static void grow_polling_time(AioContext *ctx, int64_t block_ns);
@@ -593,10 +592,6 @@ static void shrink_polling_time(AioContext *ctx, int64_t
block_ns)
int64_t old = ctx->poll_ns;
int64_t shrink = ctx->poll_shrink;
- if (shrink == 0) {
- shrink = 2;
- }
-
if (block_ns < (ctx->poll_ns / shrink)) {
ctx->poll_ns /= shrink;
}
@@ -610,10 +605,6 @@ static void grow_polling_time(AioContext *ctx, int64_t
block_ns)
int64_t old = ctx->poll_ns;
int64_t grow = ctx->poll_grow;
- if (grow == 0) {
- grow = 2;
- }
-
if (block_ns > ctx->poll_ns * grow) {
ctx->poll_ns = block_ns;
} else {
@@ -640,8 +631,8 @@ static void adjust_block_ns(AioContext *ctx, int64_t
block_ns)
* poll.ns to smooth out polling time adjustments.
*/
node->poll.ns = node->poll.ns
- ? (node->poll.ns - (node->poll.ns >> POLL_WEIGHT_SHIFT))
- + (block_ns >> POLL_WEIGHT_SHIFT) : block_ns;
+ ? (node->poll.ns - (node->poll.ns >> ctx->poll_weight))
+ + (block_ns >> ctx->poll_weight) : block_ns;
if (node->poll.ns > ctx->poll_max_ns) {
node->poll.ns = 0;
@@ -831,7 +822,8 @@ void aio_context_destroy(AioContext *ctx)
}
void aio_context_set_poll_params(AioContext *ctx, int64_t max_ns,
- int64_t grow, int64_t shrink, Error **errp)
+ int64_t grow, int64_t shrink,
+ int64_t weight, Error **errp)
{
AioHandler *node;
@@ -848,6 +840,7 @@ void aio_context_set_poll_params(AioContext *ctx, int64_t max_ns,
ctx->poll_max_ns = max_ns;
ctx->poll_grow = grow;
ctx->poll_shrink = shrink;
+ ctx->poll_weight = weight;
ctx->poll_ns = 0;
aio_notify(ctx);
