Currently, timers run on iothread inside QBL, this limits the usage
of timers in some case, e.g. virtio-blk-dataplane. In order to run
timers on private thread based on different clocksource, we arm each
AioContext with three timer lists in according to three clocksource
(QemuClock).
A little later, we will run timers in aio_poll.
Signed-off-by: Liu Ping Fan <pingf...@linux.vnet.ibm.com>
------ issue to fix ---
Note: before this patch, there should be another one to fix the race
issue by qemu_mod_timer() and _run_timers().
---
async.c | 9 ++++++++
include/block/aio.h | 13 +++++++++++
include/qemu/timer.h | 20 ++++++++++++++++
qemu-timer.c | 65 +++++++++++++++++++++++++++++++---------------------
4 files changed, 81 insertions(+), 26 deletions(-)
diff --git a/async.c b/async.c
index ba4072c..7e2340e 100644
--- a/async.c
+++ b/async.c
@@ -201,11 +201,15 @@ static void
aio_ctx_finalize(GSource *source)
{
AioContext *ctx = (AioContext *) source;
+ int i;
thread_pool_free(ctx->thread_pool);
aio_set_event_notifier(ctx, &ctx->notifier, NULL, NULL);
event_notifier_cleanup(&ctx->notifier);
g_array_free(ctx->pollfds, TRUE);
+ for (i = 0; i < QEMU_CLOCK_MAXCNT; i++) {
+ timer_list_finalize(&ctx->timer_list[i]);
+ }
}
static GSourceFuncs aio_source_funcs = {
@@ -237,6 +241,8 @@ void aio_notify(AioContext *ctx)
AioContext *aio_context_new(void)
{
AioContext *ctx;
+ int i;
+
ctx = (AioContext *) g_source_new(&aio_source_funcs, sizeof(AioContext));
ctx->pollfds = g_array_new(FALSE, FALSE, sizeof(GPollFD));
ctx->thread_pool = NULL;
@@ -245,6 +251,9 @@ AioContext *aio_context_new(void)
aio_set_event_notifier(ctx, &ctx->notifier,
(EventNotifierHandler *)
event_notifier_test_and_clear, NULL);
+ for (i = 0; i < QEMU_CLOCK_MAXCNT; i++) {
+ timer_list_init(&ctx->timer_list[i]);
+ }
return ctx;
}
diff --git a/include/block/aio.h b/include/block/aio.h
index 04598b2..cf41b42 100644
--- a/include/block/aio.h
+++ b/include/block/aio.h
@@ -43,6 +43,18 @@ typedef struct AioHandler AioHandler;
typedef void QEMUBHFunc(void *opaque);
typedef void IOHandler(void *opaque);
+/* Related timer with AioContext */
+typedef struct QEMUTimer QEMUTimer;
+#define QEMU_CLOCK_MAXCNT 3
+
+typedef struct TimerList {
+ QEMUTimer *active_timers;
+ QemuMutex active_timers_lock;
+} TimerList;
+
+void timer_list_init(TimerList *tlist);
+void timer_list_finalize(TimerList *tlist);
+
typedef struct AioContext {
GSource source;
@@ -73,6 +85,7 @@ typedef struct AioContext {
/* Thread pool for performing work and receiving completion callbacks */
struct ThreadPool *thread_pool;
+ TimerList timer_list[QEMU_CLOCK_MAXCNT];
} AioContext;
/* Returns 1 if there are still outstanding AIO requests; 0 otherwise */
diff --git a/include/qemu/timer.h b/include/qemu/timer.h
index 9dd206c..3e5016b 100644
--- a/include/qemu/timer.h
+++ b/include/qemu/timer.h
@@ -33,9 +33,14 @@ extern QEMUClock *vm_clock;
extern QEMUClock *host_clock;
int64_t qemu_get_clock_ns(QEMUClock *clock);
+/* qemu_clock_has_timers, qemu_clock_expired, qemu_clock_deadline
+ * run In tcg icount mode. There is only one AioContext i.e. qemu_aio_context.
+ * So we only count the timers on qemu_aio_context.
+ */
int64_t qemu_clock_has_timers(QEMUClock *clock);
int64_t qemu_clock_expired(QEMUClock *clock);
int64_t qemu_clock_deadline(QEMUClock *clock);
+
void qemu_clock_enable(QEMUClock *clock, bool enabled);
void qemu_clock_warp(QEMUClock *clock);
@@ -45,6 +50,9 @@ void qemu_unregister_clock_reset_notifier(QEMUClock *clock,
QEMUTimer *qemu_new_timer(QEMUClock *clock, int scale,
QEMUTimerCB *cb, void *opaque);
+QEMUTimer *aioctx_new_timer(QEMUClock *clock, int scale,
+ QEMUTimerCB *cb, void *opaque, AioContext *ctx);
+
void qemu_free_timer(QEMUTimer *ts);
void qemu_del_timer(QEMUTimer *ts);
void qemu_mod_timer_ns(QEMUTimer *ts, int64_t expire_time);
@@ -75,6 +83,18 @@ static inline QEMUTimer *qemu_new_timer_ms(QEMUClock *clock,
QEMUTimerCB *cb,
return qemu_new_timer(clock, SCALE_MS, cb, opaque);
}
+static inline QEMUTimer *aioctx_new_timer_ns(QEMUClock *clock, QEMUTimerCB *cb,
+ void *opaque, AioContext *ctx)
+{
+ return aioctx_new_timer(clock, SCALE_NS, cb, opaque, ctx);
+}
+
+static inline QEMUTimer *aioctx_new_timer_ms(QEMUClock *clock, QEMUTimerCB *cb,
+ void *opaque, AioContext *ctx)
+{
+ return aioctx_new_timer(clock, SCALE_MS, cb, opaque, ctx);
+}
+
static inline int64_t qemu_get_clock_ms(QEMUClock *clock)
{
return qemu_get_clock_ns(clock) / SCALE_MS;
diff --git a/qemu-timer.c b/qemu-timer.c
index d941a83..f15c3e6 100644
--- a/qemu-timer.c
+++ b/qemu-timer.c
@@ -45,14 +45,6 @@
#define QEMU_CLOCK_REALTIME 0
#define QEMU_CLOCK_VIRTUAL 1
#define QEMU_CLOCK_HOST 2
-#define QEMU_CLOCK_MAXCNT 3
-
-typedef struct TimerList {
- QEMUTimer *active_timers;
- QemuMutex active_timers_lock;
-} TimerList;
-
-static TimerList timer_list[QEMU_CLOCK_MAXCNT];
struct QEMUClock {
NotifierList reset_notifiers;
@@ -72,7 +64,9 @@ struct QEMUClock {
struct QEMUTimer {
int64_t expire_time; /* in nanoseconds */
+ /* quick link to AioContext timer list */
TimerList *list;
+ AioContext *ctx;
QEMUTimerCB *cb;
void *opaque;
QEMUTimer *next;
@@ -100,11 +94,12 @@ struct qemu_alarm_timer {
static struct qemu_alarm_timer *alarm_timer;
-static TimerList *clock_to_timerlist(QEMUClock *clock)
+static TimerList *clock_to_timerlist(QEMUClock *clock, AioContext *ctx)
{
int type = clock->type;
- return &timer_list[type];
+ assert(ctx);
+ return &ctx->timer_list[type];
}
static bool qemu_timer_expired_ns(QEMUTimer *timer_head, int64_t current_time)
@@ -112,7 +107,8 @@ static bool qemu_timer_expired_ns(QEMUTimer *timer_head,
int64_t current_time)
return timer_head && (timer_head->expire_time <= current_time);
}
-static int64_t qemu_next_clock_deadline(QEMUClock *clock, int64_t delta)
+static int64_t qemu_next_clock_deadline(QEMUClock *clock, int64_t delta,
+ AioContext *ctx)
{
int64_t expire_time, next;
bool has_timer = false;
@@ -122,7 +118,7 @@ static int64_t qemu_next_clock_deadline(QEMUClock *clock,
int64_t delta)
return delta;
}
- tlist = clock_to_timerlist(clock);
+ tlist = clock_to_timerlist(clock, ctx);
qemu_mutex_lock(&tlist->active_timers_lock);
if (tlist->active_timers) {
has_timer = true;
@@ -140,12 +136,13 @@ static int64_t qemu_next_clock_deadline(QEMUClock *clock,
int64_t delta)
static int64_t qemu_next_alarm_deadline(void)
{
int64_t delta = INT64_MAX;
+ AioContext *ctx = *tls_get_thread_aio_context();
if (!use_icount) {
- delta = qemu_next_clock_deadline(vm_clock, delta);
+ delta = qemu_next_clock_deadline(vm_clock, delta, ctx);
}
- delta = qemu_next_clock_deadline(host_clock, delta);
- return qemu_next_clock_deadline(rt_clock, delta);
+ delta = qemu_next_clock_deadline(host_clock, delta, ctx);
+ return qemu_next_clock_deadline(rt_clock, delta, ctx);
}
static void qemu_rearm_alarm_timer(struct qemu_alarm_timer *t)
@@ -267,16 +264,21 @@ QEMUClock *rt_clock;
QEMUClock *vm_clock;
QEMUClock *host_clock;
-static void timer_list_init(TimerList *tlist)
+void timer_list_init(TimerList *tlist)
{
qemu_mutex_init(&tlist->active_timers_lock);
tlist->active_timers = NULL;
}
+void timer_list_finalize(TimerList *tlist)
+{
+ qemu_mutex_destroy(&tlist->active_timers_lock);
+ assert(!tlist->active_timers);
+}
+
static QEMUClock *qemu_new_clock(int type)
{
QEMUClock *clock;
- TimerList *tlist;
clock = g_malloc0(sizeof(QEMUClock));
clock->type = type;
@@ -286,8 +288,6 @@ static QEMUClock *qemu_new_clock(int type)
qemu_cond_init(&clock->wait_using);
qemu_mutex_init(&clock->lock);
notifier_list_init(&clock->reset_notifiers);
- tlist = clock_to_timerlist(clock);
- timer_list_init(tlist);
return clock;
}
@@ -308,10 +308,14 @@ void qemu_clock_enable(QEMUClock *clock, bool enabled)
}
}
+/* qemu_clock_has_timers, qemu_clock_expired, qemu_clock_deadline
+ * run In tcg icount mode. There is only one AioContext i.e. qemu_aio_context.
+ * So we only count the timers on qemu_aio_context.
+*/
int64_t qemu_clock_has_timers(QEMUClock *clock)
{
bool has_timers;
- TimerList *tlist = clock_to_timerlist(clock);
+ TimerList *tlist = clock_to_timerlist(clock, qemu_get_aio_context());
qemu_mutex_lock(&tlist->active_timers_lock);
has_timers = !!tlist->active_timers;
@@ -323,7 +327,7 @@ int64_t qemu_clock_expired(QEMUClock *clock)
{
bool has_timers;
int64_t expire_time;
- TimerList *tlist = clock_to_timerlist(clock);
+ TimerList *tlist = clock_to_timerlist(clock, qemu_get_aio_context());
qemu_mutex_lock(&tlist->active_timers_lock);
has_timers = tlist->active_timers;
@@ -339,7 +343,7 @@ int64_t qemu_clock_deadline(QEMUClock *clock)
int64_t delta = INT32_MAX;
bool has_timers;
int64_t expire_time;
- TimerList *tlist = clock_to_timerlist(clock);
+ TimerList *tlist = clock_to_timerlist(clock, qemu_get_aio_context());
qemu_mutex_lock(&tlist->active_timers_lock);
has_timers = tlist->active_timers;
@@ -355,19 +359,26 @@ int64_t qemu_clock_deadline(QEMUClock *clock)
return delta;
}
-QEMUTimer *qemu_new_timer(QEMUClock *clock, int scale,
- QEMUTimerCB *cb, void *opaque)
+QEMUTimer *aioctx_new_timer(QEMUClock *clock, int scale,
+ QEMUTimerCB *cb, void *opaque, AioContext *ctx)
{
QEMUTimer *ts;
ts = g_malloc0(sizeof(QEMUTimer));
- ts->list = clock_to_timerlist(clock);
+ ts->list = clock_to_timerlist(clock, ctx);
ts->cb = cb;
ts->opaque = opaque;
ts->scale = scale;
+ ts->ctx = ctx;
return ts;
}
+QEMUTimer *qemu_new_timer(QEMUClock *clock, int scale,
+ QEMUTimerCB *cb, void *opaque)
+{
+ return aioctx_new_timer(clock, scale, cb, opaque, qemu_get_aio_context());
+}
+
void qemu_free_timer(QEMUTimer *ts)
{
g_free(ts);
@@ -457,6 +468,7 @@ void qemu_run_timers(QEMUClock *clock)
QEMUTimer *ts;
int64_t current_time;
TimerList *tlist;
+ AioContext *ctx;
atomic_inc(&clock->using);
if (unlikely(!clock->enabled)) {
@@ -465,7 +477,8 @@ void qemu_run_timers(QEMUClock *clock)
current_time = qemu_get_clock_ns(clock);
- tlist = clock_to_timerlist(clock);
+ ctx = *tls_get_thread_aio_context();
+ tlist = clock_to_timerlist(clock, ctx);
for(;;) {
qemu_mutex_lock(&tlist->active_timers_lock);
--
1.8.1.4
