Some async jobs do not need the BQL.
Reviewed-by: Richard Henderson <richard.hender...@linaro.org>
Reviewed-by: Alex Bennée <alex.ben...@linaro.org>
Signed-off-by: Emilio G. Cota <c...@braap.org>
---
include/qom/cpu.h | 14 ++++++++++++++
cpus-common.c | 39 ++++++++++++++++++++++++++++++++++-----
2 files changed, 48 insertions(+), 5 deletions(-)
diff --git a/include/qom/cpu.h b/include/qom/cpu.h
index 44e6e83ecd..f75f5e74ca 100644
--- a/include/qom/cpu.h
+++ b/include/qom/cpu.h
@@ -898,9 +898,23 @@ void run_on_cpu(CPUState *cpu, run_on_cpu_func func,
run_on_cpu_data data);
* @data: Data to pass to the function.
*
* Schedules the function @func for execution on the vCPU @cpu asynchronously.
+ * See also: async_run_on_cpu_no_bql()
*/
void async_run_on_cpu(CPUState *cpu, run_on_cpu_func func, run_on_cpu_data
data);
+/**
+ * async_run_on_cpu_no_bql:
+ * @cpu: The vCPU to run on.
+ * @func: The function to be executed.
+ * @data: Data to pass to the function.
+ *
+ * Schedules the function @func for execution on the vCPU @cpu asynchronously.
+ * This function is run outside the BQL.
+ * See also: async_run_on_cpu()
+ */
+void async_run_on_cpu_no_bql(CPUState *cpu, run_on_cpu_func func,
+ run_on_cpu_data data);
+
/**
* async_safe_run_on_cpu:
* @cpu: The vCPU to run on.
diff --git a/cpus-common.c b/cpus-common.c
index 1241024b2c..5832a8bf37 100644
--- a/cpus-common.c
+++ b/cpus-common.c
@@ -109,6 +109,7 @@ struct qemu_work_item {
run_on_cpu_func func;
run_on_cpu_data data;
bool free, exclusive, done;
+ bool bql;
};
/* Called with the CPU's lock held */
@@ -155,6 +156,7 @@ void run_on_cpu(CPUState *cpu, run_on_cpu_func func,
run_on_cpu_data data)
wi.done = false;
wi.free = false;
wi.exclusive = false;
+ wi.bql = true;
cpu_mutex_lock(cpu);
queue_work_on_cpu_locked(cpu, &wi);
@@ -179,6 +181,21 @@ void async_run_on_cpu(CPUState *cpu, run_on_cpu_func func,
run_on_cpu_data data)
wi->func = func;
wi->data = data;
wi->free = true;
+ wi->bql = true;
+
+ queue_work_on_cpu(cpu, wi);
+}
+
+void async_run_on_cpu_no_bql(CPUState *cpu, run_on_cpu_func func,
+ run_on_cpu_data data)
+{
+ struct qemu_work_item *wi;
+
+ wi = g_malloc0(sizeof(struct qemu_work_item));
+ wi->func = func;
+ wi->data = data;
+ wi->free = true;
+ /* wi->bql initialized to false */
queue_work_on_cpu(cpu, wi);
}
@@ -323,6 +340,7 @@ void async_safe_run_on_cpu(CPUState *cpu, run_on_cpu_func
func,
wi->data = data;
wi->free = true;
wi->exclusive = true;
+ /* wi->bql initialized to false */
queue_work_on_cpu(cpu, wi);
}
@@ -347,6 +365,7 @@ static void process_queued_cpu_work_locked(CPUState *cpu)
* BQL, so it goes to sleep; start_exclusive() is sleeping too, so
* neither CPU can proceed.
*/
+ g_assert(!wi->bql);
if (has_bql) {
qemu_mutex_unlock_iothread();
}
@@ -357,12 +376,22 @@ static void process_queued_cpu_work_locked(CPUState *cpu)
qemu_mutex_lock_iothread();
}
} else {
- if (has_bql) {
- wi->func(cpu, wi->data);
+ if (wi->bql) {
+ if (has_bql) {
+ wi->func(cpu, wi->data);
+ } else {
+ qemu_mutex_lock_iothread();
+ wi->func(cpu, wi->data);
+ qemu_mutex_unlock_iothread();
+ }
} else {
- qemu_mutex_lock_iothread();
- wi->func(cpu, wi->data);
- qemu_mutex_unlock_iothread();
+ if (has_bql) {
+ qemu_mutex_unlock_iothread();
+ wi->func(cpu, wi->data);
+ qemu_mutex_lock_iothread();
+ } else {
+ wi->func(cpu, wi->data);
+ }
}
}
cpu_mutex_lock(cpu);
--
2.17.1
