This option is only meaningful when sqthread_poll and sqthread_poll_cpu
are both set. If this option is effective, for multiple io_uring instances
which are all bound to one same cpu, only one kernel thread is created for
this cpu to perform these io_uring instances' submission queue polling.
Signed-off-by: Xiaoguang Wang <xiaoguang.wang@xxxxxxxxxxxxxxxxx>
---
engines/io_uring.c | 12 ++++++++++++
fio.1 | 6 ++++++
os/linux/io_uring.h | 1 +
3 files changed, 19 insertions(+)
diff --git a/engines/io_uring.c b/engines/io_uring.c
index b962e804..638e5b71 100644
--- a/engines/io_uring.c
+++ b/engines/io_uring.c
@@ -78,6 +78,7 @@ struct ioring_options {
unsigned int fixedbufs;
unsigned int registerfiles;
unsigned int sqpoll_thread;
+ unsigned int sqpoll_thread_percpu;
unsigned int sqpoll_set;
unsigned int sqpoll_cpu;
unsigned int nonvectored;
@@ -162,6 +163,15 @@ static struct fio_option options[] = {
.category = FIO_OPT_C_ENGINE,
.group = FIO_OPT_G_IOURING,
},
+ {
+ .name = "sqthread_poll_percpu",
+ .lname = "Kernel percpu SQ thread polling",
+ .type = FIO_OPT_INT,
+ .off1 = offsetof(struct ioring_options, sqpoll_thread_percpu),
+ .help = "Offload submission/completion to kernel thread, use percpu thread",
+ .category = FIO_OPT_C_ENGINE,
+ .group = FIO_OPT_G_IOURING,
+ },
{
.name = "sqthread_poll_cpu",
.lname = "SQ Thread Poll CPU",
@@ -615,6 +625,8 @@ static int fio_ioring_queue_init(struct thread_data *td)
p.flags |= IORING_SETUP_IOPOLL;
if (o->sqpoll_thread) {
p.flags |= IORING_SETUP_SQPOLL;
+ if (o->sqpoll_thread_percpu)
+ p.flags |= IORING_SETUP_SQ_PERCPU;
if (o->sqpoll_set) {
p.flags |= IORING_SETUP_SQ_AFF;
p.sq_thread_cpu = o->sqpoll_cpu;
diff --git a/fio.1 b/fio.1
index ad4a662b..7925a511 100644
--- a/fio.1
+++ b/fio.1
@@ -1925,6 +1925,12 @@ the cost of using more CPU in the system.
When `sqthread_poll` is set, this option provides a way to define which CPU
should be used for the polling thread.
.TP
+.BI (io_uring)sqthread_poll_percpu
+This option is only meaningful when `sqthread_poll` and `sqthread_poll_cpu` are
+both set. If this option is effective, for multiple io_uring instances which are all
+bound to one same cpu, only one polling thread in the kernel is created to perform
+these io_uring instances' submission queue polling.
+.TP
.BI (libaio)userspace_reap
Normally, with the libaio engine in use, fio will use the
\fBio_getevents\fR\|(3) system call to reap newly returned events. With
diff --git a/os/linux/io_uring.h b/os/linux/io_uring.h
index d39b45fd..7839e487 100644
--- a/os/linux/io_uring.h
+++ b/os/linux/io_uring.h
@@ -99,6 +99,7 @@ enum {
#define IORING_SETUP_CQSIZE (1U << 3) /* app defines CQ size */
#define IORING_SETUP_CLAMP (1U << 4) /* clamp SQ/CQ ring sizes */
#define IORING_SETUP_ATTACH_WQ (1U << 5) /* attach to existing wq */
+#define IORING_SETUP_SQ_PERCPU (1U << 7) /* use percpu SQ poll thread */
enum {
IORING_OP_NOP,
--
2.17.2
