Allow binding KNI thread to specific core in single threaded mode
by setting core_id and force_bind config parameters.
Signed-off-by: Vladyslav Buslov <vladyslav.buslov at harmonicinc.com>
---
v2:
* Fixed formatting.
* Refactored kthread create/bind functionality into separate function.
* Moved thread mode print into kni_init.
* Added short description to KNI Programmer's Gude doc.
* Fixed outdated mbuf processing description in KNI Programmer's Gude doc.
doc/guides/prog_guide/kernel_nic_interface.rst | 5 +-
lib/librte_eal/linuxapp/kni/kni_misc.c | 72 +++++++++++++++++---------
2 files changed, 51 insertions(+), 26 deletions(-)
diff --git a/doc/guides/prog_guide/kernel_nic_interface.rst
b/doc/guides/prog_guide/kernel_nic_interface.rst
index fac1960..0fdc307 100644
--- a/doc/guides/prog_guide/kernel_nic_interface.rst
+++ b/doc/guides/prog_guide/kernel_nic_interface.rst
@@ -102,6 +102,9 @@ Refer to rte_kni_common.h in the DPDK source code for more
details.
The physical addresses will be re-mapped into the kernel address space and
stored in separate KNI contexts.
+The affinity of kernel RX thread (both single and multi-threaded modes) is
controlled by force_bind and
+core_id config parameters.
+
The KNI interfaces can be deleted by a DPDK application dynamically after
being created.
Furthermore, all those KNI interfaces not deleted will be deleted on the
release operation
of the miscellaneous device (when the DPDK application is closed).
@@ -128,7 +131,7 @@ Use Case: Ingress
On the DPDK RX side, the mbuf is allocated by the PMD in the RX thread context.
This thread will enqueue the mbuf in the rx_q FIFO.
The KNI thread will poll all KNI active devices for the rx_q.
-If an mbuf is dequeued, it will be converted to a sk_buff and sent to the net
stack via netif_rx().
+If an mbuf is dequeued, it will be converted to a sk_buff and sent to the net
stack via netif_rx_ni().
The dequeued mbuf must be freed, so the same pointer is sent back in the
free_q FIFO.
The RX thread, in the same main loop, polls this FIFO and frees the mbuf after
dequeuing it.
diff --git a/lib/librte_eal/linuxapp/kni/kni_misc.c
b/lib/librte_eal/linuxapp/kni/kni_misc.c
index 5e7cf21..c79f5a8 100644
--- a/lib/librte_eal/linuxapp/kni/kni_misc.c
+++ b/lib/librte_eal/linuxapp/kni/kni_misc.c
@@ -172,6 +172,11 @@ kni_init(void)
return -EINVAL;
}
+ if (multiple_kthread_on == 0)
+ KNI_PRINT("Single kernel thread for all KNI devices\n");
+ else
+ KNI_PRINT("Multiple kernel thread mode enabled\n");
+
#ifdef HAVE_SIMPLIFIED_PERNET_OPERATIONS
rc = register_pernet_subsys(&kni_net_ops);
#else
@@ -240,12 +245,6 @@ kni_open(struct inode *inode, struct file *file)
if (test_and_set_bit(KNI_DEV_IN_USE_BIT_NUM, &knet->device_in_use))
return -EBUSY;
- /* Create kernel thread for single mode */
- if (multiple_kthread_on == 0)
- KNI_PRINT("Single kernel thread for all KNI devices\n");
- else
- KNI_PRINT("Multiple kernel thread mode enabled\n");
-
file->private_data = get_net(net);
KNI_PRINT("/dev/kni opened\n");
@@ -391,6 +390,32 @@ kni_check_param(struct kni_dev *kni, struct
rte_kni_device_info *dev)
return 0;
}
+__printf(5, 6) static struct task_struct *
+kni_run_thread(int (*threadfn)(void *data),
+ void *data,
+ uint8_t force_bind,
+ unsigned core_id,
+ const char namefmt[], ...)
+{
+ struct task_struct *kni_thread = NULL;
+ char task_comm[TASK_COMM_LEN];
+ va_list args;
+
+ va_start(args, namefmt);
+ vsnprintf(task_comm, sizeof(task_comm), namefmt, args);
+ va_end(args);
+
+ kni_thread = kthread_create(threadfn, data, task_comm);
+ if (IS_ERR(kni_thread))
+ return NULL;
+
+ if (force_bind)
+ kthread_bind(kni_thread, core_id);
+ wake_up_process(kni_thread);
+
+ return kni_thread;
+}
+
static int
kni_ioctl_create(struct net *net,
unsigned int ioctl_num, unsigned long ioctl_param)
@@ -419,8 +444,7 @@ kni_ioctl_create(struct net *net,
/**
* Check if the cpu core id is valid for binding.
*/
- if (dev_info.force_bind &&
- !cpu_online(dev_info.core_id)) {
+ if (dev_info.force_bind && !cpu_online(dev_info.core_id)) {
KNI_ERR("cpu %u is not online\n", dev_info.core_id);
return -EINVAL;
}
@@ -572,31 +596,29 @@ kni_ioctl_create(struct net *net,
* and finally wake it up.
*/
if (multiple_kthread_on) {
- kni->pthread = kthread_create(kni_thread_multiple,
- (void *)kni,
- "kni_%s", kni->name);
- if (IS_ERR(kni->pthread)) {
+ kni->pthread = kni_run_thread(kni_thread_multiple,
+ (void *)kni,
+ dev_info.force_bind,
+ kni->core_id,
+ "kni_%s", kni->name);
+ if (kni->pthread == NULL) {
kni_dev_remove(kni);
return -ECANCELED;
}
- if (dev_info.force_bind)
- kthread_bind(kni->pthread, kni->core_id);
- wake_up_process(kni->pthread);
} else {
mutex_lock(&knet->kni_kthread_lock);
if (knet->kni_kthread == NULL) {
- knet->kni_kthread = kthread_create(kni_thread_single,
- (void
*)knet,
-
"kni_single");
- if (IS_ERR(knet->kni_kthread)) {
- kni_dev_remove(kni);
- return -ECANCELED;
- }
- if (dev_info.force_bind)
- kthread_bind(knet->kni_kthread, kni->core_id);
- wake_up_process(knet->kni_kthread);
+ knet->kni_kthread = kni_run_thread(kni_thread_single,
+ (void *)knet,
+ dev_info.force_bind,
+ kni->core_id,
+ "kni_single");
}
mutex_unlock(&knet->kni_kthread_lock);
+ if (knet->kni_kthread == NULL) {
+ kni_dev_remove(kni);
+ return -ECANCELED;
+ }
}
down_write(&knet->kni_list_lock);
--
2.8.3
