A common task for most drivers is to remember the user-set CPU affinity
to its IRQs. On each netdev reset, the driver should re-assign the
user's settings to the IRQs.
Add CPU affinity mask to napi_config. To delegate the CPU affinity
management to the core, drivers must:
1 - set the new netdev flag "irq_affinity_auto":
netif_enable_irq_affinity(netdev)
2 - create the napi with persistent config:
netif_napi_add_config()
3 - bind an IRQ to the napi instance: netif_napi_set_irq()
the core will then make sure to use re-assign affinity to the napi's
IRQ.
The default IRQ mask is set to one cpu starting from the closest NUMA.
Signed-off-by: Ahmed Zaki <ahmed.z...@intel.com>
---
include/linux/netdevice.h | 14 ++++++++++-
net/core/dev.c | 51 +++++++++++++++++++++++++++++----------
2 files changed, 51 insertions(+), 14 deletions(-)
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 98259f19c627..d576e5c91c43 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -351,6 +351,7 @@ struct napi_config {
u64 gro_flush_timeout;
u64 irq_suspend_timeout;
u32 defer_hard_irqs;
+ cpumask_t affinity_mask;
unsigned int napi_id;
};
@@ -393,8 +394,8 @@ struct napi_struct {
struct list_head dev_list;
struct hlist_node napi_hash_node;
int irq;
-#ifdef CONFIG_RFS_ACCEL
struct irq_affinity_notify notify;
+#ifdef CONFIG_RFS_ACCEL
int napi_rmap_idx;
#endif
int index;
@@ -1991,6 +1992,11 @@ enum netdev_reg_state {
*
* @threaded: napi threaded mode is enabled
*
+ * @irq_affinity_auto: driver wants the core to manage the IRQ affinity.
+ * Set by netif_enable_irq_affinity(), then driver must
+ * create persistent napi by netif_napi_add_config()
+ * and finally bind napi to IRQ (netif_napi_set_irq).
+ *
* @rx_cpu_rmap_auto: driver wants the core to manage the ARFS rmap.
* Set by calling netif_enable_cpu_rmap().
*
@@ -2401,6 +2407,7 @@ struct net_device {
struct lock_class_key *qdisc_tx_busylock;
bool proto_down;
bool threaded;
+ bool irq_affinity_auto;
bool rx_cpu_rmap_auto;
/* priv_flags_slow, ungrouped to save space */
@@ -2653,6 +2660,11 @@ static inline void netdev_set_ml_priv(struct net_device
*dev,
dev->ml_priv_type = type;
}
+static inline void netif_enable_irq_affinity(struct net_device *dev)
+{
+ dev->irq_affinity_auto = true;
+}
+
/*
* Net namespace inlines
*/
diff --git a/net/core/dev.c b/net/core/dev.c
index dbb63005bc2b..bc82c7f621b3 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -6862,24 +6862,31 @@ void netif_queue_set_napi(struct net_device *dev,
unsigned int queue_index,
}
EXPORT_SYMBOL(netif_queue_set_napi);
-#ifdef CONFIG_RFS_ACCEL
static void
-netif_irq_cpu_rmap_notify(struct irq_affinity_notify *notify,
- const cpumask_t *mask)
+netif_napi_irq_notify(struct irq_affinity_notify *notify,
+ const cpumask_t *mask)
{
struct napi_struct *napi =
container_of(notify, struct napi_struct, notify);
+#ifdef CONFIG_RFS_ACCEL
struct cpu_rmap *rmap = napi->dev->rx_cpu_rmap;
int err;
+#endif
+ if (napi->config && napi->dev->irq_affinity_auto)
+ cpumask_copy(&napi->config->affinity_mask, mask);
+
+#ifdef CONFIG_RFS_ACCEL
if (napi->dev->rx_cpu_rmap_auto) {
err = cpu_rmap_update(rmap, napi->napi_rmap_idx, mask);
if (err)
pr_warn("%s: RMAP update failed (%d)\n",
__func__, err);
}
+#endif
}
+#ifdef CONFIG_RFS_ACCEL
static void netif_napi_affinity_release(struct kref *ref)
{
struct napi_struct *napi =
@@ -6901,7 +6908,7 @@ static int napi_irq_cpu_rmap_add(struct napi_struct
*napi, int irq)
if (!rmap)
return -EINVAL;
- napi->notify.notify = netif_irq_cpu_rmap_notify;
+ napi->notify.notify = netif_napi_irq_notify;
napi->notify.release = netif_napi_affinity_release;
cpu_rmap_get(rmap);
rc = cpu_rmap_add(rmap, napi);
@@ -6956,6 +6963,10 @@ static void netif_disable_cpu_rmap(struct net_device
*dev)
}
#else
+static void netif_napi_affinity_release(struct kref *ref)
+{
+}
+
static int napi_irq_cpu_rmap_add(struct napi_struct *napi, int irq)
{
return 0;
@@ -6976,23 +6987,28 @@ void netif_napi_set_irq_locked(struct napi_struct
*napi, int irq)
{
int rc;
- if (!napi->dev->rx_cpu_rmap_auto)
- goto out;
-
- /* Remove existing rmap entries */
- if (napi->irq != irq && napi->irq > 0)
+ /* Remove existing resources */
+ if ((napi->dev->rx_cpu_rmap_auto || napi->dev->irq_affinity_auto) &&
+ napi->irq > 0 && napi->irq != irq)
irq_set_affinity_notifier(napi->irq, NULL);
- if (irq > 0) {
+ if (irq > 0 && napi->dev->rx_cpu_rmap_auto) {
rc = napi_irq_cpu_rmap_add(napi, irq);
if (rc) {
netdev_warn(napi->dev, "Unable to update ARFS map
(%d)\n",
rc);
netif_disable_cpu_rmap(napi->dev);
}
+ } else if (irq > 0 && napi->config && napi->dev->irq_affinity_auto) {
+ napi->notify.notify = netif_napi_irq_notify;
+ napi->notify.release = netif_napi_affinity_release;
+
+ rc = irq_set_affinity_notifier(irq, &napi->notify);
+ if (rc)
+ netdev_warn(napi->dev, "Unable to set IRQ notifier
(%d)\n",
+ rc);
}
-out:
napi->irq = irq;
}
EXPORT_SYMBOL(netif_napi_set_irq_locked);
@@ -7002,6 +7018,10 @@ static void napi_restore_config(struct napi_struct *n)
n->defer_hard_irqs = n->config->defer_hard_irqs;
n->gro_flush_timeout = n->config->gro_flush_timeout;
n->irq_suspend_timeout = n->config->irq_suspend_timeout;
+
+ if (n->irq > 0 && n->dev->irq_affinity_auto)
+ irq_set_affinity(n->irq, &n->config->affinity_mask);
+
/* a NAPI ID might be stored in the config, if so use it. if not, use
* napi_hash_add to generate one for us.
*/
@@ -7126,7 +7146,8 @@ void napi_disable_locked(struct napi_struct *n)
else
napi_hash_del(n);
- if (n->irq > 0 && n->dev->rx_cpu_rmap_auto)
+ if (n->irq > 0 &&
+ (n->dev->irq_affinity_auto || n->dev->rx_cpu_rmap_auto))
irq_set_affinity_notifier(n->irq, NULL);
clear_bit(NAPI_STATE_DISABLE, &n->state);
@@ -11585,7 +11606,7 @@ struct net_device *alloc_netdev_mqs(int sizeof_priv,
const char *name,
{
struct net_device *dev;
size_t napi_config_sz;
- unsigned int maxqs;
+ unsigned int maxqs, i, numa;
BUG_ON(strlen(name) >= sizeof(dev->name));
@@ -11681,6 +11702,10 @@ struct net_device *alloc_netdev_mqs(int sizeof_priv,
const char *name,
dev->napi_config = kvzalloc(napi_config_sz, GFP_KERNEL_ACCOUNT);
if (!dev->napi_config)
goto free_all;
+ numa = dev_to_node(&dev->dev);
+ for (i = 0; i < maxqs; i++)
+ cpumask_set_cpu(cpumask_local_spread(i, numa),
+ &dev->napi_config[i].affinity_mask);
strscpy(dev->name, name);
dev->name_assign_type = name_assign_type;
--
2.43.0
