On 2025-01-20 5:59 p.m., Jakub Kicinski wrote:
On Fri, 17 Jan 2025 17:33:31 -0700 Ahmed Zaki wrote:
+#ifdef CONFIG_RFS_ACCEL
+static void
+netif_irq_cpu_rmap_notify(struct irq_affinity_notify *notify,
+ const cpumask_t *mask)
+{
+ struct napi_struct *napi =
+ container_of(notify, struct napi_struct, notify);
+ struct cpu_rmap *rmap = napi->dev->rx_cpu_rmap;
+ int err;
+
+ if (napi->dev->rx_cpu_rmap_auto) {
Can this ever not be true?
It can, but not in this patch. I will it move to next one.
+ err = cpu_rmap_update(rmap, napi->napi_rmap_idx, mask);
+ if (err)
+ pr_warn("%s: RMAP update failed (%d)\n",
+ __func__, err);
netdev_warn(napi->dev, "...) ?
+ }
+}
+
+static void netif_napi_affinity_release(struct kref *ref)
+{
+ struct napi_struct *napi =
+ container_of(ref, struct napi_struct, notify.kref);
+ struct cpu_rmap *rmap = napi->dev->rx_cpu_rmap;
+
+ if (!napi->dev->rx_cpu_rmap_auto)
Similar question, can it possibly be false without driver bugs?
I think you disable rmap completely if we can't add a single IRQ,
that may be too drastic. Better miss one IRQ than the whole rmap, no?
Same. This belongs to next patch (when the notifier can be set because
of ARFS rmap or napi.irq affinity).
+ return;
+ rmap->obj[napi->napi_rmap_idx] = NULL;
+ napi->napi_rmap_idx = -1;
Why do we modify NAPI here? Shouldn't caller be responsible for this?
This is called when the notifier is set to NULL.
Setting napi_rmap_idx is not strictly needed but the idea was to have
netif_napi_affinity_release() unwind all changes made in
napi_irq_cpu_rmap_add().
