Re: [Patch bpf-next v4 1/3] bpf: introduce timeout hash map

On Sat, Jan 16, 2021 at 8:22 PM Cong Wang [off-list ref] wrote:

+static void htab_gc(struct work_struct *work)
+{
+       struct htab_elem *e, *tmp;
+       struct llist_node *lhead;
+       struct bpf_htab *htab;
+       int i, count;
+
+       htab = container_of(work, struct bpf_htab, gc_work.work);
+       lhead = llist_del_all(&htab->gc_list);
+
+       llist_for_each_entry_safe(e, tmp, lhead, gc_node) {
+               unsigned long flags;
+               struct bucket *b;
+               u32 hash;
+
+               hash = e->hash;
+               b = __select_bucket(htab, hash);
+               if (htab_lock_bucket(htab, b, hash, &flags))
+                       continue;
+               hlist_nulls_del_rcu(&e->hash_node);
+               atomic_set(&e->pending, 0);
+               free_htab_elem(htab, e);
+               htab_unlock_bucket(htab, b, hash, flags);
+
+               cond_resched();
+       }
+
+       for (count = 0, i = 0; i < htab->n_buckets; i++) {

I just realized a followup fix is not folded into this patch, I
actually added a timestamp check here to avoid scanning the whole
table more frequently than once per second. It is clearly my mistake
to miss it when formatting this patchset.

I will send v5 after waiting for other feedback.

Thanks!