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    SubjectRe: [PATCH v1 3/3] net: WireGuard secure network tunnel
    On Tue, 31 Jul 2018 21:11:02 +0200
    "Jason A. Donenfeld" <Jason@zx2c4.com> wrote:

    > +#define push(stack, p, len) ({ \
    > + if (rcu_access_pointer(p)) { \
    > + BUG_ON(len >= 128); \
    > + stack[len++] = rcu_dereference_protected(p, lockdep_is_held(lock)); \
    > + } \
    > + true; \
    > +})
    > +static void free_root_node(struct allowedips_node __rcu *top, struct mutex *lock)
    > +{
    > + struct allowedips_node *stack[128], *node;
    > + unsigned int len;
    > +
    > + for (len = 0, push(stack, top, len); len > 0 && (node = stack[--len]) && push(stack, node->bit[0], len) && push(stack, node->bit[1], len);)
    > + call_rcu_bh(&node->rcu, node_free_rcu);
    > +}

    This looks like you are doing traversal to free a tree. The stack is there so that you do the rcu callbacks
    in the proper order. Won't this create an lot of RCU work at once?

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      Last update: 2018-07-31 22:27    [W:3.965 / U:0.028 seconds]
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