From: Jason Gunthorpe <jgg@nvidia.com>
To: Leon Romanovsky <leon@kernel.org>
Cc: Patrisious Haddad <phaddad@nvidia.com>,
linux-kernel@vger.kernel.org, linux-rdma@vger.kernel.org,
Mark Zhang <markzhang@nvidia.com>
Subject: Re: [PATCH rdma-next 1/2] RDMA/core: Add an rb_tree that stores cm_ids sorted by ifindex and remote IP
Date: Tue, 10 May 2022 20:56:37 -0300 [thread overview]
Message-ID: <20220510235637.GA1163656@nvidia.com> (raw)
In-Reply-To: <9594928bfa8c8996bfdb31bc575c289573fa5bfb.1649075034.git.leonro@nvidia.com>
On Mon, Apr 04, 2022 at 03:27:26PM +0300, Leon Romanovsky wrote:
> +static int compare_netdev_and_ip(int ifindex_a, struct sockaddr *sa,
> + int ifindex_b, struct sockaddr *sb)
> +{
> + if (ifindex_a != ifindex_b)
> + return ifindex_a - ifindex_b;
These subtraction tricks don't work if the value can overflow
INT_MAX - INT_MIN == undefined
> +static int cma_add_id_to_tree(struct rdma_id_private *node_id_priv)
> +{
> + struct rb_node **new = &id_table.rb_node, *parent = NULL;
This read of rb_node has to be under the spinlock
> + struct id_table_entry *this, *node;
> + struct rdma_id_private *id_priv;
> + unsigned long flags;
> + int result;
> +
> + node = kzalloc(sizeof(*node), GFP_KERNEL);
> + if (!node)
> + return -ENOMEM;
> +
> + spin_lock_irqsave(&id_table_lock, flags);
> + while (*new) {
> + this = container_of(*new, struct id_table_entry, rb_node);
Because rebalacing can alter the head
> + id_priv = list_first_entry(
> + &this->id_list, struct rdma_id_private, id_list_entry);
> + result = compare_netdev_and_ip(
> + node_id_priv->id.route.addr.dev_addr.bound_dev_if,
> + cma_dst_addr(node_id_priv),
> + id_priv->id.route.addr.dev_addr.bound_dev_if,
> + cma_dst_addr(id_priv));
This pattern keeps repeating, one of the arguments to compare should
just be the id_table_entry * and do the list_first/etc inside the
compare.
Jason
next prev parent reply other threads:[~2022-05-10 23:56 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-04-04 12:27 [PATCH rdma-next 0/2] Add gratuitous ARP support to RDMA-CM Leon Romanovsky
2022-04-04 12:27 ` [PATCH rdma-next 1/2] RDMA/core: Add an rb_tree that stores cm_ids sorted by ifindex and remote IP Leon Romanovsky
2022-05-10 23:56 ` Jason Gunthorpe [this message]
2022-04-04 12:27 ` [PATCH rdma-next 2/2] RDMA/core: Add a netevent notifier to cma Leon Romanovsky
2022-05-11 0:04 ` Jason Gunthorpe
2022-04-29 16:07 ` [PATCH rdma-next 0/2] Add gratuitous ARP support to RDMA-CM Olga Kornievskaia
2022-04-29 16:23 ` Leon Romanovsky
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