[PATCH net-next 04/10] netdevsim: Allow reporting activity on nexthop buckets
From: Petr Machata <petrm@nvidia.com>
Date: 2021-03-12 16:52:23
Subsystem:
netdevsim, networking drivers, the rest · Maintainers:
Jakub Kicinski, Andrew Lunn, "David S. Miller", Eric Dumazet, Paolo Abeni, Linus Torvalds
From: Ido Schimmel <idosch@nvidia.com> A key component of the resilient hashing algorithm is the hash buckets' activity. If a bucket is active, it will not be populated with a new nexthop in order not to break existing flows. Therefore, in order to easily and thoroughly test the algorithm, we need to be in full control over the reported activity. Add a debugfs interface that allows user space to have netdevsim report a nexthop bucket within a resilient nexthop group as active. For example: # echo 10 23 > /sys/kernel/debug/netdevsim/netdevsim10/fib/nexthop_bucket_activity Will mark bucket 23 in nexthop group 10 as active. Signed-off-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: Petr Machata <petrm@nvidia.com> Signed-off-by: Petr Machata <petrm@nvidia.com> --- drivers/net/netdevsim/fib.c | 61 +++++++++++++++++++++++++++++++++++++ 1 file changed, 61 insertions(+)
diff --git a/drivers/net/netdevsim/fib.c b/drivers/net/netdevsim/fib.c
index e41f3b98295c..fda6f37e7055 100644
--- a/drivers/net/netdevsim/fib.c
+++ b/drivers/net/netdevsim/fib.c@@ -14,6 +14,7 @@ * THE COST OF ALL NECESSARY SERVICING, REPAIR OR CORRECTION. */ +#include <linux/bitmap.h> #include <linux/in6.h> #include <linux/kernel.h> #include <linux/list.h>
@@ -1345,6 +1346,63 @@ static void nsim_nexthop_free(void *ptr, void *arg) nsim_nexthop_destroy(nexthop); } +static ssize_t nsim_nexthop_bucket_activity_write(struct file *file, + const char __user *user_buf, + size_t size, loff_t *ppos) +{ + struct nsim_fib_data *data = file->private_data; + struct net *net = devlink_net(data->devlink); + struct nsim_nexthop *nexthop; + unsigned long *activity; + loff_t pos = *ppos; + u16 bucket_index; + char buf[128]; + int err = 0; + u32 nhid; + + if (pos != 0) + return -EINVAL; + if (size > sizeof(buf)) + return -EINVAL; + if (copy_from_user(buf, user_buf, size)) + return -EFAULT; + if (sscanf(buf, "%u %hu", &nhid, &bucket_index) != 2) + return -EINVAL; + + rtnl_lock(); + + nexthop = rhashtable_lookup_fast(&data->nexthop_ht, &nhid, + nsim_nexthop_ht_params); + if (!nexthop || !nexthop->is_resilient || + bucket_index >= nexthop->occ) { + err = -EINVAL; + goto out; + } + + activity = bitmap_zalloc(nexthop->occ, GFP_KERNEL); + if (!activity) { + err = -ENOMEM; + goto out; + } + + bitmap_set(activity, bucket_index, 1); + nexthop_res_grp_activity_update(net, nhid, nexthop->occ, activity); + bitmap_free(activity); + +out: + rtnl_unlock(); + + *ppos = size; + return err ?: size; +} + +static const struct file_operations nsim_nexthop_bucket_activity_fops = { + .open = simple_open, + .write = nsim_nexthop_bucket_activity_write, + .llseek = no_llseek, + .owner = THIS_MODULE, +}; + static u64 nsim_fib_ipv4_resource_occ_get(void *priv) { struct nsim_fib_data *data = priv;
@@ -1442,6 +1500,9 @@ nsim_fib_debugfs_init(struct nsim_fib_data *data, struct nsim_dev *nsim_dev) data->fail_nexthop_bucket_replace = false; debugfs_create_bool("fail_nexthop_bucket_replace", 0600, data->ddir, &data->fail_nexthop_bucket_replace); + + debugfs_create_file("nexthop_bucket_activity", 0200, data->ddir, + data, &nsim_nexthop_bucket_activity_fops); return 0; }
--
2.26.2