On Wed, Jul 12, 2017 at 06:40:49PM +0800, martinbj2...@gmail.com wrote:
> From: martin Zhang <zhangjunweimar...@didichuxing.com>
>
> This is a serial patch for drop monitor, in order to support net namespace.
>
> Import two struct to support net ns:
>
> 1. struct per_ns_dm_cb:
> Just like its name, it is used in per net ns.
>
> In this patch it is empty, but in following patch, these field will be
> added.
> a. trace_state: every net ns has a switch to indicate the trace state.
> b. ns_dm_mutex: the mutex will only work and keep exclusive operatons in a
> net ns.
> c. hw_stats_list: monitor for NAPI of net device.
>
> 2. ns_pcpu_dm_data
> It is used to replace per_cpu_dm_data under per net ns.
>
> per_cpu_dm_data will only keep the dm_alert_work, and the other field
> will be moved to ns_pcpu_dm_data. They do same thing just like current
> code, and the only difference is under per net ns.
>
> Keep there is a work under percpu, to send alter netlink message.
>
> Signed-off-by: martin Zhang <zhangjunweimar...@didichuxing.com>
> ---
> The dropwatch is a very useful tool to diagnose network problem,
> which give us greate help.
> Dropwatch could not work under container(net namespace).
> It is a pitty, so let it support net ns.
>
Sorry, Im having a hard time wrapping my head around this. Why exactly is it
that dropwatch won't work in a namespaced environment? IIRC, the kfree
tracepoints are namespace agnostic, and so running dropwatch anywhere should
result in seeing drops in all namespaces. I grant that perhaps it would be nice
to filter on a namespace, but it should all 'just work' for some definition of
the term, no?
Neil
> net/core/drop_monitor.c | 41 +++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 41 insertions(+)
>
> diff --git a/net/core/drop_monitor.c b/net/core/drop_monitor.c
> index 70ccda2..6a75e04 100644
> --- a/net/core/drop_monitor.c
> +++ b/net/core/drop_monitor.c
> @@ -32,6 +32,10 @@
> #include <trace/events/napi.h>
>
> #include <asm/unaligned.h>
> +#include <net/sock.h>
> +#include <net/net_namespace.h>
> +#include <net/netns/generic.h>
> +#include <linux/smp.h>
>
> #define TRACE_ON 1
> #define TRACE_OFF 0
> @@ -41,6 +45,13 @@
> * and the work handle that will send up
> * netlink alerts
> */
> +
> +struct ns_pcpu_dm_data {
> +};
> +
> +struct per_ns_dm_cb {
> +};
> +
> static int trace_state = TRACE_OFF;
> static DEFINE_MUTEX(trace_state_mutex);
>
> @@ -59,6 +70,7 @@ struct dm_hw_stat_delta {
> unsigned long last_drop_val;
> };
>
> +static int dm_net_id __read_mostly;
> static struct genl_family net_drop_monitor_family;
>
> static DEFINE_PER_CPU(struct per_cpu_dm_data, dm_cpu_data);
> @@ -382,6 +394,33 @@ static int dropmon_net_event(struct notifier_block
> *ev_block,
> .notifier_call = dropmon_net_event
> };
>
> +static int __net_init dm_net_init(struct net *net)
> +{
> + struct per_ns_dm_cb *ns_dm_cb;
> +
> + ns_dm_cb = net_generic(net, dm_net_id);
> + if (!ns_dm_cb)
> + return -ENOMEM;
> +
> + return 0;
> +}
> +
> +static void __net_exit dm_net_exit(struct net *net)
> +{
> + struct per_ns_dm_cb *ns_dm_cb;
> +
> + ns_dm_cb = net_generic(net, dm_net_id);
> + if (!ns_dm_cb)
> + return;
> +}
> +
> +static struct pernet_operations dm_net_ops = {
> + .init = dm_net_init,
> + .exit = dm_net_exit,
> + .id = &dm_net_id,
> + .size = sizeof(struct per_ns_dm_cb),
> +};
> +
> static int __init init_net_drop_monitor(void)
> {
> struct per_cpu_dm_data *data;
> @@ -393,6 +432,7 @@ static int __init init_net_drop_monitor(void)
> pr_err("Unable to store program counters on this arch, Drop
> monitor failed\n");
> return -ENOSPC;
> }
> + rc = register_pernet_subsys(&dm_net_ops);
>
> rc = genl_register_family(&net_drop_monitor_family);
> if (rc) {
> @@ -441,6 +481,7 @@ static void exit_net_drop_monitor(void)
> * or pending schedule calls
> */
>
> + unregister_pernet_subsys(&dm_net_ops);
> for_each_possible_cpu(cpu) {
> data = &per_cpu(dm_cpu_data, cpu);
> del_timer_sync(&data->send_timer);
> --
> 1.8.3.1
>
>
