Re: [PATCH v1 net-next 1/5] drop_monitor: import netnamespace framework
From: Neil Horman <nhorman@tuxdriver.com>
Date: 2017-07-12 13:38:08
On Wed, Jul 12, 2017 at 06:40:49PM +0800, martinbj2008@gmail.com wrote:
From: martin Zhang <redacted> 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 <redacted> --- 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
quoted hunk ↗ jump to hunk
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