From: Antonio Quartulli a@unstable.cc
To ensure that no more than one tp_meter session runs at the same time, use an ordered workqueue instead of spawning one kthread per session.
Signed-off-by: Antonio Quartulli a@unstable.cc --- net/batman-adv/main.c | 10 ++++-- net/batman-adv/tp_meter.c | 73 ++++++++++++++++++--------------------- net/batman-adv/tp_meter.h | 3 +- net/batman-adv/types.h | 5 ++- 4 files changed, 48 insertions(+), 43 deletions(-)
diff --git a/net/batman-adv/main.c b/net/batman-adv/main.c index 69c0d85b..cd3f1924 100644 --- a/net/batman-adv/main.c +++ b/net/batman-adv/main.c @@ -91,6 +91,10 @@ static int __init batadv_init(void) if (ret < 0) return ret;
+ ret = batadv_tp_meter_init(); + if (ret < 0) + goto err_tp_meter; + INIT_LIST_HEAD(&batadv_hardif_list); batadv_algo_init();
@@ -99,7 +103,6 @@ static int __init batadv_init(void) batadv_v_init(); batadv_iv_init(); batadv_nc_init(); - batadv_tp_meter_init();
batadv_event_workqueue = create_singlethread_workqueue("bat_events"); if (!batadv_event_workqueue) @@ -118,9 +121,11 @@ static int __init batadv_init(void) return 0;
err_create_wq: + batadv_tp_meter_destroy(); +err_tp_meter: batadv_tt_cache_destroy();
- return -ENOMEM; + return ret; }
static void __exit batadv_exit(void) @@ -138,6 +143,7 @@ static void __exit batadv_exit(void) rcu_barrier();
batadv_tt_cache_destroy(); + batadv_tp_meter_destroy(); }
/** diff --git a/net/batman-adv/tp_meter.c b/net/batman-adv/tp_meter.c index 11520de9..55e93abc 100644 --- a/net/batman-adv/tp_meter.c +++ b/net/batman-adv/tp_meter.c @@ -32,7 +32,6 @@ #include <linux/jiffies.h> #include <linux/kernel.h> #include <linux/kref.h> -#include <linux/kthread.h> #include <linux/list.h> #include <linux/netdevice.h> #include <linux/param.h> @@ -97,6 +96,9 @@
static u8 batadv_tp_prerandom[4096] __read_mostly;
+/* ordered work queue */ +static struct workqueue_struct *batadv_tp_meter_queue; + /** * batadv_tp_session_cookie() - generate session cookie based on session ids * @session: TP session identifier @@ -812,15 +814,18 @@ static int batadv_tp_wait_available(struct batadv_tp_vars *tp_vars, size_t plen) * * Return: nothing, this function never returns */ -static int batadv_tp_send(void *arg) +static void batadv_tp_send(struct work_struct *work) { - struct batadv_tp_vars *tp_vars = arg; - struct batadv_priv *bat_priv = tp_vars->bat_priv; struct batadv_hard_iface *primary_if = NULL; struct batadv_orig_node *orig_node = NULL; + struct batadv_tp_vars *tp_vars; size_t payload_len, packet_len; + struct batadv_priv *bat_priv; int err = 0;
+ tp_vars = container_of(work, struct batadv_tp_vars, test_work); + bat_priv = tp_vars->bat_priv; + if (unlikely(tp_vars->role != BATADV_TP_SENDER)) { err = BATADV_TP_REASON_DST_UNREACHABLE; tp_vars->reason = err; @@ -901,40 +906,17 @@ static int batadv_tp_send(void *arg) batadv_tp_sender_cleanup(bat_priv, tp_vars);
batadv_tp_vars_put(tp_vars); - - do_exit(0); }
/** - * batadv_tp_start_kthread() - start new thread which manages the tp meter - * sender + * batadv_tp_start_work - start new thread which manages the tp meter sender * @tp_vars: the private data of the current TP meter session */ -static void batadv_tp_start_kthread(struct batadv_tp_vars *tp_vars) +static void batadv_tp_start_work(struct batadv_tp_vars *tp_vars) { - struct task_struct *kthread; - struct batadv_priv *bat_priv = tp_vars->bat_priv; - u32 session_cookie; - - kref_get(&tp_vars->refcount); - kthread = kthread_create(batadv_tp_send, tp_vars, "kbatadv_tp_meter"); - if (IS_ERR(kthread)) { - session_cookie = batadv_tp_session_cookie(tp_vars->session, - tp_vars->icmp_uid); - pr_err("batadv: cannot create tp meter kthread\n"); - batadv_tp_batctl_error_notify(BATADV_TP_REASON_MEMORY_ERROR, - tp_vars->other_end, - bat_priv, session_cookie); - - /* drop reserved reference for kthread */ - batadv_tp_vars_put(tp_vars); - - /* cleanup of failed tp meter variables */ - batadv_tp_sender_cleanup(bat_priv, tp_vars); - return; - } - - wake_up_process(kthread); + /* init work item that will actually execute the test and schedule it */ + INIT_WORK(&tp_vars->test_work, batadv_tp_send); + queue_work(batadv_tp_meter_queue, &tp_vars->test_work); }
/** @@ -1053,13 +1035,10 @@ void batadv_tp_start(struct batadv_priv *bat_priv, const u8 *dst, /* init work item for finished tp tests */ INIT_DELAYED_WORK(&tp_vars->finish_work, batadv_tp_sender_finish);
- /* start tp kthread. This way the write() call issued from userspace can - * happily return and avoid to block + /* schedule the tp worker. This way the write() call issued from + * userspace can happily return and avoid to block */ - batadv_tp_start_kthread(tp_vars); - - /* don't return reference to new tp_vars */ - batadv_tp_vars_put(tp_vars); + batadv_tp_start_work(tp_vars); }
/** @@ -1499,7 +1478,23 @@ void batadv_tp_meter_recv(struct batadv_priv *bat_priv, struct sk_buff *skb) /** * batadv_tp_meter_init() - initialize global tp_meter structures */ -void __init batadv_tp_meter_init(void) +int __init batadv_tp_meter_init(void) { get_random_bytes(batadv_tp_prerandom, sizeof(batadv_tp_prerandom)); + + batadv_tp_meter_queue = alloc_ordered_workqueue("bat_tp_meter", 0); + if (!batadv_tp_meter_queue) + return -ENOMEM; + + return 0; +} + +/** + * batadv_tp_meter_destroy() - destroy tp meter memory allocations + */ +void batadv_tp_meter_destroy(void) +{ + flush_workqueue(batadv_tp_meter_queue); + destroy_workqueue(batadv_tp_meter_queue); + batadv_tp_meter_queue = NULL; } diff --git a/net/batman-adv/tp_meter.h b/net/batman-adv/tp_meter.h index 68e60097..ab0bde26 100644 --- a/net/batman-adv/tp_meter.h +++ b/net/batman-adv/tp_meter.h @@ -25,7 +25,8 @@
struct sk_buff;
-void batadv_tp_meter_init(void); +int batadv_tp_meter_init(void); +void batadv_tp_meter_destroy(void); void batadv_tp_start(struct batadv_priv *bat_priv, const u8 *dst, u32 test_length, u32 *cookie); void batadv_tp_stop(struct batadv_priv *bat_priv, const u8 *dst, diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h index 360357f8..c4bc8221 100644 --- a/net/batman-adv/types.h +++ b/net/batman-adv/types.h @@ -1354,7 +1354,10 @@ struct batadv_tp_vars { /** @finish_work: work item for the finishing procedure */ struct delayed_work finish_work;
- /** @test_length: test length in milliseconds */ + /** @test_work: work item for the test process */ + struct work_struct test_work; + + /** @test_length: test length in milliseconds */ u32 test_length;
/** @session: TP session identifier */