2018-01-10 16:43:43

by Benjamin Beichler

Subject: [PATCH v3 1/5] mac80211_hwsim: add workqueue to wait for deferred radio deletion on mod unload

When closing multiple wmediumd instances with many radios and try to
unload the mac80211_hwsim module, it may happen that the work items live
longer than the module. To wait especially for this deletion work items,
add a work queue, otherwise flush_scheduled_work would be necessary.

Signed-off-by: Benjamin Beichler <[email protected]>
---
drivers/net/wireless/mac80211_hwsim.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/mac80211_hwsim.c b/drivers/net/wireless/mac80211_hwsim.c
index 45cca54c05bf..742a1551bb1c 100644
--- a/drivers/net/wireless/mac80211_hwsim.c
+++ b/drivers/net/wireless/mac80211_hwsim.c
@@ -489,6 +489,7 @@ static const struct ieee80211_iface_combination hwsim_if_comb_p2p_dev[] = {

static spinlock_t hwsim_radio_lock;
static LIST_HEAD(hwsim_radios);
+static struct workqueue_struct *hwsim_wq;
static int hwsim_radio_idx;

static struct platform_driver mac80211_hwsim_driver = {
@@ -3346,7 +3347,7 @@ static void remove_user_radios(u32 portid)
if (entry->destroy_on_close && entry->portid == portid) {
list_del(&entry->list);
INIT_WORK(&entry->destroy_work, destroy_radio);
- schedule_work(&entry->destroy_work);
+ queue_work(hwsim_wq, &entry->destroy_work);
}
}
spin_unlock_bh(&hwsim_radio_lock);
@@ -3421,7 +3422,7 @@ static void __net_exit hwsim_exit_net(struct net *net)

list_del(&data->list);
INIT_WORK(&data->destroy_work, destroy_radio);
- schedule_work(&data->destroy_work);
+ queue_work(hwsim_wq, &data->destroy_work);
}
spin_unlock_bh(&hwsim_radio_lock);
}
@@ -3453,6 +3454,10 @@ static int __init init_mac80211_hwsim(void)

spin_lock_init(&hwsim_radio_lock);

+ hwsim_wq = alloc_workqueue("hwsim_wq",WQ_MEM_RECLAIM,0);
+ if (!hwsim_wq)
+ return -ENOMEM;
+
err = register_pernet_device(&hwsim_net_ops);
if (err)
return err;
@@ -3591,8 +3596,11 @@ static void __exit exit_mac80211_hwsim(void)
hwsim_exit_netlink();

mac80211_hwsim_free();
+ flush_workqueue(hwsim_wq);
+
unregister_netdev(hwsim_mon);
platform_driver_unregister(&mac80211_hwsim_driver);
unregister_pernet_device(&hwsim_net_ops);
+ destroy_workqueue(hwsim_wq);
}
module_exit(exit_mac80211_hwsim);
--
2.15.1

2018-01-15 11:46:07

by Johannes Berg

Subject: Re: [PATCH v3 1/5] mac80211_hwsim: add workqueue to wait for deferred radio deletion on mod unload

On Wed, 2018-01-10 at 17:42 +0100, Benjamin Beichler wrote:
> When closing multiple wmediumd instances with many radios and try to
> unload the mac80211_hwsim module, it may happen that the work items live
> longer than the module. To wait especially for this deletion work items,
> add a work queue, otherwise flush_scheduled_work would be necessary.
>
Applied this to mac80211, thanks.

johannes