pktgen: allow faster module unload
Unloading pktgen module needs ~6 seconds on a 64 cpus machine, to stop
64 kthreads.
Add a pktgen_exiting variable to let kernel threads die faster, so that
kthread_stop() doesnt have to wait too long for them. This variable is
not tested in fast path.
Note : Before exiting from pktgen_thread_worker(), we must make sure
kthread_stop() is waiting for this thread to be stopped, like its done
in kernel/softirq.c
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/pktgen.c b/net/core/pktgen.c
index 52fc1e0..2e57830 100644
--- a/net/core/pktgen.c
+++ b/net/core/pktgen.c
@@ -395,6 +395,8 @@
__be32 tv_usec;
};
+static bool pktgen_exiting __read_mostly;
+
struct pktgen_thread {
spinlock_t if_lock; /* for list of devices */
struct list_head if_list; /* All device here */
@@ -3451,11 +3453,6 @@
remove_proc_entry(t->tsk->comm, pg_proc_dir);
- mutex_lock(&pktgen_thread_lock);
-
- list_del(&t->th_list);
-
- mutex_unlock(&pktgen_thread_lock);
}
static void pktgen_resched(struct pktgen_dev *pkt_dev)
@@ -3602,6 +3599,8 @@
pkt_dev = next_to_run(t);
if (unlikely(!pkt_dev && t->control == 0)) {
+ if (pktgen_exiting)
+ break;
wait_event_interruptible_timeout(t->queue,
t->control != 0,
HZ/10);
@@ -3654,6 +3653,13 @@
pr_debug("%s removing thread\n", t->tsk->comm);
pktgen_rem_thread(t);
+ /* Wait for kthread_stop */
+ while (!kthread_should_stop()) {
+ set_current_state(TASK_INTERRUPTIBLE);
+ schedule();
+ }
+ __set_current_state(TASK_RUNNING);
+
return 0;
}
@@ -3928,6 +3934,7 @@
struct list_head *q, *n;
/* Stop all interfaces & threads */
+ pktgen_exiting = true;
list_for_each_safe(q, n, &pktgen_threads) {
t = list_entry(q, struct pktgen_thread, th_list);
