Commit 979b581e authored by Eric Dumazet's avatar Eric Dumazet Committed by Jakub Kicinski
Browse files

pktgen: use cpus_read_lock() in pg_net_init() 



I have seen the WARN_ON(smp_processor_id() != cpu) firing
in pktgen_thread_worker() during tests.

We must use cpus_read_lock()/cpus_read_unlock()
around the for_each_online_cpu(cpu) loop.

While we are at it use WARN_ON_ONCE() to avoid a possible syslog flood.

Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20240821175339.1191779-1-edumazet@google.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent aa0743a2

net/core/pktgen.c

+3 −1
Original line number Diff line number Diff line
@@ -3654,7 +3654,7 @@ static int pktgen_thread_worker(void *arg) 
	struct pktgen_dev *pkt_dev = NULL;

	int cpu = t->cpu;



	WARN_ON(smp_processor_id() != cpu);

	WARN_ON_ONCE(smp_processor_id() != cpu);



	init_waitqueue_head(&t->queue);

	complete(&t->start_done);
@@ -3989,6 +3989,7 @@ static int __net_init pg_net_init(struct net *net) 
		goto remove;

	}



	cpus_read_lock();

	for_each_online_cpu(cpu) {

		int err;
@@ -3997,6 +3998,7 @@ static int __net_init pg_net_init(struct net *net) 
			pr_warn("Cannot create thread for cpu %d (%d)\n",

				   cpu, err);

	}

	cpus_read_unlock();



	if (list_empty(&pn->pktgen_threads)) {

		pr_err("Initialization failed for all threads\n");