for_each_possible_cpu() with a cpu_online() + `thread' check possibly does the job. But there is a tiny race: Say CPU5 is reported online but is going down. And after fcoe_percpu_clean() saw that CPU5 is online it decided to enqueue a packet. After dev_alloc_skb() returned a skb that CPU is offline (or say the notifier destroyed the kthread). So we would OOps because `thread' is NULL. An alternative would be to lock the CPUs during our loop (so no CPU is going away) and then we iterate over the online mask.
Cc: Vasu Dev <[email protected]> Cc: "James E.J. Bottomley" <[email protected]> Cc: "Martin K. Petersen" <[email protected]> Cc: Christoph Hellwig <[email protected]> Cc: [email protected] Cc: [email protected] Signed-off-by: Sebastian Andrzej Siewior <[email protected]> --- drivers/scsi/fcoe/fcoe.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/drivers/scsi/fcoe/fcoe.c b/drivers/scsi/fcoe/fcoe.c index 0efe7112fc1f..2b0d207f4b2b 100644 --- a/drivers/scsi/fcoe/fcoe.c +++ b/drivers/scsi/fcoe/fcoe.c @@ -2461,12 +2461,10 @@ static void fcoe_percpu_clean(struct fc_lport *lport) struct sk_buff *skb; unsigned int cpu; - for_each_possible_cpu(cpu) { + get_online_cpus(); + for_each_online_cpu(cpu) { pp = &per_cpu(fcoe_percpu, cpu); - if (!pp->thread || !cpu_online(cpu)) - continue; - skb = dev_alloc_skb(0); if (!skb) continue; @@ -2481,6 +2479,7 @@ static void fcoe_percpu_clean(struct fc_lport *lport) wait_for_completion(&fcoe_flush_completion); } + put_online_cpus(); } /** -- 2.7.0 _______________________________________________ fcoe-devel mailing list [email protected] http://lists.open-fcoe.org/mailman/listinfo/fcoe-devel
