cake_dump_stats() runs without qdisc spinlock being held. In this final patch, I add READ_ONCE()/WRITE_ONCE() annotations for cparams.target and cparams.interval. Fixes: 046f6fd5daef ("sched: Add Common Applications Kept Enhanced (cake) qdisc") Signed-off-by: Eric Dumazet Acked-by: "Toke Høiland-Jørgensen" --- net/sched/sch_cake.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) diff --git a/net/sched/sch_cake.c b/net/sched/sch_cake.c index 975f5d6d6982f33a9d1f5454721ce16b6c433439..13c6d1869a144738c52ffc462f06338bf8245fea 100644 --- a/net/sched/sch_cake.c +++ b/net/sched/sch_cake.c @@ -2356,10 +2356,11 @@ static void cake_set_rate(struct cake_tin_data *b, u64 rate, u32 mtu, byte_target_ns = (byte_target * rate_ns) >> rate_shft; - b->cparams.target = max((byte_target_ns * 3) / 2, target_ns); - b->cparams.interval = max(rtt_est_ns + - b->cparams.target - target_ns, - b->cparams.target * 2); + WRITE_ONCE(b->cparams.target, + max((byte_target_ns * 3) / 2, target_ns)); + WRITE_ONCE(b->cparams.interval, + max(rtt_est_ns + b->cparams.target - target_ns, + b->cparams.target * 2)); b->cparams.mtu_time = byte_target_ns; b->cparams.p_inc = 1 << 24; /* 1/256 */ b->cparams.p_dec = 1 << 20; /* 1/4096 */ @@ -3042,9 +3043,9 @@ static int cake_dump_stats(struct Qdisc *sch, struct gnet_dump *d) PUT_TSTAT_U32(BACKLOG_BYTES, READ_ONCE(b->tin_backlog)); PUT_TSTAT_U32(TARGET_US, - ktime_to_us(ns_to_ktime(b->cparams.target))); + ktime_to_us(ns_to_ktime(READ_ONCE(b->cparams.target)))); PUT_TSTAT_U32(INTERVAL_US, - ktime_to_us(ns_to_ktime(b->cparams.interval))); + ktime_to_us(ns_to_ktime(READ_ONCE(b->cparams.interval)))); PUT_TSTAT_U32(SENT_PACKETS, READ_ONCE(b->packets)); PUT_TSTAT_U32(DROPPED_PACKETS, READ_ONCE(b->tin_dropped)); -- 2.54.0.545.g6539524ca2-goog