diff options
| -rw-r--r-- | net/sched/sch_cake.c | 131 |
1 files changed, 71 insertions, 60 deletions
diff --git a/net/sched/sch_cake.c b/net/sched/sch_cake.c index 806eb73d6a05..5862933be8d7 100644 --- a/net/sched/sch_cake.c +++ b/net/sched/sch_cake.c @@ -399,14 +399,14 @@ static void cake_configure_rates(struct Qdisc *sch, u64 rate, bool rate_adjust); * Here, invsqrt is a fixed point number (< 1.0), 32bit mantissa, aka Q0.32 */ -static void cobalt_newton_step(struct cobalt_vars *vars) +static void cobalt_newton_step(struct cobalt_vars *vars, u32 count) { u32 invsqrt, invsqrt2; u64 val; invsqrt = vars->rec_inv_sqrt; invsqrt2 = ((u64)invsqrt * invsqrt) >> 32; - val = (3LL << 32) - ((u64)vars->count * invsqrt2); + val = (3LL << 32) - ((u64)count * invsqrt2); val >>= 2; /* avoid overflow in following multiply */ val = (val * invsqrt) >> (32 - 2 + 1); @@ -414,12 +414,12 @@ static void cobalt_newton_step(struct cobalt_vars *vars) vars->rec_inv_sqrt = val; } -static void cobalt_invsqrt(struct cobalt_vars *vars) +static void cobalt_invsqrt(struct cobalt_vars *vars, u32 count) { - if (vars->count < REC_INV_SQRT_CACHE) - vars->rec_inv_sqrt = inv_sqrt_cache[vars->count]; + if (count < REC_INV_SQRT_CACHE) + vars->rec_inv_sqrt = inv_sqrt_cache[count]; else - cobalt_newton_step(vars); + cobalt_newton_step(vars, count); } static void cobalt_vars_init(struct cobalt_vars *vars) @@ -449,16 +449,19 @@ static bool cobalt_queue_full(struct cobalt_vars *vars, bool up = false; if (ktime_to_ns(ktime_sub(now, vars->blue_timer)) > p->target) { - up = !vars->p_drop; - vars->p_drop += p->p_inc; - if (vars->p_drop < p->p_inc) - vars->p_drop = ~0; - vars->blue_timer = now; - } - vars->dropping = true; - vars->drop_next = now; + u32 p_drop = vars->p_drop; + + up = !p_drop; + p_drop += p->p_inc; + if (p_drop < p->p_inc) + p_drop = ~0; + WRITE_ONCE(vars->p_drop, p_drop); + WRITE_ONCE(vars->blue_timer, now); + } + WRITE_ONCE(vars->dropping, true); + WRITE_ONCE(vars->drop_next, now); if (!vars->count) - vars->count = 1; + WRITE_ONCE(vars->count, 1); return up; } @@ -475,20 +478,20 @@ static bool cobalt_queue_empty(struct cobalt_vars *vars, if (vars->p_drop && ktime_to_ns(ktime_sub(now, vars->blue_timer)) > p->target) { if (vars->p_drop < p->p_dec) - vars->p_drop = 0; + WRITE_ONCE(vars->p_drop, 0); else - vars->p_drop -= p->p_dec; - vars->blue_timer = now; + WRITE_ONCE(vars->p_drop, vars->p_drop - p->p_dec); + WRITE_ONCE(vars->blue_timer, now); down = !vars->p_drop; } - vars->dropping = false; + WRITE_ONCE(vars->dropping, false); if (vars->count && ktime_to_ns(ktime_sub(now, vars->drop_next)) >= 0) { - vars->count--; - cobalt_invsqrt(vars); - vars->drop_next = cobalt_control(vars->drop_next, - p->interval, - vars->rec_inv_sqrt); + WRITE_ONCE(vars->count, vars->count - 1); + cobalt_invsqrt(vars, vars->count); + WRITE_ONCE(vars->drop_next, + cobalt_control(vars->drop_next, p->interval, + vars->rec_inv_sqrt)); } return down; @@ -507,6 +510,7 @@ static enum qdisc_drop_reason cobalt_should_drop(struct cobalt_vars *vars, bool next_due, over_target; ktime_t schedule; u64 sojourn; + u32 count; /* The 'schedule' variable records, in its sign, whether 'now' is before or * after 'drop_next'. This allows 'drop_next' to be updated before the next @@ -528,21 +532,22 @@ static enum qdisc_drop_reason cobalt_should_drop(struct cobalt_vars *vars, over_target = sojourn > p->target && sojourn > p->mtu_time * bulk_flows * 2 && sojourn > p->mtu_time * 4; - next_due = vars->count && ktime_to_ns(schedule) >= 0; + count = vars->count; + next_due = count && ktime_to_ns(schedule) >= 0; vars->ecn_marked = false; if (over_target) { if (!vars->dropping) { - vars->dropping = true; - vars->drop_next = cobalt_control(now, - p->interval, - vars->rec_inv_sqrt); + WRITE_ONCE(vars->dropping, true); + WRITE_ONCE(vars->drop_next, + cobalt_control(now, p->interval, + vars->rec_inv_sqrt)); } - if (!vars->count) - vars->count = 1; + if (!count) + count = 1; } else if (vars->dropping) { - vars->dropping = false; + WRITE_ONCE(vars->dropping, false); } if (next_due && vars->dropping) { @@ -550,23 +555,23 @@ static enum qdisc_drop_reason cobalt_should_drop(struct cobalt_vars *vars, if (!(vars->ecn_marked = INET_ECN_set_ce(skb))) reason = QDISC_DROP_CONGESTED; - vars->count++; - if (!vars->count) - vars->count--; - cobalt_invsqrt(vars); - vars->drop_next = cobalt_control(vars->drop_next, - p->interval, - vars->rec_inv_sqrt); + count++; + if (!count) + count--; + cobalt_invsqrt(vars, count); + WRITE_ONCE(vars->drop_next, + cobalt_control(vars->drop_next, p->interval, + vars->rec_inv_sqrt)); schedule = ktime_sub(now, vars->drop_next); } else { while (next_due) { - vars->count--; - cobalt_invsqrt(vars); - vars->drop_next = cobalt_control(vars->drop_next, - p->interval, - vars->rec_inv_sqrt); + count--; + cobalt_invsqrt(vars, count); + WRITE_ONCE(vars->drop_next, + cobalt_control(vars->drop_next, p->interval, + vars->rec_inv_sqrt)); schedule = ktime_sub(now, vars->drop_next); - next_due = vars->count && ktime_to_ns(schedule) >= 0; + next_due = count && ktime_to_ns(schedule) >= 0; } } @@ -575,11 +580,12 @@ static enum qdisc_drop_reason cobalt_should_drop(struct cobalt_vars *vars, get_random_u32() < vars->p_drop) reason = QDISC_DROP_FLOOD_PROTECTION; + WRITE_ONCE(vars->count, count); /* Overload the drop_next field as an activity timeout */ - if (!vars->count) - vars->drop_next = ktime_add_ns(now, p->interval); + if (!count) + WRITE_ONCE(vars->drop_next, ktime_add_ns(now, p->interval)); else if (ktime_to_ns(schedule) > 0 && reason == QDISC_DROP_UNSPEC) - vars->drop_next = now; + WRITE_ONCE(vars->drop_next, now); return reason; } @@ -1924,7 +1930,7 @@ static s32 cake_enqueue(struct sk_buff *skb, struct Qdisc *sch, flow->set = CAKE_SET_SPARSE; WRITE_ONCE(b->sparse_flow_count, b->sparse_flow_count + 1); - flow->deficit = cake_get_flow_quantum(b, flow, q->config->flow_mode); + WRITE_ONCE(flow->deficit, cake_get_flow_quantum(b, flow, q->config->flow_mode)); } else if (flow->set == CAKE_SET_SPARSE_WAIT) { /* this flow was empty, accounted as a sparse flow, but actually * in the bulk rotation. @@ -2166,7 +2172,8 @@ retry: } } - flow->deficit += cake_get_flow_quantum(b, flow, q->config->flow_mode); + WRITE_ONCE(flow->deficit, + flow->deficit + cake_get_flow_quantum(b, flow, q->config->flow_mode)); list_move_tail(&flow->flowchain, &b->old_flows); goto retry; @@ -2232,7 +2239,7 @@ retry: if (q->config->rate_flags & CAKE_FLAG_INGRESS) { len = cake_advance_shaper(q, b, skb, now, true); - flow->deficit -= len; + WRITE_ONCE(flow->deficit, flow->deficit - len); b->tin_deficit -= len; } WRITE_ONCE(flow->dropped, flow->dropped + 1); @@ -2259,7 +2266,7 @@ retry: delay < b->base_delay ? 2 : 8)); len = cake_advance_shaper(q, b, skb, now, false); - flow->deficit -= len; + WRITE_ONCE(flow->deficit, flow->deficit - len); b->tin_deficit -= len; if (ktime_after(q->time_next_packet, now) && sch->q.qlen) { @@ -3153,6 +3160,8 @@ static int cake_dump_class_stats(struct Qdisc *sch, unsigned long cl, return -1; if (flow) { ktime_t now = ktime_get(); + bool dropping; + u32 p_drop; stats = nla_nest_start_noflag(d->skb, TCA_STATS_APP); if (!stats) @@ -3167,21 +3176,23 @@ static int cake_dump_class_stats(struct Qdisc *sch, unsigned long cl, goto nla_put_failure; \ } while (0) - PUT_STAT_S32(DEFICIT, flow->deficit); - PUT_STAT_U32(DROPPING, flow->cvars.dropping); - PUT_STAT_U32(COBALT_COUNT, flow->cvars.count); - PUT_STAT_U32(P_DROP, flow->cvars.p_drop); - if (flow->cvars.p_drop) { + PUT_STAT_S32(DEFICIT, READ_ONCE(flow->deficit)); + dropping = READ_ONCE(flow->cvars.dropping); + PUT_STAT_U32(DROPPING, dropping); + PUT_STAT_U32(COBALT_COUNT, READ_ONCE(flow->cvars.count)); + p_drop = READ_ONCE(flow->cvars.p_drop); + PUT_STAT_U32(P_DROP, p_drop); + if (p_drop) { PUT_STAT_S32(BLUE_TIMER_US, ktime_to_us( ktime_sub(now, - flow->cvars.blue_timer))); + READ_ONCE(flow->cvars.blue_timer)))); } - if (flow->cvars.dropping) { + if (dropping) { PUT_STAT_S32(DROP_NEXT_US, ktime_to_us( ktime_sub(now, - flow->cvars.drop_next))); + READ_ONCE(flow->cvars.drop_next)))); } if (nla_nest_end(d->skb, stats) < 0) |