| Message ID | 20200918084252.4200-1-yanxiaoyong5@gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | net/sched: cbs: fix calculation error of idleslope credits | expand |
From: Xiaoyong Yan <yanxiaoyong5@gmail.com> Date: Fri, 18 Sep 2020 01:42:52 -0700 > + delay = delay_from_credits(q->credits, q->idleslope); > + cbs_timer_schedule(q, now+ delay); > + q->last = now; This indentation cannot be correct. Please fix this.
Hi Xiaoyong,
Thank you for the patch! Perhaps something to improve:
[auto build test WARNING on linus/master]
[also build test WARNING on v5.9-rc5 next-20200918]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]
url: https://github.com/0day-ci/linux/commits/Xiaoyong-Yan/net-sched-cbs-fix-calculation-error-of-idleslope-credits/20200918-164430
base: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 10b82d5176488acee2820e5a2cf0f2ec5c3488b6
config: h8300-randconfig-m031-20200917 (attached as .config)
compiler: h8300-linux-gcc (GCC) 9.3.0
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>
smatch warnings:
net/sched/sch_cbs.c:224 cbs_dequeue_soft() warn: inconsistent indenting
# https://github.com/0day-ci/linux/commit/6e3656a6f5879070aaee0343f90e633de7d2d85a
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review Xiaoyong-Yan/net-sched-cbs-fix-calculation-error-of-idleslope-credits/20200918-164430
git checkout 6e3656a6f5879070aaee0343f90e633de7d2d85a
vim +224 net/sched/sch_cbs.c
205
206 static struct sk_buff *cbs_dequeue_soft(struct Qdisc *sch)
207 {
208 struct cbs_sched_data *q = qdisc_priv(sch);
209 struct Qdisc *qdisc = q->qdisc;
210 s64 now = ktime_get_ns();
211 struct sk_buff *skb;
212 s64 credits;
213 int len;
214
215 /* The previous packet is still being sent */
216 if (now < q->last) {
217 cbs_timer_schedule(q, q->last);
218 return NULL;
219 }
220 if (q->credits < 0) {
221 s64 delay;
222
223 delay = delay_from_credits(q->credits, q->idleslope);
> 224 cbs_timer_schedule(q, now+ delay);
225 q->last = now;
226
227 return NULL;
228 }
229 skb = cbs_child_dequeue(sch, qdisc);
230 if (!skb)
231 return NULL;
232
233 len = qdisc_pkt_len(skb);
234
235 /* As sendslope is a negative number, this will decrease the
236 * amount of q->credits.
237 */
238 credits = credits_from_len(len, q->sendslope,
239 atomic64_read(&q->port_rate));
240 credits += q->credits;
241
242 q->credits = max_t(s64, credits, q->locredit);
243 /* Estimate of the transmission of the last byte of the packet in ns */
244 if (unlikely(atomic64_read(&q->port_rate) == 0))
245 q->last = now;
246 else
247 q->last = now + div64_s64(len * NSEC_PER_SEC,
248 atomic64_read(&q->port_rate));
249
250 return skb;
251 }
252
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
diff --git a/net/sched/sch_cbs.c b/net/sched/sch_cbs.c index 2eaac2ff380f..b870576839d1 100644 --- a/net/sched/sch_cbs.c +++ b/net/sched/sch_cbs.c @@ -76,7 +76,9 @@ struct cbs_sched_data { s32 hicredit; /* in bytes */ s64 sendslope; /* in bytes/s */ s64 idleslope; /* in bytes/s */ - struct qdisc_watchdog watchdog; + struct hrtimer timer; + struct Qdisc *sch; + u64 last_expires; int (*enqueue)(struct sk_buff *skb, struct Qdisc *sch, struct sk_buff **to_free); struct sk_buff *(*dequeue)(struct Qdisc *sch); @@ -84,6 +86,41 @@ struct cbs_sched_data { struct list_head cbs_list; }; +/* timediff is in ns, slope is in bytes/s */ +static s64 timediff_to_credits(s64 timediff, s64 slope) +{ + return div64_s64(timediff * slope, NSEC_PER_SEC); +} + +static void cbs_timer_schedule(struct cbs_sched_data *q, u64 expires) +{ + if (test_bit(__QDISC_STATE_DEACTIVATED, + &qdisc_root_sleeping(q->sch)->state)) + return; + if (q->last_expires == expires) + return; + q->last_expires = expires; + hrtimer_start(&q->timer, + ns_to_ktime(expires), + HRTIMER_MODE_ABS_PINNED); + +} +static enum hrtimer_restart cbs_timer(struct hrtimer *timer) +{ + struct cbs_sched_data *q = container_of(timer, struct cbs_sched_data, timer); + s64 now = ktime_get_ns(); + s64 credits; + + credits = timediff_to_credits(now- q->last, q->idleslope); + credits = q->credits+ credits; + q->credits = clamp_t(s64, credits, q->locredit, q->hicredit); + q->last = now; + rcu_read_lock(); + __netif_schedule(qdisc_root(q->sch)); + rcu_read_unlock(); + + return HRTIMER_NORESTART; +} static int cbs_child_enqueue(struct sk_buff *skb, struct Qdisc *sch, struct Qdisc *child, struct sk_buff **to_free) @@ -135,12 +172,6 @@ static int cbs_enqueue(struct sk_buff *skb, struct Qdisc *sch, return q->enqueue(skb, sch, to_free); } -/* timediff is in ns, slope is in bytes/s */ -static s64 timediff_to_credits(s64 timediff, s64 slope) -{ - return div64_s64(timediff * slope, NSEC_PER_SEC); -} - static s64 delay_from_credits(s64 credits, s64 slope) { if (unlikely(slope == 0)) @@ -183,25 +214,17 @@ static struct sk_buff *cbs_dequeue_soft(struct Qdisc *sch) /* The previous packet is still being sent */ if (now < q->last) { - qdisc_watchdog_schedule_ns(&q->watchdog, q->last); + cbs_timer_schedule(q, q->last); return NULL; } if (q->credits < 0) { - credits = timediff_to_credits(now - q->last, q->idleslope); - - credits = q->credits + credits; - q->credits = min_t(s64, credits, q->hicredit); - - if (q->credits < 0) { - s64 delay; - - delay = delay_from_credits(q->credits, q->idleslope); - qdisc_watchdog_schedule_ns(&q->watchdog, now + delay); + s64 delay; - q->last = now; + delay = delay_from_credits(q->credits, q->idleslope); + cbs_timer_schedule(q, now+ delay); + q->last = now; - return NULL; - } + return NULL; } skb = cbs_child_dequeue(sch, qdisc); if (!skb) @@ -424,7 +447,9 @@ static int cbs_init(struct Qdisc *sch, struct nlattr *opt, q->enqueue = cbs_enqueue_soft; q->dequeue = cbs_dequeue_soft; - qdisc_watchdog_init(&q->watchdog, sch); + hrtimer_init(&q->timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_PINNED); + q->timer.function = cbs_timer; + q->sch = sch; return cbs_change(sch, opt, extack); } @@ -438,7 +463,7 @@ static void cbs_destroy(struct Qdisc *sch) if (!q->qdisc) return; - qdisc_watchdog_cancel(&q->watchdog); + hrtimer_cancel(&q->timer); cbs_disable_offload(dev, q); spin_lock(&cbs_list_lock);
in the function cbs_dequeue_soft, when q->credits< 0, (now- q->last) should be accounted for sendslope, not idleslope. so the solution is as follows: when q->credits is less than 0, directly calculate delay time, activate hrtimer and when hrtimer fires, calculate idleslope credits and update it to q->credits. Signed-off-by: Xiaoyong Yan <yanxiaoyong5@gmail.com> --- net/sched/sch_cbs.c | 71 ++++++++++++++++++++++++++++++--------------- 1 file changed, 48 insertions(+), 23 deletions(-)