diff mbox series

[v2,net-next] net_sched: sch_fq: add three drop_reason

Message ID 20241204171950.89829-1-edumazet@google.com (mailing list archive)
State Accepted
Delegated to: Netdev Maintainers
Headers show
Series [v2,net-next] net_sched: sch_fq: add three drop_reason | expand

Checks

Context Check Description
netdev/series_format success Single patches do not need cover letters
netdev/tree_selection success Clearly marked for net-next
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 43 this patch: 43
netdev/build_tools success Errors and warnings before: 0 (+23) this patch: 0 (+23)
netdev/cc_maintainers warning 1 maintainers not CCed: horms@kernel.org
netdev/build_clang success Errors and warnings before: 80 this patch: 80
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 5304 this patch: 5304
netdev/checkpatch warning CHECK: Please don't use multiple blank lines CHECK: Please use a blank line after function/struct/union/enum declarations
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
netdev/contest success net-next-2024-12-05--06-00 (tests: 760)

Commit Message

Eric Dumazet Dec. 4, 2024, 5:19 p.m. UTC 
Add three new drop_reason, more precise than generic QDISC_DROP:

"tc -s qd" show aggregate counters, it might be more useful
to use drop_reason infrastructure for bug hunting.

1) SKB_DROP_REASON_FQ_BAND_LIMIT
   Whenever a packet is added while its band limit is hit.
   Corresponding value in "tc -s qd" is bandX_drops XXXX

2) SKB_DROP_REASON_FQ_HORIZON_LIMIT
   Whenever a packet has a timestamp too far in the future.
   Corresponding value in "tc -s qd" is horizon_drops XXXX

3) SKB_DROP_REASON_FQ_FLOW_LIMIT
   Whenever a flow has reached its limit.
   Corresponding value in "tc -s qd" is flows_plimit XXXX

Tested:
tc qd replace dev eth1 root fq flow_limit 10 limit 100000
perf record -a -e skb:kfree_skb sleep 1; perf script

      udp_stream   12329 [004]   216.929492: skb:kfree_skb: skbaddr=0xffff888eabe17e00 rx_sk=(nil) protocol=34525 location=__dev_queue_xmit+0x9d9 reason: FQ_FLOW_LIMIT
      udp_stream   12385 [006]   216.929593: skb:kfree_skb: skbaddr=0xffff888ef8827f00 rx_sk=(nil) protocol=34525 location=__dev_queue_xmit+0x9d9 reason: FQ_FLOW_LIMIT
      udp_stream   12389 [005]   216.929871: skb:kfree_skb: skbaddr=0xffff888ecb9ba500 rx_sk=(nil) protocol=34525 location=__dev_queue_xmit+0x9d9 reason: FQ_FLOW_LIMIT
      udp_stream   12316 [009]   216.930398: skb:kfree_skb: skbaddr=0xffff888eca286b00 rx_sk=(nil) protocol=34525 location=__dev_queue_xmit+0x9d9 reason: FQ_FLOW_LIMIT
      udp_stream   12400 [008]   216.930490: skb:kfree_skb: skbaddr=0xffff888eabf93d00 rx_sk=(nil) protocol=34525 location=__dev_queue_xmit+0x9d9 reason: FQ_FLOW_LIMIT

tc qd replace dev eth1 root fq flow_limit 100 limit 10000
perf record -a -e skb:kfree_skb sleep 1; perf script

      udp_stream   18074 [001]  1058.318040: skb:kfree_skb: skbaddr=0xffffa23c881fc000 rx_sk=(nil) protocol=34525 location=__dev_queue_xmit+0x9d9 reason: FQ_BAND_LIMIT
      udp_stream   18126 [005]  1058.320651: skb:kfree_skb: skbaddr=0xffffa23c6aad4000 rx_sk=(nil) protocol=34525 location=__dev_queue_xmit+0x9d9 reason: FQ_BAND_LIMIT
      udp_stream   18118 [006]  1058.321065: skb:kfree_skb: skbaddr=0xffffa23df0d48a00 rx_sk=(nil) protocol=34525 location=__dev_queue_xmit+0x9d9 reason: FQ_BAND_LIMIT
      udp_stream   18074 [001]  1058.321126: skb:kfree_skb: skbaddr=0xffffa23c881ffa00 rx_sk=(nil) protocol=34525 location=__dev_queue_xmit+0x9d9 reason: FQ_BAND_LIMIT
      udp_stream   15815 [003]  1058.321224: skb:kfree_skb: skbaddr=0xffffa23c9835db00 rx_sk=(nil) protocol=34525 location=__dev_queue_xmit+0x9d9 reason: FQ_BAND_LIMIT

tc -s -d qd sh dev eth1
qdisc fq 8023: root refcnt 257 limit 10000p flow_limit 100p buckets 1024 orphan_mask 1023
 bands 3 priomap 1 2 2 2 1 2 0 0 1 1 1 1 1 1 1 1 weights 589824 196608 65536 quantum 18Kb
 initial_quantum 92120b low_rate_threshold 550Kbit refill_delay 40ms
 timer_slack 10us horizon 10s horizon_drop
 Sent 492439603330 bytes 336953991 pkt (dropped 61724094, overlimits 0 requeues 4463)
 backlog 14611228b 9995p requeues 4463
  flows 2965 (inactive 1151 throttled 0) band0_pkts 0 band1_pkts 9993 band2_pkts 0
  gc 6347 highprio 0 fastpath 30 throttled 5 latency 2.32us flows_plimit 7403693
 band1_drops 54320401

Signed-off-by: Eric Dumazet <edumazet@google.com>
---
v2: Addressed Cong feedback from v1
    v1: https://lore.kernel.org/netdev/CANn89iLofU1dnwAf-4ezn08h=o82ZPCHc3QJSMUdC+5aUhRsgA@mail.gmail.com/T/#t
---
 include/net/dropreason-core.h | 18 ++++++++++++++++++
 include/net/sch_generic.h     |  9 +++++++++
 net/sched/sch_fq.c            | 14 ++++++++++----
 3 files changed, 37 insertions(+), 4 deletions(-)

Comments

Victor Nogueira Dec. 5, 2024, 1:07 a.m. UTC | #1 
On 04/12/2024 14:19, Eric Dumazet wrote:
> Add three new drop_reason, more precise than generic QDISC_DROP:
> 
> "tc -s qd" show aggregate counters, it might be more useful
> to use drop_reason infrastructure for bug hunting.
> 
> 1) SKB_DROP_REASON_FQ_BAND_LIMIT
>     Whenever a packet is added while its band limit is hit.
>     Corresponding value in "tc -s qd" is bandX_drops XXXX
> 
> 2) SKB_DROP_REASON_FQ_HORIZON_LIMIT
>     Whenever a packet has a timestamp too far in the future.
>     Corresponding value in "tc -s qd" is horizon_drops XXXX
> 
> 3) SKB_DROP_REASON_FQ_FLOW_LIMIT
>     Whenever a flow has reached its limit.
>     Corresponding value in "tc -s qd" is flows_plimit XXXX
> 
> Tested:
> tc qd replace dev eth1 root fq flow_limit 10 limit 100000
> perf record -a -e skb:kfree_skb sleep 1; perf script
> 
>        udp_stream   12329 [004]   216.929492: skb:kfree_skb: skbaddr=0xffff888eabe17e00 rx_sk=(nil) protocol=34525 location=__dev_queue_xmit+0x9d9 reason: FQ_FLOW_LIMIT
>        udp_stream   12385 [006]   216.929593: skb:kfree_skb: skbaddr=0xffff888ef8827f00 rx_sk=(nil) protocol=34525 location=__dev_queue_xmit+0x9d9 reason: FQ_FLOW_LIMIT
>        udp_stream   12389 [005]   216.929871: skb:kfree_skb: skbaddr=0xffff888ecb9ba500 rx_sk=(nil) protocol=34525 location=__dev_queue_xmit+0x9d9 reason: FQ_FLOW_LIMIT
>        udp_stream   12316 [009]   216.930398: skb:kfree_skb: skbaddr=0xffff888eca286b00 rx_sk=(nil) protocol=34525 location=__dev_queue_xmit+0x9d9 reason: FQ_FLOW_LIMIT
>        udp_stream   12400 [008]   216.930490: skb:kfree_skb: skbaddr=0xffff888eabf93d00 rx_sk=(nil) protocol=34525 location=__dev_queue_xmit+0x9d9 reason: FQ_FLOW_LIMIT
> 
> tc qd replace dev eth1 root fq flow_limit 100 limit 10000
> perf record -a -e skb:kfree_skb sleep 1; perf script
> 
>        udp_stream   18074 [001]  1058.318040: skb:kfree_skb: skbaddr=0xffffa23c881fc000 rx_sk=(nil) protocol=34525 location=__dev_queue_xmit+0x9d9 reason: FQ_BAND_LIMIT
>        udp_stream   18126 [005]  1058.320651: skb:kfree_skb: skbaddr=0xffffa23c6aad4000 rx_sk=(nil) protocol=34525 location=__dev_queue_xmit+0x9d9 reason: FQ_BAND_LIMIT
>        udp_stream   18118 [006]  1058.321065: skb:kfree_skb: skbaddr=0xffffa23df0d48a00 rx_sk=(nil) protocol=34525 location=__dev_queue_xmit+0x9d9 reason: FQ_BAND_LIMIT
>        udp_stream   18074 [001]  1058.321126: skb:kfree_skb: skbaddr=0xffffa23c881ffa00 rx_sk=(nil) protocol=34525 location=__dev_queue_xmit+0x9d9 reason: FQ_BAND_LIMIT
>        udp_stream   15815 [003]  1058.321224: skb:kfree_skb: skbaddr=0xffffa23c9835db00 rx_sk=(nil) protocol=34525 location=__dev_queue_xmit+0x9d9 reason: FQ_BAND_LIMIT
> 
> tc -s -d qd sh dev eth1
> qdisc fq 8023: root refcnt 257 limit 10000p flow_limit 100p buckets 1024 orphan_mask 1023
>   bands 3 priomap 1 2 2 2 1 2 0 0 1 1 1 1 1 1 1 1 weights 589824 196608 65536 quantum 18Kb
>   initial_quantum 92120b low_rate_threshold 550Kbit refill_delay 40ms
>   timer_slack 10us horizon 10s horizon_drop
>   Sent 492439603330 bytes 336953991 pkt (dropped 61724094, overlimits 0 requeues 4463)
>   backlog 14611228b 9995p requeues 4463
>    flows 2965 (inactive 1151 throttled 0) band0_pkts 0 band1_pkts 9993 band2_pkts 0
>    gc 6347 highprio 0 fastpath 30 throttled 5 latency 2.32us flows_plimit 7403693
>   band1_drops 54320401
> 
> Signed-off-by: Eric Dumazet <edumazet@google.com>

Reviewed-by: Victor Nogueira <victor@mojatatu.com>
Toke Høiland-Jørgensen Dec. 5, 2024, 11:57 a.m. UTC | #2 
Eric Dumazet <edumazet@google.com> writes:

> Add three new drop_reason, more precise than generic QDISC_DROP:
>
> "tc -s qd" show aggregate counters, it might be more useful
> to use drop_reason infrastructure for bug hunting.
>
> 1) SKB_DROP_REASON_FQ_BAND_LIMIT
>    Whenever a packet is added while its band limit is hit.
>    Corresponding value in "tc -s qd" is bandX_drops XXXX
>
> 2) SKB_DROP_REASON_FQ_HORIZON_LIMIT
>    Whenever a packet has a timestamp too far in the future.
>    Corresponding value in "tc -s qd" is horizon_drops XXXX
>
> 3) SKB_DROP_REASON_FQ_FLOW_LIMIT
>    Whenever a flow has reached its limit.
>    Corresponding value in "tc -s qd" is flows_plimit XXXX
>
> Tested:
> tc qd replace dev eth1 root fq flow_limit 10 limit 100000
> perf record -a -e skb:kfree_skb sleep 1; perf script
>
>       udp_stream   12329 [004]   216.929492: skb:kfree_skb: skbaddr=0xffff888eabe17e00 rx_sk=(nil) protocol=34525 location=__dev_queue_xmit+0x9d9 reason: FQ_FLOW_LIMIT
>       udp_stream   12385 [006]   216.929593: skb:kfree_skb: skbaddr=0xffff888ef8827f00 rx_sk=(nil) protocol=34525 location=__dev_queue_xmit+0x9d9 reason: FQ_FLOW_LIMIT
>       udp_stream   12389 [005]   216.929871: skb:kfree_skb: skbaddr=0xffff888ecb9ba500 rx_sk=(nil) protocol=34525 location=__dev_queue_xmit+0x9d9 reason: FQ_FLOW_LIMIT
>       udp_stream   12316 [009]   216.930398: skb:kfree_skb: skbaddr=0xffff888eca286b00 rx_sk=(nil) protocol=34525 location=__dev_queue_xmit+0x9d9 reason: FQ_FLOW_LIMIT
>       udp_stream   12400 [008]   216.930490: skb:kfree_skb: skbaddr=0xffff888eabf93d00 rx_sk=(nil) protocol=34525 location=__dev_queue_xmit+0x9d9 reason: FQ_FLOW_LIMIT
>
> tc qd replace dev eth1 root fq flow_limit 100 limit 10000
> perf record -a -e skb:kfree_skb sleep 1; perf script
>
>       udp_stream   18074 [001]  1058.318040: skb:kfree_skb: skbaddr=0xffffa23c881fc000 rx_sk=(nil) protocol=34525 location=__dev_queue_xmit+0x9d9 reason: FQ_BAND_LIMIT
>       udp_stream   18126 [005]  1058.320651: skb:kfree_skb: skbaddr=0xffffa23c6aad4000 rx_sk=(nil) protocol=34525 location=__dev_queue_xmit+0x9d9 reason: FQ_BAND_LIMIT
>       udp_stream   18118 [006]  1058.321065: skb:kfree_skb: skbaddr=0xffffa23df0d48a00 rx_sk=(nil) protocol=34525 location=__dev_queue_xmit+0x9d9 reason: FQ_BAND_LIMIT
>       udp_stream   18074 [001]  1058.321126: skb:kfree_skb: skbaddr=0xffffa23c881ffa00 rx_sk=(nil) protocol=34525 location=__dev_queue_xmit+0x9d9 reason: FQ_BAND_LIMIT
>       udp_stream   15815 [003]  1058.321224: skb:kfree_skb: skbaddr=0xffffa23c9835db00 rx_sk=(nil) protocol=34525 location=__dev_queue_xmit+0x9d9 reason: FQ_BAND_LIMIT
>
> tc -s -d qd sh dev eth1
> qdisc fq 8023: root refcnt 257 limit 10000p flow_limit 100p buckets 1024 orphan_mask 1023
>  bands 3 priomap 1 2 2 2 1 2 0 0 1 1 1 1 1 1 1 1 weights 589824 196608 65536 quantum 18Kb
>  initial_quantum 92120b low_rate_threshold 550Kbit refill_delay 40ms
>  timer_slack 10us horizon 10s horizon_drop
>  Sent 492439603330 bytes 336953991 pkt (dropped 61724094, overlimits 0 requeues 4463)
>  backlog 14611228b 9995p requeues 4463
>   flows 2965 (inactive 1151 throttled 0) band0_pkts 0 band1_pkts 9993 band2_pkts 0
>   gc 6347 highprio 0 fastpath 30 throttled 5 latency 2.32us flows_plimit 7403693
>  band1_drops 54320401
>
> Signed-off-by: Eric Dumazet <edumazet@google.com>

Nice to see qdisc-specific drop reasons - guess I should look at this
for sch_cake as well!

Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com>
Jamal Hadi Salim Dec. 5, 2024, 12:41 p.m. UTC | #3 
On Thu, Dec 5, 2024 at 6:57 AM Toke Høiland-Jørgensen <toke@redhat.com> wrote:
>
> Eric Dumazet <edumazet@google.com> writes:
>
> > Add three new drop_reason, more precise than generic QDISC_DROP:
> >
> > "tc -s qd" show aggregate counters, it might be more useful
> > to use drop_reason infrastructure for bug hunting.
> >
> > 1) SKB_DROP_REASON_FQ_BAND_LIMIT
> >    Whenever a packet is added while its band limit is hit.
> >    Corresponding value in "tc -s qd" is bandX_drops XXXX
> >
> > 2) SKB_DROP_REASON_FQ_HORIZON_LIMIT
> >    Whenever a packet has a timestamp too far in the future.
> >    Corresponding value in "tc -s qd" is horizon_drops XXXX
> >
> > 3) SKB_DROP_REASON_FQ_FLOW_LIMIT
> >    Whenever a flow has reached its limit.
> >    Corresponding value in "tc -s qd" is flows_plimit XXXX
> >
> > Tested:
> > tc qd replace dev eth1 root fq flow_limit 10 limit 100000
> > perf record -a -e skb:kfree_skb sleep 1; perf script
> >
> >       udp_stream   12329 [004]   216.929492: skb:kfree_skb: skbaddr=0xffff888eabe17e00 rx_sk=(nil) protocol=34525 location=__dev_queue_xmit+0x9d9 reason: FQ_FLOW_LIMIT
> >       udp_stream   12385 [006]   216.929593: skb:kfree_skb: skbaddr=0xffff888ef8827f00 rx_sk=(nil) protocol=34525 location=__dev_queue_xmit+0x9d9 reason: FQ_FLOW_LIMIT
> >       udp_stream   12389 [005]   216.929871: skb:kfree_skb: skbaddr=0xffff888ecb9ba500 rx_sk=(nil) protocol=34525 location=__dev_queue_xmit+0x9d9 reason: FQ_FLOW_LIMIT
> >       udp_stream   12316 [009]   216.930398: skb:kfree_skb: skbaddr=0xffff888eca286b00 rx_sk=(nil) protocol=34525 location=__dev_queue_xmit+0x9d9 reason: FQ_FLOW_LIMIT
> >       udp_stream   12400 [008]   216.930490: skb:kfree_skb: skbaddr=0xffff888eabf93d00 rx_sk=(nil) protocol=34525 location=__dev_queue_xmit+0x9d9 reason: FQ_FLOW_LIMIT
> >
> > tc qd replace dev eth1 root fq flow_limit 100 limit 10000
> > perf record -a -e skb:kfree_skb sleep 1; perf script
> >
> >       udp_stream   18074 [001]  1058.318040: skb:kfree_skb: skbaddr=0xffffa23c881fc000 rx_sk=(nil) protocol=34525 location=__dev_queue_xmit+0x9d9 reason: FQ_BAND_LIMIT
> >       udp_stream   18126 [005]  1058.320651: skb:kfree_skb: skbaddr=0xffffa23c6aad4000 rx_sk=(nil) protocol=34525 location=__dev_queue_xmit+0x9d9 reason: FQ_BAND_LIMIT
> >       udp_stream   18118 [006]  1058.321065: skb:kfree_skb: skbaddr=0xffffa23df0d48a00 rx_sk=(nil) protocol=34525 location=__dev_queue_xmit+0x9d9 reason: FQ_BAND_LIMIT
> >       udp_stream   18074 [001]  1058.321126: skb:kfree_skb: skbaddr=0xffffa23c881ffa00 rx_sk=(nil) protocol=34525 location=__dev_queue_xmit+0x9d9 reason: FQ_BAND_LIMIT
> >       udp_stream   15815 [003]  1058.321224: skb:kfree_skb: skbaddr=0xffffa23c9835db00 rx_sk=(nil) protocol=34525 location=__dev_queue_xmit+0x9d9 reason: FQ_BAND_LIMIT
> >
> > tc -s -d qd sh dev eth1
> > qdisc fq 8023: root refcnt 257 limit 10000p flow_limit 100p buckets 1024 orphan_mask 1023
> >  bands 3 priomap 1 2 2 2 1 2 0 0 1 1 1 1 1 1 1 1 weights 589824 196608 65536 quantum 18Kb
> >  initial_quantum 92120b low_rate_threshold 550Kbit refill_delay 40ms
> >  timer_slack 10us horizon 10s horizon_drop
> >  Sent 492439603330 bytes 336953991 pkt (dropped 61724094, overlimits 0 requeues 4463)
> >  backlog 14611228b 9995p requeues 4463
> >   flows 2965 (inactive 1151 throttled 0) band0_pkts 0 band1_pkts 9993 band2_pkts 0
> >   gc 6347 highprio 0 fastpath 30 throttled 5 latency 2.32us flows_plimit 7403693
> >  band1_drops 54320401
> >
> > Signed-off-by: Eric Dumazet <edumazet@google.com>
>
> Nice to see qdisc-specific drop reasons - guess I should look at this
> for sch_cake as well!
>
> Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com>

Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>

cheers,
jamal
Jakub Kicinski Dec. 8, 2024, 2:43 a.m. UTC | #4 
On Wed,  4 Dec 2024 17:19:50 +0000 Eric Dumazet wrote:
> Add three new drop_reason, more precise than generic QDISC_DROP:

FTR I applied this a while back, thanks!
diff mbox series

Patch

diff --git a/include/net/dropreason-core.h b/include/net/dropreason-core.h
index 6c5a1ea209a22d8702f8c982762ca5f69791b8eb..c29282fabae6cdf9dd79f698b92b4b8f57156b1e 100644
--- a/include/net/dropreason-core.h
+++ b/include/net/dropreason-core.h
@@ -58,6 +58,9 @@ 
 	FN(TC_EGRESS)			\
 	FN(SECURITY_HOOK)		\
 	FN(QDISC_DROP)			\
+	FN(FQ_BAND_LIMIT)		\
+	FN(FQ_HORIZON_LIMIT)		\
+	FN(FQ_FLOW_LIMIT)		\
 	FN(CPU_BACKLOG)			\
 	FN(XDP)				\
 	FN(TC_INGRESS)			\
@@ -311,6 +314,21 @@  enum skb_drop_reason {
 	 * failed to enqueue to current qdisc)
 	 */
 	SKB_DROP_REASON_QDISC_DROP,
+	/**
+	 * @SKB_DROP_REASON_FQ_BAND_LIMIT: dropped by fq qdisc when per band
+	 * limit is reached.
+	 */
+	SKB_DROP_REASON_FQ_BAND_LIMIT,
+	/**
+	 * @SKB_DROP_REASON_FQ_HORIZON_LIMIT: dropped by fq qdisc when packet
+	 * timestamp is too far in the future.
+	 */
+	SKB_DROP_REASON_FQ_HORIZON_LIMIT,
+	/**
+	 * @SKB_DROP_REASON_FQ_FLOW_LIMIT: dropped by fq qdisc when a flow
+	 * exceeds its limits.
+	 */
+	SKB_DROP_REASON_FQ_FLOW_LIMIT,
 	/**
 	 * @SKB_DROP_REASON_CPU_BACKLOG: failed to enqueue the skb to the per CPU
 	 * backlog queue. This can be caused by backlog queue full (see
diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h
index 5d74fa7e694cc85be91dbf01f0876b9feaa29115..c7a33c2c69830a6cbff8f6359de7cc468c2e845e 100644
--- a/include/net/sch_generic.h
+++ b/include/net/sch_generic.h
@@ -1245,6 +1245,15 @@  static inline int qdisc_drop(struct sk_buff *skb, struct Qdisc *sch,
 	return NET_XMIT_DROP;
 }
 
+static inline int qdisc_drop_reason(struct sk_buff *skb, struct Qdisc *sch,
+				    struct sk_buff **to_free,
+				    enum skb_drop_reason reason)
+{
+	tcf_set_drop_reason(skb, reason);
+	return qdisc_drop(skb, sch, to_free);
+}
+
+
 static inline int qdisc_drop_all(struct sk_buff *skb, struct Qdisc *sch,
 				 struct sk_buff **to_free)
 {
diff --git a/net/sched/sch_fq.c b/net/sched/sch_fq.c
index a5e87f9ea9861cbedb7ce858fbbcabb5d67cf821..2ca5332cfcc5c52bf30e6f8337814a656b919b17 100644
--- a/net/sched/sch_fq.c
+++ b/net/sched/sch_fq.c
@@ -537,6 +537,8 @@  static bool fq_packet_beyond_horizon(const struct sk_buff *skb,
 	return unlikely((s64)skb->tstamp > (s64)(now + q->horizon));
 }
 
+#define FQDR(reason) SKB_DROP_REASON_FQ_##reason
+
 static int fq_enqueue(struct sk_buff *skb, struct Qdisc *sch,
 		      struct sk_buff **to_free)
 {
@@ -548,7 +550,8 @@  static int fq_enqueue(struct sk_buff *skb, struct Qdisc *sch,
 	band = fq_prio2band(q->prio2band, skb->priority & TC_PRIO_MAX);
 	if (unlikely(q->band_pkt_count[band] >= sch->limit)) {
 		q->stat_band_drops[band]++;
-		return qdisc_drop(skb, sch, to_free);
+		return qdisc_drop_reason(skb, sch, to_free,
+					 FQDR(BAND_LIMIT));
 	}
 
 	now = ktime_get_ns();
@@ -558,8 +561,9 @@  static int fq_enqueue(struct sk_buff *skb, struct Qdisc *sch,
 		/* Check if packet timestamp is too far in the future. */
 		if (fq_packet_beyond_horizon(skb, q, now)) {
 			if (q->horizon_drop) {
-					q->stat_horizon_drops++;
-					return qdisc_drop(skb, sch, to_free);
+				q->stat_horizon_drops++;
+				return qdisc_drop_reason(skb, sch, to_free,
+							 FQDR(HORIZON_LIMIT));
 			}
 			q->stat_horizon_caps++;
 			skb->tstamp = now + q->horizon;
@@ -572,7 +576,8 @@  static int fq_enqueue(struct sk_buff *skb, struct Qdisc *sch,
 	if (f != &q->internal) {
 		if (unlikely(f->qlen >= q->flow_plimit)) {
 			q->stat_flows_plimit++;
-			return qdisc_drop(skb, sch, to_free);
+			return qdisc_drop_reason(skb, sch, to_free,
+						 FQDR(FLOW_LIMIT));
 		}
 
 		if (fq_flow_is_detached(f)) {
@@ -597,6 +602,7 @@  static int fq_enqueue(struct sk_buff *skb, struct Qdisc *sch,
 
 	return NET_XMIT_SUCCESS;
 }
+#undef FQDR
 
 static void fq_check_throttled(struct fq_sched_data *q, u64 now)
 {