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| author | Jesper Dangaard Brouer <hawk@kernel.org> | 2026-02-26 16:44:19 +0300 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2026-03-01 02:31:34 +0300 |
| commit | 3e28f8ad478f165260deba751858afac46cffd2f (patch) | |
| tree | cecb6e359e9451eb1e7460b3c2dd0f3b725b4b64 /include | |
| parent | ff2998f29f390d963299103f0b247cc79106ced5 (diff) | |
| download | linux-3e28f8ad478f165260deba751858afac46cffd2f.tar.xz | |
net: sched: sfq: convert to qdisc drop reasons
Convert SFQ to use the new qdisc-specific drop reason infrastructure.
This patch demonstrates how to convert a flow-based qdisc to use the
new enum qdisc_drop_reason. As part of this conversion:
- Add QDISC_DROP_MAXFLOWS for flow table exhaustion
- Rename FQ_FLOW_LIMIT to generic FLOW_LIMIT, now shared by FQ and SFQ
- Use QDISC_DROP_OVERLIMIT for sfq_drop() when overall limit exceeded
- Use QDISC_DROP_FLOW_LIMIT for per-flow depth limit exceeded
The FLOW_LIMIT reason is now a common drop reason for per-flow limits,
applicable to both FQ and SFQ qdiscs.
Signed-off-by: Jesper Dangaard Brouer <hawk@kernel.org>
Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://patch.msgid.link/177211345946.3011628.12770616071857185664.stgit@firesoul
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/net/dropreason-qdisc.h | 18 |
1 files changed, 14 insertions, 4 deletions
diff --git a/include/net/dropreason-qdisc.h b/include/net/dropreason-qdisc.h index 80a2d557e5f7..02a9f580411b 100644 --- a/include/net/dropreason-qdisc.h +++ b/include/net/dropreason-qdisc.h @@ -9,10 +9,11 @@ FN(GENERIC) \ FN(OVERLIMIT) \ FN(CONGESTED) \ + FN(MAXFLOWS) \ FN(CAKE_FLOOD) \ FN(FQ_BAND_LIMIT) \ FN(FQ_HORIZON_LIMIT) \ - FN(FQ_FLOW_LIMIT) \ + FN(FLOW_LIMIT) \ FNe(MAX) #undef FN @@ -60,6 +61,13 @@ enum qdisc_drop_reason { */ QDISC_DROP_CONGESTED, /** + * @QDISC_DROP_MAXFLOWS: packet dropped because the qdisc's flow + * tracking table is full and no free slots are available to allocate + * for a new flow. This indicates flow table exhaustion in flow-based + * qdiscs that maintain per-flow state (e.g., SFQ). + */ + QDISC_DROP_MAXFLOWS, + /** * @QDISC_DROP_CAKE_FLOOD: CAKE qdisc dropped packet due to flood * protection mechanism (BLUE algorithm). This indicates potential * DoS/flood attack or unresponsive flow behavior. @@ -77,10 +85,12 @@ enum qdisc_drop_reason { */ QDISC_DROP_FQ_HORIZON_LIMIT, /** - * @QDISC_DROP_FQ_FLOW_LIMIT: FQ dropped packet because an individual - * flow exceeded its per-flow packet limit. + * @QDISC_DROP_FLOW_LIMIT: packet dropped because an individual flow + * exceeded its per-flow packet/depth limit. Used by FQ and SFQ qdiscs + * to enforce per-flow fairness and prevent a single flow from + * monopolizing queue resources. */ - QDISC_DROP_FQ_FLOW_LIMIT, + QDISC_DROP_FLOW_LIMIT, /** * @QDISC_DROP_MAX: the maximum of qdisc drop reasons, which * shouldn't be used as a real 'reason' - only for tracing code gen |