[PATCH 1/3] fq.h: Port memory limit mechanism from fq_codel
From: Toke Høiland-Jørgensen <hidden>
Date: 2016-09-23 19:59:09
Also in:
linux-wireless
Subsystem:
networking [general], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
The reusable fairness queueing implementation (fq.h) lacks the memory usage limit that the fq_codel qdisc has. This means that small devices (e.g. WiFi routers) can run out of memory when flooded with a large number of packets. This ports the memory limit feature from fq_codel to fq.h. Signed-off-by: Toke Høiland-Jørgensen <redacted> --- include/net/fq.h | 3 +++ include/net/fq_impl.h | 7 ++++++- 2 files changed, 9 insertions(+), 1 deletion(-)
diff --git a/include/net/fq.h b/include/net/fq.h
index 268b490..6d8521a 100644
--- a/include/net/fq.h
+++ b/include/net/fq.h@@ -72,9 +72,12 @@ struct fq { u32 flows_cnt; u32 perturbation; u32 limit; + u32 memory_limit; + u32 memory_usage; u32 quantum; u32 backlog; u32 overlimit; + u32 overmemory; u32 collisions; };
diff --git a/include/net/fq_impl.h b/include/net/fq_impl.h
index 163f3ed..4e6131c 100644
--- a/include/net/fq_impl.h
+++ b/include/net/fq_impl.h@@ -29,6 +29,7 @@ static struct sk_buff *fq_flow_dequeue(struct fq *fq, tin->backlog_packets--; flow->backlog -= skb->len; fq->backlog--; + fq->memory_usage -= skb->truesize; if (flow->backlog == 0) { list_del_init(&flow->backlogchain);
@@ -154,6 +155,7 @@ static void fq_tin_enqueue(struct fq *fq, flow->backlog += skb->len; tin->backlog_bytes += skb->len; tin->backlog_packets++; + fq->memory_usage += skb->truesize; fq->backlog++; fq_recalc_backlog(fq, tin, flow);
@@ -166,7 +168,7 @@ static void fq_tin_enqueue(struct fq *fq, __skb_queue_tail(&flow->queue, skb); - if (fq->backlog > fq->limit) { + if (fq->backlog > fq->limit || fq->memory_usage > fq->memory_limit) { flow = list_first_entry_or_null(&fq->backlogs, struct fq_flow, backlogchain);
@@ -181,6 +183,8 @@ static void fq_tin_enqueue(struct fq *fq, flow->tin->overlimit++; fq->overlimit++; + if (fq->memory_usage > fq->memory_limit) + fq->overmemory++; } }
@@ -251,6 +255,7 @@ static int fq_init(struct fq *fq, int flows_cnt) fq->perturbation = prandom_u32(); fq->quantum = 300; fq->limit = 8192; + fq->memory_limit = 16 << 20; /* 16 MBytes */ fq->flows = kcalloc(fq->flows_cnt, sizeof(fq->flows[0]), GFP_KERNEL); if (!fq->flows)
--
2.9.3