fq.h: Port memory limit mechanism from fq_codel
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 <toke@toke.dk>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
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 @@
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 @@
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 @@
__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 @@
flow->tin->overlimit++;
fq->overlimit++;
+ if (fq->memory_usage > fq->memory_limit)
+ fq->overmemory++;
}
}
@@ -251,6 +255,7 @@
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)