|
|
@@ -1,217 +0,0 @@
|
|
|
-From 712639929912c5eefb09facccb48d55b3f72c9f8 Mon Sep 17 00:00:00 2001
|
|
|
-From: George Amanakis <[email protected]>
|
|
|
-Date: Fri, 1 Mar 2019 16:04:05 +0100
|
|
|
-Subject: [PATCH] sch_cake: Make the dual modes fairer
|
|
|
-MIME-Version: 1.0
|
|
|
-Content-Type: text/plain; charset=UTF-8
|
|
|
-Content-Transfer-Encoding: 8bit
|
|
|
-
|
|
|
-CAKE host fairness does not work well with TCP flows in dual-srchost and
|
|
|
-dual-dsthost setup. The reason is that ACKs generated by TCP flows are
|
|
|
-classified as sparse flows, and affect flow isolation from other hosts. Fix
|
|
|
-this by calculating host_load based only on the bulk flows a host
|
|
|
-generates. In a hash collision the host_bulk_flow_count values must be
|
|
|
-decremented on the old hosts and incremented on the new ones *if* the queue
|
|
|
-is in the bulk set.
|
|
|
-
|
|
|
-Reported-by: Pete Heist <[email protected]>
|
|
|
-Signed-off-by: George Amanakis <[email protected]>
|
|
|
-Signed-off-by: Toke Høiland-Jørgensen <[email protected]>
|
|
|
-Signed-off-by: David S. Miller <[email protected]>
|
|
|
-Signed-off-by: Kevin Darbyshire-Bryant <[email protected]>
|
|
|
----
|
|
|
- net/sched/sch_cake.c | 92 ++++++++++++++++++++++++++++++--------------
|
|
|
- 1 file changed, 63 insertions(+), 29 deletions(-)
|
|
|
-
|
|
|
---- a/net/sched/sch_cake.c
|
|
|
-+++ b/net/sched/sch_cake.c
|
|
|
-@@ -138,8 +138,8 @@ struct cake_flow {
|
|
|
- struct cake_host {
|
|
|
- u32 srchost_tag;
|
|
|
- u32 dsthost_tag;
|
|
|
-- u16 srchost_refcnt;
|
|
|
-- u16 dsthost_refcnt;
|
|
|
-+ u16 srchost_bulk_flow_count;
|
|
|
-+ u16 dsthost_bulk_flow_count;
|
|
|
- };
|
|
|
-
|
|
|
- struct cake_heap_entry {
|
|
|
-@@ -746,8 +746,10 @@ skip_hash:
|
|
|
- * queue, accept the collision, update the host tags.
|
|
|
- */
|
|
|
- q->way_collisions++;
|
|
|
-- q->hosts[q->flows[reduced_hash].srchost].srchost_refcnt--;
|
|
|
-- q->hosts[q->flows[reduced_hash].dsthost].dsthost_refcnt--;
|
|
|
-+ if (q->flows[outer_hash + k].set == CAKE_SET_BULK) {
|
|
|
-+ q->hosts[q->flows[reduced_hash].srchost].srchost_bulk_flow_count--;
|
|
|
-+ q->hosts[q->flows[reduced_hash].dsthost].dsthost_bulk_flow_count--;
|
|
|
-+ }
|
|
|
- allocate_src = cake_dsrc(flow_mode);
|
|
|
- allocate_dst = cake_ddst(flow_mode);
|
|
|
- found:
|
|
|
-@@ -767,13 +769,14 @@ found:
|
|
|
- }
|
|
|
- for (i = 0; i < CAKE_SET_WAYS;
|
|
|
- i++, k = (k + 1) % CAKE_SET_WAYS) {
|
|
|
-- if (!q->hosts[outer_hash + k].srchost_refcnt)
|
|
|
-+ if (!q->hosts[outer_hash + k].srchost_bulk_flow_count)
|
|
|
- break;
|
|
|
- }
|
|
|
- q->hosts[outer_hash + k].srchost_tag = srchost_hash;
|
|
|
- found_src:
|
|
|
- srchost_idx = outer_hash + k;
|
|
|
-- q->hosts[srchost_idx].srchost_refcnt++;
|
|
|
-+ if (q->flows[reduced_hash].set == CAKE_SET_BULK)
|
|
|
-+ q->hosts[srchost_idx].srchost_bulk_flow_count++;
|
|
|
- q->flows[reduced_hash].srchost = srchost_idx;
|
|
|
- }
|
|
|
-
|
|
|
-@@ -789,13 +792,14 @@ found_src:
|
|
|
- }
|
|
|
- for (i = 0; i < CAKE_SET_WAYS;
|
|
|
- i++, k = (k + 1) % CAKE_SET_WAYS) {
|
|
|
-- if (!q->hosts[outer_hash + k].dsthost_refcnt)
|
|
|
-+ if (!q->hosts[outer_hash + k].dsthost_bulk_flow_count)
|
|
|
- break;
|
|
|
- }
|
|
|
- q->hosts[outer_hash + k].dsthost_tag = dsthost_hash;
|
|
|
- found_dst:
|
|
|
- dsthost_idx = outer_hash + k;
|
|
|
-- q->hosts[dsthost_idx].dsthost_refcnt++;
|
|
|
-+ if (q->flows[reduced_hash].set == CAKE_SET_BULK)
|
|
|
-+ q->hosts[dsthost_idx].dsthost_bulk_flow_count++;
|
|
|
- q->flows[reduced_hash].dsthost = dsthost_idx;
|
|
|
- }
|
|
|
- }
|
|
|
-@@ -1793,20 +1797,30 @@ static s32 cake_enqueue(struct sk_buff *
|
|
|
- b->sparse_flow_count++;
|
|
|
-
|
|
|
- if (cake_dsrc(q->flow_mode))
|
|
|
-- host_load = max(host_load, srchost->srchost_refcnt);
|
|
|
-+ host_load = max(host_load, srchost->srchost_bulk_flow_count);
|
|
|
-
|
|
|
- if (cake_ddst(q->flow_mode))
|
|
|
-- host_load = max(host_load, dsthost->dsthost_refcnt);
|
|
|
-+ host_load = max(host_load, dsthost->dsthost_bulk_flow_count);
|
|
|
-
|
|
|
- flow->deficit = (b->flow_quantum *
|
|
|
- quantum_div[host_load]) >> 16;
|
|
|
- } else if (flow->set == CAKE_SET_SPARSE_WAIT) {
|
|
|
-+ struct cake_host *srchost = &b->hosts[flow->srchost];
|
|
|
-+ struct cake_host *dsthost = &b->hosts[flow->dsthost];
|
|
|
-+
|
|
|
- /* this flow was empty, accounted as a sparse flow, but actually
|
|
|
- * in the bulk rotation.
|
|
|
- */
|
|
|
- flow->set = CAKE_SET_BULK;
|
|
|
- b->sparse_flow_count--;
|
|
|
- b->bulk_flow_count++;
|
|
|
-+
|
|
|
-+ if (cake_dsrc(q->flow_mode))
|
|
|
-+ srchost->srchost_bulk_flow_count++;
|
|
|
-+
|
|
|
-+ if (cake_ddst(q->flow_mode))
|
|
|
-+ dsthost->dsthost_bulk_flow_count++;
|
|
|
-+
|
|
|
- }
|
|
|
-
|
|
|
- if (q->buffer_used > q->buffer_max_used)
|
|
|
-@@ -1974,23 +1988,8 @@ retry:
|
|
|
- dsthost = &b->hosts[flow->dsthost];
|
|
|
- host_load = 1;
|
|
|
-
|
|
|
-- if (cake_dsrc(q->flow_mode))
|
|
|
-- host_load = max(host_load, srchost->srchost_refcnt);
|
|
|
--
|
|
|
-- if (cake_ddst(q->flow_mode))
|
|
|
-- host_load = max(host_load, dsthost->dsthost_refcnt);
|
|
|
--
|
|
|
-- WARN_ON(host_load > CAKE_QUEUES);
|
|
|
--
|
|
|
- /* flow isolation (DRR++) */
|
|
|
- if (flow->deficit <= 0) {
|
|
|
-- /* The shifted prandom_u32() is a way to apply dithering to
|
|
|
-- * avoid accumulating roundoff errors
|
|
|
-- */
|
|
|
-- flow->deficit += (b->flow_quantum * quantum_div[host_load] +
|
|
|
-- (prandom_u32() >> 16)) >> 16;
|
|
|
-- list_move_tail(&flow->flowchain, &b->old_flows);
|
|
|
--
|
|
|
- /* Keep all flows with deficits out of the sparse and decaying
|
|
|
- * rotations. No non-empty flow can go into the decaying
|
|
|
- * rotation, so they can't get deficits
|
|
|
-@@ -1999,6 +1998,13 @@ retry:
|
|
|
- if (flow->head) {
|
|
|
- b->sparse_flow_count--;
|
|
|
- b->bulk_flow_count++;
|
|
|
-+
|
|
|
-+ if (cake_dsrc(q->flow_mode))
|
|
|
-+ srchost->srchost_bulk_flow_count++;
|
|
|
-+
|
|
|
-+ if (cake_ddst(q->flow_mode))
|
|
|
-+ dsthost->dsthost_bulk_flow_count++;
|
|
|
-+
|
|
|
- flow->set = CAKE_SET_BULK;
|
|
|
- } else {
|
|
|
- /* we've moved it to the bulk rotation for
|
|
|
-@@ -2008,6 +2014,22 @@ retry:
|
|
|
- flow->set = CAKE_SET_SPARSE_WAIT;
|
|
|
- }
|
|
|
- }
|
|
|
-+
|
|
|
-+ if (cake_dsrc(q->flow_mode))
|
|
|
-+ host_load = max(host_load, srchost->srchost_bulk_flow_count);
|
|
|
-+
|
|
|
-+ if (cake_ddst(q->flow_mode))
|
|
|
-+ host_load = max(host_load, dsthost->dsthost_bulk_flow_count);
|
|
|
-+
|
|
|
-+ WARN_ON(host_load > CAKE_QUEUES);
|
|
|
-+
|
|
|
-+ /* The shifted prandom_u32() is a way to apply dithering to
|
|
|
-+ * avoid accumulating roundoff errors
|
|
|
-+ */
|
|
|
-+ flow->deficit += (b->flow_quantum * quantum_div[host_load] +
|
|
|
-+ (prandom_u32() >> 16)) >> 16;
|
|
|
-+ list_move_tail(&flow->flowchain, &b->old_flows);
|
|
|
-+
|
|
|
- goto retry;
|
|
|
- }
|
|
|
-
|
|
|
-@@ -2028,6 +2050,13 @@ retry:
|
|
|
- &b->decaying_flows);
|
|
|
- if (flow->set == CAKE_SET_BULK) {
|
|
|
- b->bulk_flow_count--;
|
|
|
-+
|
|
|
-+ if (cake_dsrc(q->flow_mode))
|
|
|
-+ srchost->srchost_bulk_flow_count--;
|
|
|
-+
|
|
|
-+ if (cake_ddst(q->flow_mode))
|
|
|
-+ dsthost->dsthost_bulk_flow_count--;
|
|
|
-+
|
|
|
- b->decaying_flow_count++;
|
|
|
- } else if (flow->set == CAKE_SET_SPARSE ||
|
|
|
- flow->set == CAKE_SET_SPARSE_WAIT) {
|
|
|
-@@ -2041,14 +2070,19 @@ retry:
|
|
|
- if (flow->set == CAKE_SET_SPARSE ||
|
|
|
- flow->set == CAKE_SET_SPARSE_WAIT)
|
|
|
- b->sparse_flow_count--;
|
|
|
-- else if (flow->set == CAKE_SET_BULK)
|
|
|
-+ else if (flow->set == CAKE_SET_BULK) {
|
|
|
- b->bulk_flow_count--;
|
|
|
-- else
|
|
|
-+
|
|
|
-+ if (cake_dsrc(q->flow_mode))
|
|
|
-+ srchost->srchost_bulk_flow_count--;
|
|
|
-+
|
|
|
-+ if (cake_ddst(q->flow_mode))
|
|
|
-+ dsthost->dsthost_bulk_flow_count--;
|
|
|
-+
|
|
|
-+ } else
|
|
|
- b->decaying_flow_count--;
|
|
|
-
|
|
|
- flow->set = CAKE_SET_NONE;
|
|
|
-- srchost->srchost_refcnt--;
|
|
|
-- dsthost->dsthost_refcnt--;
|
|
|
- }
|
|
|
- goto begin;
|
|
|
- }
|