kernel: don't scrimp on memory on big iron

x86_64 platforms typically don't lack memory, so don't needlessly
economize memory if fq_codel on capable platforms.

Signed-off-by: Philip Prindeville <philipp@redfish-solutions.com>
[Add a comment to the patch]
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>

target/linux/generic/hack-4.9/660-fq_codel_defaults.patch

@@ -3,6 +3,9 @@ From: Felix Fietkau <nbd@nbd.name>
 Date: Fri, 7 Jul 2017 17:21:53 +0200
 Subject:  hack: net: fq_codel: tune defaults for small devices
 
+Assume that x86_64 devices always have a big memory and do not need this 
+optimization compared to devices with only 32 MB or 64 MB RAM.
+
 Signed-off-by: Felix Fietkau <nbd@nbd.name>
 ---
  net/sched/sch_fq_codel.c | 2 +-
@@ -10,12 +13,15 @@ Signed-off-by: Felix Fietkau <nbd@nbd.name>
 
 --- a/net/sched/sch_fq_codel.c
 +++ b/net/sched/sch_fq_codel.c
-@@ -479,7 +479,7 @@ static int fq_codel_init(struct Qdisc *s
+@@ -479,7 +479,11 @@ static int fq_codel_init(struct Qdisc *s
  
  	sch->limit = 10*1024;
  	q->flows_cnt = 1024;
--	q->memory_limit = 32 << 20; /* 32 MBytes */
++#ifdef CONFIG_X86_64
+ 	q->memory_limit = 32 << 20; /* 32 MBytes */
++#else
 +	q->memory_limit = 4 << 20; /* 4 MBytes */
++#endif
  	q->drop_batch_size = 64;
  	q->quantum = psched_mtu(qdisc_dev(sch));
  	q->perturbation = prandom_u32();

target/linux/generic/hack-4.9/661-use_fq_codel_by_default.patch

@@ -55,7 +55,7 @@ Signed-off-by: Felix Fietkau <nbd@nbd.name>
  	register_qdisc(&pfifo_head_drop_qdisc_ops);
 --- a/net/sched/sch_fq_codel.c
 +++ b/net/sched/sch_fq_codel.c
-@@ -705,7 +705,7 @@ static const struct Qdisc_class_ops fq_c
+@@ -709,7 +709,7 @@ static const struct Qdisc_class_ops fq_c
  	.walk		=	fq_codel_walk,
  };
  
@@ -64,7 +64,7 @@ Signed-off-by: Felix Fietkau <nbd@nbd.name>
  	.cl_ops		=	&fq_codel_class_ops,
  	.id		=	"fq_codel",
  	.priv_size	=	sizeof(struct fq_codel_sched_data),
-@@ -720,6 +720,7 @@ static struct Qdisc_ops fq_codel_qdisc_o
+@@ -724,6 +724,7 @@ static struct Qdisc_ops fq_codel_qdisc_o
  	.dump_stats =	fq_codel_dump_stats,
  	.owner		=	THIS_MODULE,
  };