[PATCH] net: sched: do not emit messages while holding spinlock

[PATCH] net: sched: do not emit messages while holding spinlock

[Li RongQing]

move messages emitting out of sch_tree_lock to avoid holding
this lock too long.

Signed-off-by: Li RongQing <lirongqing@baidu.com>
---
 net/sched/sch_htb.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/net/sched/sch_htb.c b/net/sched/sch_htb.c
index 1ea9846cc6ce..2a4ab7caf553 100644
--- a/net/sched/sch_htb.c
+++ b/net/sched/sch_htb.c
@@ -1337,6 +1337,7 @@ static int htb_change_class(struct Qdisc *sch, u32 classid,
 	struct nlattr *tb[TCA_HTB_MAX + 1];
 	struct tc_htb_opt *hopt;
 	u64 rate64, ceil64;
+	int warn = 0;
 
 	/* extract all subattrs from opt attr */
 	if (!opt)
@@ -1499,13 +1500,11 @@ static int htb_change_class(struct Qdisc *sch, u32 classid,
 		cl->quantum = min_t(u64, quantum, INT_MAX);
 
 		if (!hopt->quantum && cl->quantum < 1000) {
-			pr_warn("HTB: quantum of class %X is small. Consider r2q change.\n",
-				cl->common.classid);
+			warn = -1;
 			cl->quantum = 1000;
 		}
 		if (!hopt->quantum && cl->quantum > 200000) {
-			pr_warn("HTB: quantum of class %X is big. Consider r2q change.\n",
-				cl->common.classid);
+			warn = 1;
 			cl->quantum = 200000;
 		}
 		if (hopt->quantum)
@@ -1519,6 +1518,10 @@ static int htb_change_class(struct Qdisc *sch, u32 classid,
 
 	sch_tree_unlock(sch);
 
+	if (warn)
+		pr_warn("HTB: quantum of class %X is %s. Consider r2q change.\n",
+			    cl->common.classid, (warn == -1 ? "small" : "big"));
+
 	qdisc_class_hash_grow(sch, &q->clhash);
 
 	*arg = (unsigned long)cl;
-- 
2.11.0

Re: [PATCH] net: sched: do not emit messages while holding spinlock

[David Miller]

From: Li RongQing <lirongqing@baidu.com>
Date: Fri, 30 Mar 2018 10:11:21 +0800

> move messages emitting out of sch_tree_lock to avoid holding
> this lock too long.
> 
> Signed-off-by: Li RongQing <lirongqing@baidu.com>

Applied.