[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-Id: <20230207135440.1482856-11-vladimir.oltean@nxp.com>
Date: Tue, 7 Feb 2023 15:54:35 +0200
From: Vladimir Oltean <vladimir.oltean@....com>
To: netdev@...r.kernel.org
Cc: "David S. Miller" <davem@...emloft.net>,
Eric Dumazet <edumazet@...gle.com>,
Jakub Kicinski <kuba@...nel.org>,
Paolo Abeni <pabeni@...hat.com>,
Jamal Hadi Salim <jhs@...atatu.com>,
Cong Wang <xiyou.wangcong@...il.com>,
Jiri Pirko <jiri@...nulli.us>,
Vinicius Costa Gomes <vinicius.gomes@...el.com>,
Kurt Kanzenbach <kurt@...utronix.de>,
Jacob Keller <jacob.e.keller@...el.com>,
Gerhard Engleder <gerhard@...leder-embedded.com>,
Jesse Brandeburg <jesse.brandeburg@...el.com>,
Tony Nguyen <anthony.l.nguyen@...el.com>,
intel-wired-lan@...ts.osuosl.org, linux-kernel@...r.kernel.org
Subject: [PATCH v2 net-next 10/15] net/sched: make stab available before ops->init() call
Some qdiscs like taprio turn out to be actually pretty reliant on a well
configured stab, to not underestimate the skb transmission time (by
properly accounting for L1 overhead).
In a future change, taprio will need the stab, if configured by the
user, to be available at ops->init() time. It will become even more
important in upcoming work, when the overhead will be used for the
queueMaxSDU calculation that is passed to an offloading driver.
However, rcu_assign_pointer(sch->stab, stab) is called right after
ops->init(), making it unavailable, and I don't really see a good reason
for that.
Move it earlier, which nicely seems to simplify the error handling path
as well.
Signed-off-by: Vladimir Oltean <vladimir.oltean@....com>
Reviewed-by: Kurt Kanzenbach <kurt@...utronix.de>
---
v1->v2: none
net/sched/sch_api.c | 29 +++++++++++------------------
1 file changed, 11 insertions(+), 18 deletions(-)
diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c
index c14018a8052c..e9780631b5b5 100644
--- a/net/sched/sch_api.c
+++ b/net/sched/sch_api.c
@@ -1282,12 +1282,6 @@ static struct Qdisc *qdisc_create(struct net_device *dev,
if (err)
goto err_out3;
- if (ops->init) {
- err = ops->init(sch, tca[TCA_OPTIONS], extack);
- if (err != 0)
- goto err_out5;
- }
-
if (tca[TCA_STAB]) {
stab = qdisc_get_stab(tca[TCA_STAB], extack);
if (IS_ERR(stab)) {
@@ -1296,11 +1290,18 @@ static struct Qdisc *qdisc_create(struct net_device *dev,
}
rcu_assign_pointer(sch->stab, stab);
}
+
+ if (ops->init) {
+ err = ops->init(sch, tca[TCA_OPTIONS], extack);
+ if (err != 0)
+ goto err_out5;
+ }
+
if (tca[TCA_RATE]) {
err = -EOPNOTSUPP;
if (sch->flags & TCQ_F_MQROOT) {
NL_SET_ERR_MSG(extack, "Cannot attach rate estimator to a multi-queue root qdisc");
- goto err_out4;
+ goto err_out5;
}
err = gen_new_estimator(&sch->bstats,
@@ -1311,7 +1312,7 @@ static struct Qdisc *qdisc_create(struct net_device *dev,
tca[TCA_RATE]);
if (err) {
NL_SET_ERR_MSG(extack, "Failed to generate new estimator");
- goto err_out4;
+ goto err_out5;
}
}
@@ -1321,6 +1322,8 @@ static struct Qdisc *qdisc_create(struct net_device *dev,
return sch;
err_out5:
+ qdisc_put_stab(rtnl_dereference(sch->stab));
+err_out4:
/* ops->init() failed, we call ->destroy() like qdisc_create_dflt() */
if (ops->destroy)
ops->destroy(sch);
@@ -1332,16 +1335,6 @@ static struct Qdisc *qdisc_create(struct net_device *dev,
err_out:
*errp = err;
return NULL;
-
-err_out4:
- /*
- * Any broken qdiscs that would require a ops->reset() here?
- * The qdisc was never in action so it shouldn't be necessary.
- */
- qdisc_put_stab(rtnl_dereference(sch->stab));
- if (ops->destroy)
- ops->destroy(sch);
- goto err_out3;
}
static int qdisc_change(struct Qdisc *sch, struct nlattr **tca,
--
2.34.1
Powered by blists - more mailing lists