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[2a0c:4d80:42:443::2]) by smtp.gmail.com with ESMTPSA id a640c23a62f3a-b86f0d6d7c6sm1037956666b.42.2026.01.13.06.32.21 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 13 Jan 2026 06:32:21 -0800 (PST) Received: by alrua-x1.borgediget.toke.dk (Postfix, from userid 1000) id 739F240894F; Tue, 13 Jan 2026 15:32:18 +0100 (CET) From: =?UTF-8?q?Toke=20H=C3=B8iland-J=C3=B8rgensen?= To: =?UTF-8?q?Toke=20H=C3=B8iland-J=C3=B8rgensen?= , Jamal Hadi Salim , Cong Wang , Jiri Pirko Cc: =?UTF-8?q?Toke=20H=C3=B8iland-J=C3=B8rgensen?= , Paolo Abeni , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Simon Horman , cake@lists.bufferbloat.net, netdev@vger.kernel.org Subject: [PATCH net-next] net/sched: cake: avoid separate allocation of struct cake_sched_config Date: Tue, 13 Jan 2026 15:31:56 +0100 Message-ID: <20260113143157.2581680-1-toke@redhat.com> X-Mailer: git-send-email 2.52.0 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Paolo pointed out that we can avoid separately allocating struct cake_sched_config even in the non-mq case, by embedding it into struct cake_sched_data. This reduces the complexity of the logic that swaps the pointers and frees the old value, at the cost of adding 56 bytes to the latter. Since cake_sched_data is already almost 17k bytes, this seems like a reasonable tradeoff. Suggested-by: Paolo Abeni Signed-off-by: Toke Høiland-Jørgensen --- net/sched/sch_cake.c | 29 ++++++----------------------- 1 file changed, 6 insertions(+), 23 deletions(-) diff --git a/net/sched/sch_cake.c b/net/sched/sch_cake.c index e30ef7f8ee68..fd56b7d88301 100644 --- a/net/sched/sch_cake.c +++ b/net/sched/sch_cake.c @@ -221,6 +221,7 @@ struct cake_sched_data { struct tcf_block *block; struct cake_tin_data *tins; struct cake_sched_config *config; + struct cake_sched_config initial_config; struct cake_heap_entry overflow_heap[CAKE_QUEUES * CAKE_MAX_TINS]; @@ -2798,8 +2799,6 @@ static void cake_destroy(struct Qdisc *sch) qdisc_watchdog_cancel(&q->watchdog); tcf_block_put(q->block); kvfree(q->tins); - if (q->config && !q->config->is_shared) - kvfree(q->config); } static void cake_config_init(struct cake_sched_config *q, bool is_shared) @@ -2822,13 +2821,9 @@ static int cake_init(struct Qdisc *sch, struct nlattr *opt, struct netlink_ext_ack *extack) { struct cake_sched_data *qd = qdisc_priv(sch); - struct cake_sched_config *q; + struct cake_sched_config *q = &qd->initial_config; int i, j, err; - q = kzalloc(sizeof(*q), GFP_KERNEL); - if (!q) - return -ENOMEM; - cake_config_init(q, false); sch->limit = 10240; @@ -2842,14 +2837,13 @@ static int cake_init(struct Qdisc *sch, struct nlattr *opt, if (opt) { err = cake_change(sch, opt, extack); - if (err) - goto err; + return err; } err = tcf_block_get(&qd->block, &qd->filter_list, sch, extack); if (err) - goto err; + return err; quantum_div[0] = ~0; for (i = 1; i <= CAKE_QUEUES; i++) @@ -2857,10 +2851,8 @@ static int cake_init(struct Qdisc *sch, struct nlattr *opt, qd->tins = kvcalloc(CAKE_MAX_TINS, sizeof(struct cake_tin_data), GFP_KERNEL); - if (!qd->tins) { - err = -ENOMEM; - goto err; - } + if (!qd->tins) + return -ENOMEM; for (i = 0; i < CAKE_MAX_TINS; i++) { struct cake_tin_data *b = qd->tins + i; @@ -2893,22 +2885,13 @@ static int cake_init(struct Qdisc *sch, struct nlattr *opt, qd->last_checked_active = 0; return 0; -err: - kvfree(qd->config); - qd->config = NULL; - return err; } static void cake_config_replace(struct Qdisc *sch, struct cake_sched_config *cfg) { struct cake_sched_data *qd = qdisc_priv(sch); - struct cake_sched_config *q = qd->config; qd->config = cfg; - - if (!q->is_shared) - kvfree(q); - cake_reconfigure(sch); } -- 2.52.0