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[2a00:7660:6da:10::2]) by smtp.gmail.com with ESMTPSA id l20sm4219975edd.96.2019.04.05.03.28.22 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Fri, 05 Apr 2019 03:28:22 -0700 (PDT) Received: by alrua-x1.borgediget.toke.dk (Postfix, from userid 1000) id 0AC131804A6; Fri, 5 Apr 2019 12:28:22 +0200 (CEST) From: Toke =?utf-8?q?H=C3=B8iland-J=C3=B8rgensen?= To: Greg Kroah-Hartman Cc: David Miller , stable@vger.kernel.org, cake@lists.bufferbloat.net Date: Fri, 05 Apr 2019 12:28:22 +0200 Message-ID: <155446010198.1460.1169444436924215431.stgit@alrua-x1> In-Reply-To: <155446010188.1460.16734711102827171744.stgit@alrua-x1> References: <155446010188.1460.16734711102827171744.stgit@alrua-x1> User-Agent: StGit/unknown-version MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Subject: [Cake] [PATCH for-4.19 1/3] sch_cake: Simplify logic in cake_select_tin() X-BeenThere: cake@lists.bufferbloat.net X-Mailman-Version: 2.1.20 Precedence: list List-Id: Cake - FQ_codel the next generation List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 05 Apr 2019 10:28:25 -0000 commit 4b454433221de445f6d3d73b0ac27b4f7da25b83 upstream. The logic in cake_select_tin() was getting a bit hairy, and it turns out we can simplify it quite a bit. This also allows us to get rid of one of the two diffserv parsing functions, which has the added benefit that already-zeroed DSCP fields won't get re-written. Suggested-by: Kevin Darbyshire-Bryant Signed-off-by: Toke Høiland-Jørgensen --- net/sched/sch_cake.c | 44 ++++++++++++++++---------------------------- 1 file changed, 16 insertions(+), 28 deletions(-) diff --git a/net/sched/sch_cake.c b/net/sched/sch_cake.c index 793016d722ec..640f00e9f665 100644 --- a/net/sched/sch_cake.c +++ b/net/sched/sch_cake.c @@ -1508,20 +1508,6 @@ static unsigned int cake_drop(struct Qdisc *sch, struct sk_buff **to_free) return idx + (tin << 16); } -static void cake_wash_diffserv(struct sk_buff *skb) -{ - switch (skb->protocol) { - case htons(ETH_P_IP): - ipv4_change_dsfield(ip_hdr(skb), INET_ECN_MASK, 0); - break; - case htons(ETH_P_IPV6): - ipv6_change_dsfield(ipv6_hdr(skb), INET_ECN_MASK, 0); - break; - default: - break; - } -} - static u8 cake_handle_diffserv(struct sk_buff *skb, u16 wash) { u8 dscp; @@ -1553,25 +1539,27 @@ static struct cake_tin_data *cake_select_tin(struct Qdisc *sch, { struct cake_sched_data *q = qdisc_priv(sch); u32 tin; + u8 dscp; - if (TC_H_MAJ(skb->priority) == sch->handle && - TC_H_MIN(skb->priority) > 0 && - TC_H_MIN(skb->priority) <= q->tin_cnt) { + /* Tin selection: Default to diffserv-based selection, allow overriding + * using firewall marks or skb->priority. + */ + dscp = cake_handle_diffserv(skb, + q->rate_flags & CAKE_FLAG_WASH); + + if (q->tin_mode == CAKE_DIFFSERV_BESTEFFORT) + tin = 0; + + else if (TC_H_MAJ(skb->priority) == sch->handle && + TC_H_MIN(skb->priority) > 0 && + TC_H_MIN(skb->priority) <= q->tin_cnt) tin = q->tin_order[TC_H_MIN(skb->priority) - 1]; - if (q->rate_flags & CAKE_FLAG_WASH) - cake_wash_diffserv(skb); - } else if (q->tin_mode != CAKE_DIFFSERV_BESTEFFORT) { - /* extract the Diffserv Precedence field, if it exists */ - /* and clear DSCP bits if washing */ - tin = q->tin_index[cake_handle_diffserv(skb, - q->rate_flags & CAKE_FLAG_WASH)]; + else { + tin = q->tin_index[dscp]; + if (unlikely(tin >= q->tin_cnt)) tin = 0; - } else { - tin = 0; - if (q->rate_flags & CAKE_FLAG_WASH) - cake_wash_diffserv(skb); } return &q->tins[tin];