From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ej1-f47.google.com (mail-ej1-f47.google.com [209.85.218.47]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id BCD101867 for ; Wed, 20 Apr 2022 16:40:04 +0000 (UTC) Received: by mail-ej1-f47.google.com with SMTP id y20so4698881eju.7 for ; Wed, 20 Apr 2022 09:40:04 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=tessares-net.20210112.gappssmtp.com; s=20210112; h=message-id:date:mime-version:user-agent:subject:content-language:to :references:from:in-reply-to:content-transfer-encoding; bh=REoJQXaR4ZPCfJjNlzUk3Y2yHafWckIDgtbtMpmxDWI=; b=uY+If7PrDHa4Z1xtaZSAFzBAlOKHi5s/wVQcIlySYdioNhZCh/FyMHdNOCwmTqvQYC jV8uKIZY+cM0MfOfbQB3BIZWWMEHSIYASCkMg9PpY5DuI6hjvAkDSqsT4t9wdXLU6ljZ mEESN2pKwQ0SMYZW3pLOf3TEf0HcsRmGwqbNEGdjCAd+9PGh5js0okxoSLzP6DqOnT7o A1aeSP75DEk96gisNPhF8brhT01ZSlwD5YVUI6xzjrSzful63lAqHrjbIpWYwNd1FMgg /wZJjnbEYjklVCD/QgYEGxUo/9V7/1G5MHk94zr2D28htDKnDCJ+Jok/hfR0YirIq7xg s4yQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:date:mime-version:user-agent:subject :content-language:to:references:from:in-reply-to :content-transfer-encoding; bh=REoJQXaR4ZPCfJjNlzUk3Y2yHafWckIDgtbtMpmxDWI=; b=MAIDUqAeBHDrMtIMB47A2ql1vif6RIo2k1/hoZh6sbVDD5cw6Fe6qGCvZxN3sGl7Qg Z2JmmILjcVhBLL8Q1nimQ2wotF/Qd0iFTwQ+kAO+RPGuRHFYtTuO5qymTEQBkywUmgrv objFnkGPLBifbepGL6Y8jtTqto6Cnvh3XEuPIDLiZD3Eqp2UhiQUHwPcxAVGEp7Ba449 GKv1AhdmwkLzWx+BDZknFzJlguek3LIh11XG5FEheYssRCaolAU1kJWkvn8kQKsAkSh6 BZT1fAUgkUvN6IwtrGXhGy8J0Ur66uFy8EUM7dx/fJBRiP7f5RLSBjPYPPv+RKhnqOau k7Wg== X-Gm-Message-State: AOAM533LW6mAASB9Jw5nW3AP+aHsavZIM5AO9K0EidEOQkwD9AoPMlAP rwepFe3bWxiw4MROPWMGBhJ06WyPYIRXOw== X-Google-Smtp-Source: ABdhPJw8mxvhep/CRnkQk6UYQA/tEOPaBVJvo2DHEQ3SV6K0OHnCNFlhKeSlPHQZ2LTfboUVl0+McA== X-Received: by 2002:a17:907:7b84:b0:6e8:b8c2:6fe2 with SMTP id ne4-20020a1709077b8400b006e8b8c26fe2mr20058922ejc.401.1650472802985; Wed, 20 Apr 2022 09:40:02 -0700 (PDT) Received: from ?IPV6:2a02:578:8593:1200:a8ef:af16:f14e:5d01? ([2a02:578:8593:1200:a8ef:af16:f14e:5d01]) by smtp.gmail.com with ESMTPSA id kw3-20020a170907770300b006d2a835ac33sm6865482ejc.197.2022.04.20.09.40.01 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 20 Apr 2022 09:40:01 -0700 (PDT) Message-ID: Date: Wed, 20 Apr 2022 18:40:00 +0200 Precedence: bulk X-Mailing-List: mptcp@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.8.0 Subject: Re: [PATCH mptcp-next v12 08/10] mptcp: add call_me_again flag Content-Language: en-GB To: Geliang Tang , mptcp@lists.linux.dev References: <68fa62e5d0ba5fe88f89f6be7923eb952fe3b817.1650430389.git.geliang.tang@suse.com> From: Matthieu Baerts In-Reply-To: <68fa62e5d0ba5fe88f89f6be7923eb952fe3b817.1650430389.git.geliang.tang@suse.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Hi Geliang, On 20/04/2022 06:57, Geliang Tang wrote: > For supporting a "redundant" packet scheduler in the future, this patch > adds a flag named call_me_again to indicate that get_subflow() function > needs to be called again. If I'm not mistaken, in mptcp.org, there are two functions that can be modified by a packets scheduler: - get_subflow(): return an ssk to where an skb passed in argument will be sent. A boolean is also passed to inform if it is a zero window test - next_segment(): return the next skb to be sent. A parameter called "reinject" can be set to 3 values: from reinject queue (1), from sent queue (0), meta-level retransmission for optimisations purposes (-1). In short, a redundant scheduler will then make sure the same skb is returned multiple times in next_segment(). (After the first time, 'reinject' is set to -1.) I understand it is quite different from what we currently have here in upstream where we don't really have a "next_segment()" that can be modified by the different schedulers. Having this 'call_me_again' variable should do the job and it is quite "flexible". At least more than setting a function parameter. But I don't know if it is a proper way and if it will fix all situations. I didn't follow the development on all different packet schedulers in mptcp.org. Maybe we can check with Christoph if we need to "fix an API". Cheers, Matt -- Tessares | Belgium | Hybrid Access Solutions www.tessares.net