From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lb0-x22c.google.com (mail-lb0-x22c.google.com [IPv6:2a00:1450:4010:c04::22c]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.bufferbloat.net (Postfix) with ESMTPS id E77C53B2AE for ; Sat, 28 May 2016 22:32:45 -0400 (EDT) Received: by mail-lb0-x22c.google.com with SMTP id mp7so433394lbb.2 for ; Sat, 28 May 2016 19:32:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:subject:from:in-reply-to:date :content-transfer-encoding:message-id:references:to; bh=1nit/42ppRtNHD5U9ftv1Xj71ROvEb483eOCe+8mFTA=; b=klLzOOfI44xVcGLOhmnvx+t+dVD25S2CkdTJAwyMrjt4Klk3oXpgRx5X4e1IKS+seE vDt/WEtzbCnz7obS2oXa+OncUmdlzTY2qG6svw5CuStMPHqg8f2WTb4rg2gI9P+GJAH5 bD+lytAxIkF3gXIjmWWomvMD+8KOdTiodVB2W7bM65D7RG6lSGCCYF8i7WaVSHJbCu/8 QpsduNeAFv93PhrXf66DmET2OM1ENIWaSehY5bIzp+oSciCLAuDzNfTb2pMG4uNh9zRr /4oK0SapgERm80pyCuW3eJTT0srBR4xVS7tA3KHYgHnFH6DML92j9ujhadtD1YW5n467 ZadQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:subject:from:in-reply-to:date :content-transfer-encoding:message-id:references:to; bh=1nit/42ppRtNHD5U9ftv1Xj71ROvEb483eOCe+8mFTA=; b=QjUTXXJpF4tetWRGbuPda7kTxEztrE5iZ97baJqikL9s6qSeY3eGGR/PIscZQJb06y eccu4+sxyS0ookacWJgpDs/jpX7ap0ZxsfX748GMRVlWxO5HVBLUHMejDnYTmENd14HR BO1kU+aJcLV8xBEEJRSDh35Fw3sOX6bh/jdRDwv7m0v9NZeghVdoebZad87E0sf6IG3O fm6NFRnO18p2lrIts1jUYfUu17WgktOfbSjB0jsVEeOUEkepDksuanU/uWg5fKWiK0ZS +nylClDUJsBSyU4UFPOl/r4ufyAxvQNtdtmigR/jcrKBPUkNuhXi8uBCmRfjglqNeGCb Fdtw== X-Gm-Message-State: ALyK8tK5tN8Nt0LyeYhkAkDEv7cS+4g/9wXmxF+H3saGdwgHQUjZ5OM504LrX9Z93Qxt+g== X-Received: by 10.112.76.102 with SMTP id j6mr6710625lbw.98.1464489164505; Sat, 28 May 2016 19:32:44 -0700 (PDT) Received: from bass.home.chromatix.fi (188-67-138-144.bb.dnainternet.fi. [188.67.138.144]) by smtp.gmail.com with ESMTPSA id l10sm3908069lbw.38.2016.05.28.19.32.37 for (version=TLSv1/SSLv3 cipher=OTHER); Sat, 28 May 2016 19:32:43 -0700 (PDT) Content-Type: text/plain; charset=utf-8 Mime-Version: 1.0 (Mac OS X Mail 9.3 \(3124\)) From: Jonathan Morton In-Reply-To: Date: Sun, 29 May 2016 05:32:22 +0300 Content-Transfer-Encoding: quoted-printable Message-Id: References: To: cake@lists.bufferbloat.net X-Mailer: Apple Mail (2.3124) Subject: Re: [Cake] Heaps of cake 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: Sun, 29 May 2016 02:32:46 -0000 > On 21 May, 2016, at 01:07, Jonathan Morton = wrote: >=20 > Please do hammer on these codepaths for all you=E2=80=99re worth. It = compiles and survives a smoke-test, that=E2=80=99s all I know so far. Having noted a series of kernel panics in cake_drop(), I eventually = traced the fault to dequeue_head(), which AFAIK hadn=E2=80=99t been = touched since the first version (as it was lifted from fq_codel). If = it=E2=80=99s called on en empty subqueue, it tried to read NULL->next. The question remains why cake_drop() would select an empty subqueue as = the longest one - evidently there=E2=80=99s a missing heap update = somewhere. But at least now it won=E2=80=99t crash if that happens. - Jonathan Morton