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Sun, 29 May 2016 15:51:45 +0000 To: References: From: Kevin Darbyshire-Bryant Message-ID: <574B100F.8000307@darbyshire-bryant.me.uk> Date: Sun, 29 May 2016 16:51:43 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.8.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 8bit X-Originating-IP: [2001:470:183f:da2b::4007:25d] X-ClientProxiedBy: AM4PR0401CA0031.eurprd04.prod.outlook.com (10.167.83.41) To VI1PR07MB0942.eurprd07.prod.outlook.com (10.161.110.147) X-MS-Office365-Filtering-Correlation-Id: 6ee9313a-406b-46ef-0365-08d387d92372 X-Microsoft-Exchange-Diagnostics: 1; VI1PR07MB0942; 2:gJ6+FYkQceI7M7CBSrypD+I25wcXUFl0yG3Qpeff0aOKak5MYayGu2h+t3sG1VpEjcInDx+rJm9+CiWIQHpZx2TDDXIiKaJSo6qqK5H58J67BcsiBMVlt1VaghnZ2z1QsyUcI64qH4faLhXyg0HaHN1nBFbd4Awcc1vEMadgieJ7GtW2tMNFPe+2SdBObVwq; 3:zNuMs0shnFzTOaCgKRlVKCES9Uvk1SghWzjIHtGWDUfRH1CecjV8SOz6geVdEe2adoOeIo5XQsKy4Z0ELwbnzayARMD1WfKmzx7e9OFunhv0SJvmD7Z87yvE2cPiWBJi; 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VI1PR07MB0942; 5:gO4AYTUPQNV8nVBQF7xi4u+DQWv/41UwfLyacAuWedD/jHE05f4aMxifzXe0tG5DFQKriiJxxoietB2ccIz1MLKA0bhWEZZTfgfIZPfmj6Ws8LjDB1lfXrbXdVo4Ons9LA61ef9+zYmld50vjD7+0w==; 24:iZnvQHGJ78heMdUH/0yLeWm60t37Ms7sMemWb9w8A5dOuH6119yIEWuvzDssTzPKSYD5Mb5n55gLDxTyAVw50JTgHZ0rhNMrN1Pa22HpGcw=; 7:crXkj9Nl10384RL1VVPXHKzeZqKB9EjsmsgJ89GrUl+q0eeyaIuIOfn96LCfEzG0n+XDpSZ/34HCKb10SgDGv7fqYzYwimcQgP064ApQ4qTus/vuUE780WaP2uXDuAfoT/okqsKT+CL6cPKtxPrdHCmogtHm/VmYU3tOwW+yVtmUsCNKH+ZuJ62LF69j8oIV SpamDiagnosticOutput: 1:23 SpamDiagnosticMetadata: NSPM X-OriginatorOrg: darbyshire-bryant.me.uk X-MS-Exchange-CrossTenant-OriginalArrivalTime: 29 May 2016 15:51:45.9511 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-Transport-CrossTenantHeadersStamped: VI1PR07MB0942 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 15:51:49 -0000 On 29/05/16 03:32, Jonathan Morton wrote: > >> On 21 May, 2016, at 01:07, Jonathan Morton wrote: >> >> Please do hammer on these codepaths for all you’re worth. It compiles and survives a smoke-test, that’s 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’t been touched since the first version (as it was lifted from fq_codel). If it’s 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’s a missing heap update somewhere. But at least now it won’t crash if that happens. > > - Jonathan Morton Pointed my build at the latest code, so far no unexpected out-to-lunch moments :-) Thanks for continuing to work on making things stable again. Kevin