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Miller" , Eric Dumazet , Paolo Abeni , Maciej Fijalkowski , Larysa Zaremba , Yunsheng Lin , Alexander Duyck , Jesper Dangaard Brouer , "Ilias Apalodimas" , , References: <20230629152305.905962-1-aleksander.lobakin@intel.com> <20230701170155.6f72e4b8@kernel.org> <72658bca-c2b2-b3cb-64a0-35540b247a11@intel.com> <20230703115734.6ee8f658@kernel.org> From: Alexander Lobakin In-Reply-To: <20230703115734.6ee8f658@kernel.org> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-ClientProxiedBy: FR2P281CA0069.DEUP281.PROD.OUTLOOK.COM (2603:10a6:d10:9a::10) To DM6PR11MB3625.namprd11.prod.outlook.com (2603:10b6:5:13a::21) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: DM6PR11MB3625:EE_|PH7PR11MB7499:EE_ X-MS-Office365-Filtering-Correlation-Id: 244aa836-6cb7-4333-5d79-08db7d53e89c X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0; X-Microsoft-Antispam-Message-Info: 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 X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:DM6PR11MB3625.namprd11.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230028)(346002)(376002)(136003)(366004)(39860400002)(396003)(451199021)(82960400001)(54906003)(478600001)(6486002)(6666004)(41300700001)(8936002)(8676002)(6916009)(38100700002)(4326008)(66946007)(66556008)(66476007)(316002)(2616005)(186003)(6512007)(6506007)(26005)(31696002)(86362001)(7416002)(5660300002)(2906002)(36756003)(31686004)(43740500002)(45980500001);DIR:OUT;SFP:1102; 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Usage of plain >> kfree_skb() is not allowed in the TH :s > > I haven't looked at the code so I could be lying but I thought that > the only thing that can't run in hard IRQ context is the destructor, > so if the caller knows there's no destructor they can free the skb. > > I'd ask you the inverse question. If the main use case is skb xdp > (which eh, uh, okay..) then why not make it use napi_consume_skb()? Remember about Wi-Fi, DSA, and other poor citizens with no native XDP! :D That was mostly a joke, but I thought of this, too. At the end my thought was "let's try making it cover more usecases" and I found this approach. I'm not saying it's optimal or even much needed, that's why I sent it to discuss basically. (e.g. I wanted to try speed up xdp_return_frame{,_bulk}() using it) > I don't think skb XDP can run in hard IRQ context, can it? skb XDP can't happen in the TH and I think we could assume it's safe to use napi_consume_skb() there (with a fake non-zero budget :p). > >> Anyway, if the flag really makes no sense, I can replace it with >> in_softirq(), it's my hobby to break weird drivers :D Thanks, Olek