From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from BN8PR05CU002.outbound.protection.outlook.com (mail-eastus2azon11011056.outbound.protection.outlook.com [52.101.57.56]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5481D282F12; Mon, 24 Aug 2026 10:48:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=52.101.57.56 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787568503; cv=fail; b=SlMMuaiDNtuqKj2yHtuXsKedhBWcxb1wP+uZXIiml3vt+2dsCBhwM9dyljgWQ+Z7D4Dt5ApjD4OErIRr6+ourcOrtgiMA95VlMm5h4zaxR35hyDxUUZ3LTHjxbjZCOpj4c/so52YEALLoRYUg/niuTNONDRP/g0aFu/RhxIZNhs= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787568503; c=relaxed/simple; bh=Jy2E5J7xdi4V0lQxoFamVUfPUCqEuTjjd+TqB6LRMFY=; h=Message-ID:Date:Subject:To:Cc:References:From:In-Reply-To: Content-Type:MIME-Version; b=KmAsU18V/h+hhcjT4CZbNVPqT44anCQp7rl+GLDjW+0AlfNTtustB1RAlAccA4+0BPIEqPlGT9QypVArOK4VIXRyUN3j2Ag+7UHnaHzieZppBk0RwwZqREhk8rgojTFazGANSCnFfc3fCZWrpDeqF4ciTgj+FTZcruXVuRWsu3A= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=nvidia.com; spf=fail smtp.mailfrom=nvidia.com; dkim=pass (2048-bit key) header.d=Nvidia.com header.i=@Nvidia.com header.b=otvCfM8n; arc=fail smtp.client-ip=52.101.57.56 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=nvidia.com Authentication-Results: smtp.subspace.kernel.org; spf=fail smtp.mailfrom=nvidia.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=Nvidia.com header.i=@Nvidia.com header.b="otvCfM8n" ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=I9CC7ge4zURTMH9LFb/LYPDQksS1G+cxKImvW6OI8rPKuDn4GnNgjEL8hBiQOdfzyV66undCj2Me0wHeXufb2K6ilLTSM8/kLsPPAym+N1C+LzndFZ11703A3vDBAIR4a4FNUleDrZGXNq+Q7G0J7XUBOFeGrfrFnIETRiNdlGCkuwTqLLnfMOsoH1dxcPHzPNXArdF7PPfbdYWzSb6X+sFbWnILEV1m2EvKMA0/JiGexquZEbN2Zw20F8LSNXyVfvCJrYwkZ0CN4AUgJdFjsdKWrCB8nVWMCAJp8X4Xiy28KdGywnq3BIZFRufCQaXf2hzaL1b8nbMGzkDOIGevcg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector10001; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=kGM8YvRWqjFqBuQlY/QeDKxAeedk5yZDuPKLFP3ZqKk=; b=oWnRYal7fG0CexORHi7fQ3PsFCV9SEsDYqqoZliT2Ka2iWeIlraLJZa49/AnHPeHisFQYYk0en8lUlcootwW5Cg/+RFt1KREV03d7gGFSYrba81H6JpmU53xDWR+vC4FAgguPKLsxjEJ3YQADlX32Zxn1guL+ktNbbHCchMdqlxIUzxyaKHWHVrz3IsZKXCTe1QpNvnk35G03pcPXIy7f13hbkVCxWfSTcj4Xd9mUDzwVAGVWlpNzkIimFkHWM9DrLRgeB9RonSu5qhxRUPQPcSS3B4IOocAs5EeNrpmPxz3eSHnEmK1FdXUGswNPV+qwVszphXx2KIjqScp9kqlvw== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=nvidia.com; dmarc=pass action=none header.from=nvidia.com; dkim=pass header.d=nvidia.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=Nvidia.com; s=selector2; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=kGM8YvRWqjFqBuQlY/QeDKxAeedk5yZDuPKLFP3ZqKk=; b=otvCfM8ntZh0JofDvGKFTzd1YDvsJY3rDsYOJXetjRDiW5mN/kCx6IPoq4YbGZnfGZeH1lIdyTMN+BOp43wmJtn1aJjwCSbn4Ol1R9j4oG1BP71+Q+5AZpEFZfshGpm88Rtg4Yh7/66kUn+O6RmQTw32tZkq9ByBB6wV0QW6L+CMK+/rYwPlv7RLhg27tosieTTVMydEfAoHQ94SsHfxpNbK7I3WNAGugEo3uR5ZYf1fSbiJTnHHRKjFnzyvpx6M+gvN1AToi3z4LDPs5B0kAP/EaDgEtAHvDGbO4gpq12TQKzJdJPJjuMkwJZC7icAI3GU3I80DspDKHogH0nFKXg== Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=nvidia.com; Received: from CH3PR12MB8728.namprd12.prod.outlook.com (2603:10b6:610:171::12) by CH2PR12MB4245.namprd12.prod.outlook.com (2603:10b6:610:af::15) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.21.339.12; Mon, 24 Aug 2026 10:48:16 +0000 Received: from CH3PR12MB8728.namprd12.prod.outlook.com ([fe80::2641:1046:bdf3:93d7]) by CH3PR12MB8728.namprd12.prod.outlook.com ([fe80::2641:1046:bdf3:93d7%6]) with mapi id 15.21.0339.012; Mon, 24 Aug 2026 10:48:16 +0000 Message-ID: Date: Mon, 24 Aug 2026 12:48:10 +0200 User-Agent: Mozilla Thunderbird Beta Subject: Re: [PATCH net v3 2/2] net/mlx5e: Prevent stale XSK buffer release on MPWQE refill retry To: Jerome Tollet , netdev@vger.kernel.org Cc: saeedm@nvidia.com, tariqt@nvidia.com, mbloch@nvidia.com, leonro@nvidia.com, daniel@iogearbox.net, andrew+netdev@lunn.ch, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, ast@kernel.org, hawk@kernel.org, john.fastabend@gmail.com, sdf@fomichev.me, linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org, bpf@vger.kernel.org, stable@vger.kernel.org References: <20260820151558.11015-1-jtollet@cisco.com> <675ce8a404cfe305e788a8e273b4091c9a90f867.1787347981.git.jtollet@cisco.com> Content-Language: en-US From: Dragos Tatulea In-Reply-To: <675ce8a404cfe305e788a8e273b4091c9a90f867.1787347981.git.jtollet@cisco.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-ClientProxiedBy: FR2P281CA0075.DEUP281.PROD.OUTLOOK.COM (2603:10a6:d10:9a::17) To CH3PR12MB8728.namprd12.prod.outlook.com (2603:10b6:610:171::12) Precedence: bulk X-Mailing-List: linux-rdma@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: CH3PR12MB8728:EE_|CH2PR12MB4245:EE_ X-MS-Office365-Filtering-Correlation-Id: f97cb439-452f-404f-96cf-08df01cd3409 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|376014|7416014|1800799024|366016|23010399003|10067099003|56012099006|11063799006|4143699003|18002099003|22082099003; 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:CH3PR12MB8728.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(376014)(7416014)(1800799024)(366016)(23010399003)(10067099003)(56012099006)(11063799006)(4143699003)(18002099003)(22082099003);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?UU4ydHZ5NmJQTmE0UWRjWjN6SDhFdW4yV3RwKzJoRjBKWkhvc3Y2RWc5cDBD?= =?utf-8?B?MGhMWEFRTUtPcm9QQ0FndEVVNjY3TU9qM3N4NVFaeUJHeHNJMi9Ea2ZyWkZp?= =?utf-8?B?MkgxNlpzYmZ1VWJ1cnQyTWxYQXYwNkZhS2JQcnYrOFpCU0F3T21PUThyUzk3?= =?utf-8?B?a0JyTzdkVjNTQ3ZhOW5YYThsOXhuTmVCRWhtcVRLWFZURGNVUmNSbTRWWlRV?= =?utf-8?B?OTUvdXJ5VUdEMWJaeE1hMG5WekcyUDA1enUzREZEc1gxQUxOYWRZcGQvQ0Vu?= =?utf-8?B?UXZKNlpLVG9vU0FWMFI5aHJsY0d1N2M0NEVIamY1ZTFTRzBJcUpWUWVxQm1K?= =?utf-8?B?elhSajJ5SzhjZjk2bXZJMDZrbkh5dGJCVmpwaytaWS9qQjNiTzNMMVRVUW9U?= =?utf-8?B?aGFmaGJsM3h6dUZrZW0yRlRmTmxzbTgzREZ6cGJ0M0ZQNS91M1MvdWF0L1FZ?= =?utf-8?B?di9EYU96NzJSV2I3ZWRjY3V0UnA4TEx2MHZuZ1FQaGxVUjhkNXJqOGZhY1M5?= =?utf-8?B?SHJOVkozbWtnTXppV3FrWWZmMyttY09DdkxNaW9YV1QxYUxGWThzdUFPNXZm?= =?utf-8?B?bVRsRFRjcHNkTS9DTEZOdUhZM29SSHF6d2kyZlRWUlJNRG5ZaGxpSTRyQStM?= =?utf-8?B?ZFBhaVZoYmpZclZUd1IzNnZJTVI4SlQ3OGdTc21kWUR0dHVIOWVjZmpoaEJ1?= =?utf-8?B?OGE5NnI3aU00TEFRSjg4d3B0QlpkVUEvd1F6ejhKZ3hpK0t0THRkQkNOeDBY?= =?utf-8?B?K2t2emtRTHZJc3ZWUjM5aWFmWVdGVVhFLzVCZFg2SnlHNUN3Q1QyaXc5UVla?= =?utf-8?B?OHJuMGE4blE0SkVLMmxlT2hrWi95M1M5U3hUOVZmZ0dIci9LQWxrUGlITjg1?= =?utf-8?B?KzQxRHVPbW5JSzVxZmd5dVZZanp5cTFsZXRHMlFjUXVpNE9jS1V2S0VGUExp?= =?utf-8?B?M3VhYmszSWxkb3c5NkVXeTFxR0lHY0laaG81bjh6eXNKaDZtYlVVUThFRXR2?= =?utf-8?B?aDJILzhJMkxMOEg0cTRIemR0c1ExaS9tOFZzMFlnSzREbzkyT0pFQnlMRnc3?= =?utf-8?B?SEwwRFYzVzM4ekNZOU8xOEV1cUhzVllkaStMaVdhcC9PdFZGcGhNYSsyQTR3?= =?utf-8?B?ZGpnaXJPQ251QU5KZnRXWllsQVM5aFBDTmxLamhrdWhVMDdsd0ZpcDlQRW9P?= =?utf-8?B?c1JhVzZMY2xtV1hwT1FRY3RueDUrMlh5amxuSkZOVjVEcnNYNCtNUjIvQmp2?= =?utf-8?B?Tk4yMkJuUTBBSjRvNmJPZ2pxRGJITVNMRzZIa1BUVVEzQTBOSVVEMGx0SmFp?= =?utf-8?B?UG5QMWdnQkM0OEpPTUlRb0hIL3kxYUxnL1d2TFRDMTFxczlSQzBMcXNjejNE?= =?utf-8?B?ek9DTXpBWFIyc0lQK0IxZGZpM2JGRy84bit5UG5keHVkNm8wTDdETkFreUpo?= =?utf-8?B?WStiOUh6L2xsK0lBMFBCUzNLU1ArYU53RXNIU1VJYk1mSDFKdCtaMFFGNFBC?= =?utf-8?B?RHN4eDdNcS9pYTJsT2VoOFVUY3FtTVVmNTNQODRkZFVnQWRONGdpZHZlVTl4?= =?utf-8?B?VFFLZmRTbXNraGxXL2RCUTErcjdVMkxhQXV3cm5RSW04TG5wMnRtVVp3eUg1?= =?utf-8?B?QnBCMERJQk9VOTVRbEpJek10MStZczlkUXdYclQrYnVOdVowMjVUL29IRkRh?= =?utf-8?B?Mmd2cHlWZzJ1ZjZRZ0JpMXliU2xTSjkvU29TV1U3Y3I5SDZwaFEvV2tIVHQ2?= =?utf-8?B?ck52a2taMjVPUExROHM0ZjFxTy9nVGhYZkJyN2NLK1RCUktRVU5xQ1g0Qk1F?= =?utf-8?B?R1J3S09ib08vQml5TmZpSXA5c3ZxdWxCVDJ4S3N5d0RkaHVLQ0NZOW1kckV4?= =?utf-8?B?QnR5MDcxL1JyazR5aldYYllWNVliRkhCVmRVQkhPWjgrZEhkLzFwSk16c3po?= =?utf-8?B?ZURxY3JLTStjM2I0KzZEMlYxdHR0TElIcGlSQnJxeFJKT3U5TXptUzlkRmxT?= =?utf-8?B?dVBQdGVJZ2lpNHVpTm9MSFo4TFBOOHBvb2hRaTRsajVEd2pjYjJxZ0Zpcml6?= =?utf-8?B?TGpaMDVFaHdPSjZweDFRT2x6ZUJOekd0NHY3eHNwQnZGeUFyei9pMld0L1Z5?= =?utf-8?B?UVluWHFtRUs5MkdrcjhVSUxleXQwSERxWEtZVFZQZFdwdXpML2ZMaFgrSGNy?= =?utf-8?B?WVdzZkhFNXQrY3JDaTB5MkZtZVB0TVZzZmJ6OE1OdUhNT3NRWjVjd0s5OFF4?= =?utf-8?B?MnVrdHIvUUhQSisrQ3NLYkZ2SEFUdXNFOGYwWnp4UkxlRTRyclY3aXRDUFEx?= =?utf-8?B?YjNibG9LcXdmUnB6cFFiZThXdGEwU2s5Z2FIeEZrd2h6M3VIYXBQdz09?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: f97cb439-452f-404f-96cf-08df01cd3409 X-MS-Exchange-CrossTenant-AuthSource: CH3PR12MB8728.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 24 Aug 2026 10:48:16.5314 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: a8ur94K9ptIIHdBw6+cL4TVa67W1lj51fR5TI8Yj3n2VTg22qGG4OlxXX8LJO7HsIkJSH9R/HoDg9uNhWXZoNw== X-MS-Exchange-Transport-CrossTenantHeadersStamped: CH2PR12MB4245 On 21.08.26 23:37, Jerome Tollet wrote: > With AF_XDP on a striding RQ, mlx5e defers releasing XSK buffers until > an MPWQE is refilled. If XSK allocation then returns -ENOMEM, > actual_wq_head is not advanced and a later NAPI poll retries the same > WQE. > > mlx5e_free_rx_mpwqe() currently leaves each released slot marked as > releasable. On retry it can therefore call xsk_buff_free() again through > stale pointers after the frames have returned to the XSK pool and been > reallocated. > > Mark each slot as released immediately after xsk_buff_free(). The > successful allocation path already clears the bitmap after replacing > all buffers, so retries become idempotent without changing the success > path. > > Fault injection forced three consecutive allocation failures for one > selected MPWQE in AF_XDP zero-copy mode. Stock freed the same 16 XSK > buffer pointers on all three attempts, for 48 frees. With this change, > only the initial 16 frees occurred; retries observed a full bitmap, and > a later successful allocation cleared it. > > Fixes: 4c2a13236807 ("net/mlx5e: RX, Defer page release in striding rq for better recycling") > Cc: stable@vger.kernel.org > Signed-off-by: Jerome Tollet > --- > drivers/net/ethernet/mellanox/mlx5/core/en_rx.c | 7 +++++-- > 1 file changed, 5 insertions(+), 2 deletions(-) > > diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c b/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c > index 7bd0606a5..5fe17d295 100644 > --- a/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c > +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_rx.c > @@ -609,9 +609,12 @@ mlx5e_free_rx_mpwqe(struct mlx5e_rq *rq, struct mlx5e_mpw_info *wi) > * is no way to return the page to userspace when the interface > * goes down. > */ > - for (i = 0; i < rq->mpwqe.pages_per_wqe; i++) > - if (no_xdp_xmit || !test_bit(i, wi->skip_release_bitmap)) > + for (i = 0; i < rq->mpwqe.pages_per_wqe; i++) { > + if (no_xdp_xmit || !test_bit(i, wi->skip_release_bitmap)) { > xsk_buff_free(xsk_buffs[i]); > + __set_bit(i, wi->skip_release_bitmap); > + } > + } > } else { > for (i = 0; i < rq->mpwqe.pages_per_wqe; i++) { > if (no_xdp_xmit || !test_bit(i, wi->skip_release_bitmap)) { I'd change this to be consistent with mlx5e_alloc_rx_mpwqe(): set skip_release_bitmap bits in error path of mlx5e_xsk_alloc_rx_mpwqe. Thanks, Dragos