From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from YT6PR01CU002.outbound.protection.outlook.com (mail-canadacentralazon11022100.outbound.protection.outlook.com [40.107.193.100]) (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 875681925B8 for ; Sun, 19 Jan 2025 20:00:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=40.107.193.100 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737316848; cv=fail; b=jVIFnmw/hggKVewGwvH4VDNF9ZK2yThP+5npVlquRe1gzu3OFGocG0hvWScE4XQtnLHYrBnrH5g1R2YrHjj01FVhH/qaWof99Bl0jB9ki7+ZnOdXGwvS+6WcQx5SmwTZKRh5AlwwzaaTpzlQuEh8q4p1TSR5C69ihQRjcWaqd50= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737316848; c=relaxed/simple; bh=w8zJARQ/EDbLFMOVpAksfgCY6Ohka81iwM1lsvtq+54=; h=Date:From:To:Cc:Subject:Message-ID:References:Content-Type: Content-Disposition:In-Reply-To:MIME-Version; b=RokD3wf369U6zCo48Z3Me30yxfXpYEUJ43BkFVPMSy0GvLwl/JM+WRN5tNl0ANldoiS33hFuGKP87A/2RD3ih2MEBH3y+MYyyVzNrQ4boAnj026DKi987zBnSN2a34igI3veYYhOzzHNTpgjyI3KT8Yu9D4jL7dcFzp4Zu1BRAg= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=raithlin.com; spf=pass smtp.mailfrom=raithlin.com; dkim=pass (1024-bit key) header.d=raithlin.onmicrosoft.com header.i=@raithlin.onmicrosoft.com header.b=pJEOcwSF; arc=fail smtp.client-ip=40.107.193.100 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=raithlin.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=raithlin.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=raithlin.onmicrosoft.com header.i=@raithlin.onmicrosoft.com header.b="pJEOcwSF" ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=q9a8EAAcHs1Us6BhwAukT6r/HOyMOmwoc64riYdikIYLtCB1kIIMPAssUkdqs53HyC6oQibZQRP3CUWf/2XhJRSacrjchwHGC4nS/CzODLPiV8mbKs2QiUw59kLvoVI5jQrUUaLsgCalnWCUsHLVrd9XBV2wPQJ8B8JGh8kcms1uVRmrH8qIOqgi96M7lN/HIj1i3sdtL6cZXopyJ59eHi6zUyaqzGbpM/2BZqJQT3ugvmkcXoWcZKSdVRynpHSVA+A0ovjhjT4fhqWeHoAnA3WEloBsLNUD2jMJXSUfjNnonMcCuczehE8JLSsW5PxNDJbsvOJH75zLf274YnhTOg== 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=Udqkvc8NX5f5el6Fsy20PXTJmhDnGWGAWxt7iSrETnw=; b=uxqISBi92M63oidIQYOd/Kx98jSzSmOPZ/iXukGR5II2uPwUb/4J0E4ggwwK4v0nDfdOVU61ZSOJYOGa9VyR0nTQxo1qD16pE9SeOuns7rYT+FhuAHUbAaWysH4hEvSRPdwm5NlFoPBCSWfE7lkKQbQyvJXnV7eHKmJGGKrk+4jym52AUryu5YvhkgBk8p6GSrB7+ftFkwpmAJ1G+YsCNxX4Ns7YlLq3CuLdPSVRw1VibzVap9HcI9pDmlzIivfjllbqtwUUhwR2DrwbuAeIwVk3VCdvIi69A6Oi1vUVvwRNTieZ3T2YynDF2X5nECNrxpjH7OGhJ/96mPPARqO10Q== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=raithlin.com; dmarc=pass action=none header.from=raithlin.com; dkim=pass header.d=raithlin.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=raithlin.onmicrosoft.com; s=selector2-raithlin-onmicrosoft-com; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=Udqkvc8NX5f5el6Fsy20PXTJmhDnGWGAWxt7iSrETnw=; b=pJEOcwSFz3wz29TNyt0neINBE69WCqc/afO8Am3G9NtOIXDANaGuyXmbSoUxnJQSYSFi1PUBIeKejNpoiypPBBHqF8x8Pg+1qkzVVwtXBVrcXuH/0tyBr0k3K2Tu9YG6rTmeEtudjf4xjQaMjy8UINjDFcP27n4OXLZqkLcedls= Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=raithlin.com; Received: from TO1PPFC79171DBA.CANPRD01.PROD.OUTLOOK.COM (2603:10b6:b08::68c) by YQXPR01MB5280.CANPRD01.PROD.OUTLOOK.COM (2603:10b6:c01:2e::22) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.8356.21; Sun, 19 Jan 2025 20:00:44 +0000 Received: from TO1PPFC79171DBA.CANPRD01.PROD.OUTLOOK.COM ([fe80::e7b4:a800:3c23:2814]) by TO1PPFC79171DBA.CANPRD01.PROD.OUTLOOK.COM ([fe80::e7b4:a800:3c23:2814%7]) with mapi id 15.20.8356.020; Sun, 19 Jan 2025 20:00:44 +0000 Date: Sun, 19 Jan 2025 13:00:41 -0700 From: Stephen Bates To: Jeff Moyer Cc: linux-btrace@vger.kernel.org, axboe@kernel.dk Subject: Re: [PATCH v1 0/1] Add an option to stop blktrace based on events recorded Message-ID: References: Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: X-ClientProxiedBy: MW4PR04CA0318.namprd04.prod.outlook.com (2603:10b6:303:82::23) To TO1PPFC79171DBA.CANPRD01.PROD.OUTLOOK.COM (2603:10b6:b08::68c) Precedence: bulk X-Mailing-List: linux-btrace@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: TO1PPFC79171DBA:EE_|YQXPR01MB5280:EE_ X-MS-Office365-Filtering-Correlation-Id: b29d90df-1409-4b29-fcfe-08dd38c3f58c X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|366016|10070799003|1800799024|376014; X-Microsoft-Antispam-Message-Info: =?utf-8?B?eW9Sdy9panhhR0xTNDZORE1Fd0dPWC8ra1JIODZZNURnbHdvNVprN21NYnBS?= =?utf-8?B?c3A0WnhEOGhHQmd5WEI2dEFZcy8vMWYyR3ZSNHBCUTlLVXN4VHhDenkyS2JV?= =?utf-8?B?Q2dmR2hpZ25lNkI4V0Z2dGdsZk5sZGJFVEVMTWhvWE16ejJrRm5JSkpvVEh6?= =?utf-8?B?T0Yyc0xBK2MrNjVybnhlYzE0NmFvSXRBU0czc3RrTVcrVENEcUFpemxpMkds?= =?utf-8?B?bURGVm9FeG4wQXdFb0swUFVKenRnUVhQVzVJbTJneVdYZGp6UFlIZ01mK3c4?= =?utf-8?B?V0FOTDNZc0l4THZKMGkzb0l4TVFEQXd6VU5NNHl3ZG5VYzBJcVkrendsR0RY?= =?utf-8?B?ZTI0aXdNV09XUFVvS3JObFhpZlV1STVFYnVEZ1YrbTE4dHRSdlBRckhyR00x?= =?utf-8?B?VzU5UTVrYVBsVkZFaFo1SjBPS01tQTZvemdPNkx3QzJJcU5tMlNGOVFzN3p5?= =?utf-8?B?dFZEYlNKcVlyS2l6S3hvbkRhQU85S3lhMkVOV1JQUktEMjgreUYrYmtiRisx?= =?utf-8?B?M3B1NkMwS1NNR2xhRDlrRzRHcWdueGpYRXRSSDFtT0hVVlorUDgwVXc3dGV6?= =?utf-8?B?UVJNcUZ2K2ZHU25IdksrMHlzL0N4OVc1RjVRM2QxS0taSm40bHpyaDZYNEJT?= =?utf-8?B?a2tjT1M3eHpHVjhBeWt3c0FkaDVWd1ZYSzR0TFFiVXJPdTg0ckdQYU01Zitx?= =?utf-8?B?VmJkc0FGR3NBZGtBN0FDNkxwS3lkUXg4VzA3UldLV0lJSkVxenJyelV0OG9K?= =?utf-8?B?SlVEa09mVVBBZ2NjMkczeE1ZQkRUaVFYUm96ZU1hNEZ4WE5mcHp3aHhRRU1a?= =?utf-8?B?bEtEUmlLakU5ZmdWci9oWmx4eUpQZjFNcHN5OURwelZ5OWxvR2RMaDFLV05S?= =?utf-8?B?OW03Zi9GazV0c1J3WGJjWVdrYTh1RUFIbVdId0t1bnUza3MyR0MxUkdoYlRj?= =?utf-8?B?YkFSRnZQOUhPUTFTUks4RzNqMmp3RjRUSWFraHJycTlTcWZFUzIwRUw4SWZq?= =?utf-8?B?Y2lIREs5dTYxWXdEaWd1Wm1wTlVPL05IMS9UbWx6dS9TaGlQaWpMbmFVVWc5?= =?utf-8?B?dEZKR3pGd1BoNkY0YVpYM3UvTWZuUTM4citEaDJCb0gwUmhSQ2JRaXl1ZzNi?= =?utf-8?B?RnFWbWpKVExQR3BTRTdTcHVuRjBDK0F0T29SY0tnaVgvdUdQTmczaGFMS1Bs?= =?utf-8?B?QnRqSjBlTXkrS0RkdHRnZTdBc2R2QjhicXZsbXZZeVV6WmpucHJoelZIaG13?= =?utf-8?B?bXJkVVpIWlYvMEZ5OG5NUjE1MHkvTXJlTG1LeUN6dDlzNXJkUjVISWZlb2hM?= =?utf-8?B?RGlIZDVKaHowTkVzRjBRS2g5RzcwNnpOZEE5MzRmRGc5QmlIc1ViTy9JbGFD?= =?utf-8?B?V0E2am1Jd3IrSkpVSG1UZ2l0eno0SmROamNtTkppUGhKTmtjanFrejhjVnhr?= =?utf-8?B?VDJzeG5nUzdEMDFpRk9oMEJEZVZBbUhVemhCcVN3aDE1eWVJN29UcnRSTzJG?= =?utf-8?B?VmxicnBiSnk4ckZoakMyQUlOcUs0RFo3UkJZSi9waDJyMEJ3WGdhYnA4MEtY?= =?utf-8?B?blo0K1Y3VU5xWDhCNVNROU9UQjJkenM2QjBuR2ZSQTRlbXd2aG5reUdOVkFO?= =?utf-8?B?L3IzTEdoSnNBNzdidENGazZHTFdmak44UFl6Y0NCWHNFb3E3bE5POVpJclVZ?= =?utf-8?B?b0ljSmhCV0VjWkJ3d0gvYjlLZzJnWjVuRmJFcStMM1NwT1VSR3pyUFVzNVgw?= =?utf-8?B?N2dnRnlKSzZoTDRQK2NscC9wMkFlRzNZT3p1eFlKMG9INTZYZEhJUmI5ZzBP?= =?utf-8?B?NFFxcmJrQUpFU1E5Tkg4TWdieVlyb1gzaGFBc0QxUm9BNzI0Vmd4ZGVTTmp5?= =?utf-8?Q?UvtUgtwypA70d?= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:TO1PPFC79171DBA.CANPRD01.PROD.OUTLOOK.COM;PTR:;CAT:NONE;SFS:(13230040)(366016)(10070799003)(1800799024)(376014);DIR:OUT;SFP:1102; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?RG9WbTZFZjY4N1l3dExqWjM1QStQcE81WHIvU1Bzc0NjOWR5MklhTFRUV3ll?= =?utf-8?B?cTc3LzRJVXlrQkpnNzBxaGUzTkMwRGJIQmd6aERFMG82d0oxRy9heU1melVU?= =?utf-8?B?aHRieENaY0MvWkZXQ1dNTklFRXExbGg1QkNtVFplL2tQTUFOeU1tVjNmQStI?= =?utf-8?B?akp6TDdjcS9yQmRDdE1hbkc5a0ZWdGVPSzlKd3JFa0hJYzFOUTV3dkJvK0Fi?= =?utf-8?B?Y1Q5clRuR3JqZzJNWm43Q21pNjBWa01FMmEzQXl4N0N5V045RExqYnIrekF2?= =?utf-8?B?UW8xcmovYWpxTkZ3V3orRGZ5dkwrbk9xaHlwdkYzZWJQcXBKV01GNUhQbVdT?= =?utf-8?B?ejR2VkdNOGZkS21TQno2RW1nOEptdFNSUVNFM01BS25obmNNSVVuazFpWFY3?= =?utf-8?B?MFczK2hUZEVvQ0tqNkdDMUYxTlJFcUZ3bmFjb2kwbWt0VFd5NUZQeE14VVB3?= =?utf-8?B?bGlZVUlxaXZ3RFcrZmMzRkZKR1FpRmp4V1ZZM1hLcjZFSCtHQXBWa1dEUWtW?= =?utf-8?B?S1M2OEJJck9uZTYzSTFIbkM0Vlp5L0ViVzV1L1E3Y2dzcmJ5TjVyUU4rK3hN?= =?utf-8?B?dDBVenZFWGhyc0xObGY5N2NkUmlwR0k0Mzl2YzFYRVdVcmNoRjhuT1diZnRZ?= =?utf-8?B?RHEvc0I1SFRqbTd4UlA5dGE1UWFHNUVuUkV4TEhqTVo5K2JFY0IrNjNDOUZV?= =?utf-8?B?ckZTbXZSRWxtRzJucGUzek1TNUc1ZjZkRi81Umk0cW9VZTR2cFhJN0pRUmdE?= =?utf-8?B?MXdmQnV2clNiUmhjMWxDVWpZKzJucVY3blA1UlBNN0dXNFlaWnZnUUNvdmhB?= =?utf-8?B?UGNpU3FJZ3hOMzBGOWJaNVFiZWx2eXVGa2gvblp4dUpUOVRtcGlhdGxWUytM?= =?utf-8?B?emFYWjh3Q1o2SEdrV1BFRHQ4bVd3ZDNueUZ3RFgyWmpycHRGV1dQWjFTTEhw?= =?utf-8?B?aEZvZ283TEJGSkp6UThvZEFNT1N3Y2NWcGxrZzcvMUtJVkJSNXhPMlRoK1k2?= =?utf-8?B?dnE3U0JEWVFwNEk3L05yVFEzNEl6OWQvL1lDTnZjWFAvTmpwMk0wS21ZRHJG?= =?utf-8?B?STFsNFdYdlh0T3ArTUtoeXVUZXNpbVVYU2grVEMveDNxYnhDODd3MmpKSHR3?= =?utf-8?B?TDc4RnU0eVRkaEczc0VYT28rdG10ZUpxbDZVN0Fxbzg4dUlxcnd3aVlDUjhi?= =?utf-8?B?L0N4clBUOHN0ek8xNkFQK3Q5L0lKeDg1dFlLUkIvaUExVzRRdHQybXdMWWwz?= =?utf-8?B?K2JlUzl1dnFJcDlGYWdKZ2FoK1d2ai9pUU52WDFHQ1VmbS9BUDJBWXBnUSs2?= =?utf-8?B?RGUrY2FjWjBDcUVUa2NaK0Nqc3luOS9jVVhvMGY2Yk9VNmRxdVV5TUpLaUto?= =?utf-8?B?VkUrUUplT01IZzArMTc1bE1zY2VnYkg3VG5WSkxxZy9jemZKOFp1ZDFBOTZu?= =?utf-8?B?eXlTaC9vcG9Mb1kzZFp2czY3eTQvcGt2YkRYWEpXQVR1RHE4dktFSUR3c3V1?= =?utf-8?B?YWpoaHYzN0RpUnF1Y3g1czdJaHFQdWs1VWY0THRjcGxqZFhYNkY5NUxPbktF?= =?utf-8?B?ME93TW9xK2g1Q0lNa3Z0NEsyVi8xOVdHSXp6N2VCcVRUTHRFeEY4T2doVG1W?= =?utf-8?B?dGs1SXY5bDNHT3hESW1sY3ZHK2srMUVKd0lZVnNoZUtMbG0xSnJIZU0wU2tm?= =?utf-8?B?VElzd04ySWUvYmkxVFp5Z2xHY2NrV2cwZVBVeTVIc0JvM1I5bUkwcm5LREpC?= =?utf-8?B?QXlEYU1KanFhTmI5RzZGaEFFRVBZeTVveThmamlGNnZVTmxxdDhMSVUwZkJK?= =?utf-8?B?VExQNHRjK0xtTFNWclZmRkQ2Y0gxNUR2K2hVdVdsWWg3TXA2cFlBMXI2bFpp?= =?utf-8?B?bXFuZndpYzZFN3FRTnlhaDVzd1FiYk1aakVnbC9OLzRtWmhBbzhFQTdpa3hy?= =?utf-8?B?YWVkeHlnK3Nsakw3WTRSUlBtdnRQTE8rSmFGcVZkc3dQcU00dk5GT2tPZU54?= =?utf-8?B?LzBXV1VlclpXNEI4OHB1bjViaURtZ0UvdFQ4YzdNdkY1Q201NmR5TkFadkxu?= =?utf-8?B?dEZFYm9VSENDNS9VbmtWeHlHcjhyMXdaQXlEK1RtWkdMVlgyMk5ZTFE3Mjdm?= =?utf-8?B?bnp1STl1Y1pwam82ZEZ5Wmw2S1QvZzE4djFEQnkrYkpVY2kvMUM3NXFERG1q?= =?utf-8?Q?NJv6omuIpo7n5eXKu4GmfHQ=3D?= X-OriginatorOrg: raithlin.com X-MS-Exchange-CrossTenant-Network-Message-Id: b29d90df-1409-4b29-fcfe-08dd38c3f58c X-MS-Exchange-CrossTenant-AuthSource: TO1PPFC79171DBA.CANPRD01.PROD.OUTLOOK.COM X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 19 Jan 2025 20:00:44.6740 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 18519031-7ff4-4cbb-bbcb-c3252d330f4b X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: DhNbzotfYaIzUMMEcvbhNYRiY/YzsCBvwbmoXde6bcflMFiQHvaL+7T1zqcvbrIilCOq9RwglRPJw7eQRy6djw== X-MS-Exchange-Transport-CrossTenantHeadersStamped: YQXPR01MB5280 Hi Jeff > Can you expand on the use case? Why is the number of events a useful > parameter? > > Thanks, > Jeff I am working on tying blktrace into a prometheus exporter so I can monitor block-level activity across a fleet of storage servers. I don't want to overload either the storage server CPUs or the exporter itself when the server is under high load so I want to avoid using the time-based argument for blktrace. If I have access to an events based option I can run this knowing that in high-load situations I will not be capturing many, many IO and perhaps slowing down the server in the process. Does that make sense? Cheers Stephen The 01/14/2025 09:29, Jeff Moyer wrote: > Hi, Stephen, > > Stephen Bates writes: > > > Hi > > > > I am exploring the idea of tying blktrace to a prometheus exporter to > > gather more precise block layer activity across a fleet of servers. As > > part of that I thought it might be useful to be able to run blktrace > > until a user-specified number of events are recorded. > > > > So the following patch adds a new option to do that. I also updated > > the relevant documentation. > > > > I'd appreciate feedback or comments on this! > > Can you expand on the use case? Why is the number of events a useful > parameter? > > Thanks, > Jeff > -- Cheers Stephen Bates, PhD.