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Received: from AM0PR0402MB3395.eurprd04.prod.outlook.com (2603:10a6:208:1a::16) by PAXPR04MB8672.eurprd04.prod.outlook.com (2603:10a6:102:21f::18) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.7046.21; Tue, 28 Nov 2023 15:06:04 +0000 Received: from AM0PR0402MB3395.eurprd04.prod.outlook.com ([fe80::14c8:fc35:a9ae:9c9d]) by AM0PR0402MB3395.eurprd04.prod.outlook.com ([fe80::14c8:fc35:a9ae:9c9d%4]) with mapi id 15.20.7046.015; Tue, 28 Nov 2023 15:06:04 +0000 Message-ID: <1ef6c0a0-4d82-4fdc-8007-87e054a4c08d@suse.com> Date: Tue, 28 Nov 2023 16:06:03 +0100 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 2/2] tracing: Disable events in reverse order of their enable operation Content-Language: en-US To: Steven Rostedt Cc: mhiramat@kernel.org, mathieu.desnoyers@efficios.com, zhengyejian1@huawei.com, linux-trace-kernel@vger.kernel.org, linux-kernel@vger.kernel.org References: <20231127151248.7232-1-petr.pavlu@suse.com> <20231127151248.7232-3-petr.pavlu@suse.com> <20231127125815.4a4d06c6@gandalf.local.home> From: Petr Pavlu In-Reply-To: <20231127125815.4a4d06c6@gandalf.local.home> Content-Type: text/plain; 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It closes a small window >> where an event would be still registered and could be hit, but would >> unnecessarily go directly to a ring buffer. > > There's little benefit to the above. Going to the ring buffer and reverting > it is just a bit more expensive, but should not be an issue with this small > window. > >> * The SOFT_DISABLED flag is now consistently set only when SOFT_MODE is >> also set. > > This code is a bit fragile, and I rather not change the logic. There's a > lot of corner cases. > > I'm not saying that this is a bad change, I just don't want to add it and > find out later it broke one of the corner cases. To add this would require > an analysis that every input produces the same output with and without this > change. > > If you want to make a table showing all inputs between soft_disable and the > flags, and show that the result produces the same updates, I'll then > reconsidered applying this. Ok, that is fair. It looked to me as a reasonable change but I don't feel strongly about it and I understand your concern. I guess I'll drop it in v2. Thanks, Petr