From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1DD6EC4332F for ; Wed, 13 Dec 2023 00:44:09 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 61C9C6B041E; Tue, 12 Dec 2023 19:44:08 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 5CBF16B041F; Tue, 12 Dec 2023 19:44:08 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 46DBE6B0420; Tue, 12 Dec 2023 19:44:08 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id 36BD16B041E for ; Tue, 12 Dec 2023 19:44:08 -0500 (EST) Received: from smtpin01.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay02.hostedemail.com (Postfix) with ESMTP id F2762120AA4 for ; Wed, 13 Dec 2023 00:44:07 +0000 (UTC) X-FDA: 81559948134.01.890123D Received: from sin.source.kernel.org (sin.source.kernel.org [145.40.73.55]) by imf19.hostedemail.com (Postfix) with ESMTP id E92181A0013 for ; Wed, 13 Dec 2023 00:44:05 +0000 (UTC) Authentication-Results: imf19.hostedemail.com; dkim=none; dmarc=none; spf=pass (imf19.hostedemail.com: domain of "SRS0=4TYM=HY=goodmis.org=rostedt@kernel.org" designates 145.40.73.55 as permitted sender) smtp.mailfrom="SRS0=4TYM=HY=goodmis.org=rostedt@kernel.org" ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1702428246; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=RD4JcZy4ThXtSoEV9jj94QNXJN2qP/DaMuwlZb6MEnE=; b=8HQYJejxhOOXCtFfYMW+HHU74RYhvI56hL5dFqJ8YptMOwCTxxCu/DQkjS+DzaUzPc4xgY n3YLIsn2ZsCf/zm8pF8E67uXncAFaJY/P0QqOPZhtL47pABIfh4VyfSmTTSoJqcIFU4Xtk oE36mhKdIeq+xwwTSGU4xTpsTjfdE00= ARC-Authentication-Results: i=1; imf19.hostedemail.com; dkim=none; dmarc=none; spf=pass (imf19.hostedemail.com: domain of "SRS0=4TYM=HY=goodmis.org=rostedt@kernel.org" designates 145.40.73.55 as permitted sender) smtp.mailfrom="SRS0=4TYM=HY=goodmis.org=rostedt@kernel.org" ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1702428246; a=rsa-sha256; cv=none; b=hg0t7g9tIbg2jxbUWJZsiCK7lrwLlt9qN2hwOnAM/L62C9nM8lUdYaqu+CZUwphmEyucXf DKA3ubVgNpYw1hygiN2tg69PfNGZh4GCyxhOWwBhlXxozrwUs0OJxHYTDsK9Oi3OkgdG0E eKzD7Qh1GA/g+f2Ph6G3+s8I9pi+T+8= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sin.source.kernel.org (Postfix) with ESMTP id 93A08CE1C64; Wed, 13 Dec 2023 00:44:02 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 04D94C433C8; Wed, 13 Dec 2023 00:43:58 +0000 (UTC) Date: Tue, 12 Dec 2023 19:44:41 -0500 From: Steven Rostedt To: Alexander Graf Cc: , , , , , , , , Eric Biederman , "H. Peter Anvin" , Andy Lutomirski , Peter Zijlstra , Rob Herring , Andrew Morton , Mark Rutland , Tom Lendacky , Ashish Kalra , James Gowans , "Stanislav Kinsburskii" , , , , Anthony Yznaga , Usama Arif , "David Woodhouse" , Benjamin Herrenschmidt Subject: Re: [PATCH 08/15] tracing: Introduce names for ring buffers Message-ID: <20231212194441.2701c48b@gandalf.local.home> In-Reply-To: References: <20231213000452.88295-1-graf@amazon.com> <20231213000452.88295-9-graf@amazon.com> <20231212191546.603c0703@gandalf.local.home> X-Mailer: Claws Mail 3.19.1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam09 X-Rspamd-Queue-Id: E92181A0013 X-Stat-Signature: e6omucmact8w3bysibhr8jojpw3ne6kd X-Rspam-User: X-HE-Tag: 1702428245-848858 X-HE-Meta: U2FsdGVkX18gFfk1wQ0GNtozbXkC7KeqKyeY3y60AABfILAT9Bpws+6LpYCa4ke5iY84V8J1RjJOoPAn39qu54VwwaOwDjAtLUysTLwqFwusCyGl+rprsjKB5vZDlnBahI6IJ+NAdeV9nEm91YXK+gUWVWbjQ3tbZUsVD6tFTEuXLHnmos+Rrq8eiVaHertCPZzfWvcG6n20r1p0rYoh/YwR90I/c0zYdpHBQWBny/o7643ST+PrKyso3URvg04CXWxEmHhWmjGRi8Xoxw68+jM8q7lepgawtd255hzd4Sn53alG7bEqHhR1qjDWeVGhIieM0lEvMfoPrG/NBQ01UKvLZzSbOEF5fHAYcW7YMYb94HOAgzuMMm5ytpeuammybp9T5KWBdeVYVI3WLfC2HBzFnrYkQ+pUNMFLUYS6DenTuOutn3ma9TKn6L5c1EiOlC63Ac/ZSYylKGrikvtKAQwEaghBrSkXIeyVIuNdQHRfMKIrcIaV1mXHgFDLtmPDEeteZr/9TjOBpMFt3jG0j0PPpb39pNgaZiF8xJsqxgY37qI2SFkugl30w0MbSG5E3itOqmzcZO0Py96H2ZCzk/9O0p3Knz+bOq1KC8dTGqcWSlsJCzFhAIjvKG8LpR0D7Yhwgb6K61NtmC2EaMo8v+wg0WTEKhi5FaSLlwTh8D+8OOyWatHWkX5oa5BIDhJvSVhNJMGY1tFF9dVpEq1BmvPAuBzdIgiVFAC4Ien6+DpHzRtSY1qb3Hgpd89AYmr83R9fSyqmHamVVRxUKFFfSXXKMuxmfnvJVCJ3qA3lQwSsM/LWRU91DVUBNRYyRPNdr+K/uz6+zn7t8VWf+WUPpL/HuRk/x6chxMn8GPvc/KPfvdOMbt8DUXfNlXdo/VQq0bBl0CpE3oLMWmA/OGcUwrVT6lm+bTU2KDNbO8r1FjBhFS0YNIMUGdzKJE6SfX0H7bf0ihg5PVIrG4U4D1h 4yEC64VJ VKksadIgklBlYxU8+5jL5MJy5wuG8bsQdVY8Hedh9ooW80GHWAIZjTWkmvuyFMQrCGFbESq8OTUnaMjCj0JuPAlamsIHQcy4Cm7ju1+ket7uqPF7rz5bstyWnL1sO0abdUVdQc0hzpHkj4idaQfhZFQ86A+gGcuB7O/S3r8P9GQMGVOMBoGh/MpfXjWORtXsqFaL7TUhyHT3qUO1Ki8M3SVfhio1Ab6/5Q6k1fTyCvx/x1uJBsCebGXn0jW+TNnjI/WTMON8JoTeqDCt0nX4YGh2WvxGSq7NToeQwpd+YyymwJi1rOu8w+nAipHKlDCSOrweUNcXRC8gqoF93J0mwg9JJ3z+PeNwKZqOp X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Wed, 13 Dec 2023 01:35:16 +0100 Alexander Graf wrote: > > The trace_array is the structure that represents each tracing instance. And > > it already has a name field. And if you can get the associated ring buffer > > from that too. > > > > struct trace_array *tr; > > > > tr->array_buffer.buffer > > > > tr->name > > > > When you do: mkdir /sys/kernel/tracing/instance/foo > > > > You create a new trace_array instance where tr->name = "foo" and allocates > > the buffer for it as well. > > The name in the ring buffer is pretty much just a copy of the trace > array name. I use it to reconstruct which buffer we're actually > referring to inside __ring_buffer_alloc(). No, I rather not tie the ring buffer to the trace_array. > > I'm all ears for alternative suggestions. I suppose we could pass tr as > argument to ring_buffer_alloc() instead of the name? I'll have to spend some time (that I don't currently have :-( ) on looking at this more. I really don't like the copying of the name into the ring buffer allocation, as it may be an unneeded burden to maintain, not to mention the duplicate field. -- Steve