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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 71327CA101F for ; Wed, 10 Sep 2025 16:44:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:MIME-Version:References:In-Reply-To:Message-ID:Subject:Cc:To: From:Date:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=5BIaMk8aVE9jGIkF25DrmIUwxCYdXauE6pkpJVHHMAU=; b=U+anPniCw/aweDxgXbfq/s3ayJ Vh/Pg7Y+ZL9B3SYbTP4DbSuTqfAbkv1F3TPvrD3plzj85y8MYYAhCTMuRqmwHRsqNqJUHkcz/vNER 2zGCqLaH+qghCxh6cbpAB6cXIPvrKZC8S4dL4lYjubuD3CjPgANVJPLslMOAbctPLG0DpRDdIw4lT WiQiuTEKXevpuvcvFGJUo5tY3KKJNhwtyixK09o3HKHT4YNpynZHvHLCZHnMUEOSChAlllFMxxSff DnX4yp0XKeaSAyOubgxP3s5ELK5zxDrG4xmo6Ymc4DuXbKwQeLnkbx9mEdNCJ9hQZAE5IKyp050iZ 8Ma7u5Qg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1uwNvp-0000000FZfN-12zU; Wed, 10 Sep 2025 16:44:29 +0000 Received: from smtprelay0013.hostedemail.com ([216.40.44.13] helo=relay.hostedemail.com) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1uwNvm-0000000FZcT-1MMe for linux-arm-kernel@lists.infradead.org; Wed, 10 Sep 2025 16:44:27 +0000 Received: from omf19.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id 86C39117880; Wed, 10 Sep 2025 16:44:22 +0000 (UTC) Received: from [HIDDEN] (Authenticated sender: rostedt@goodmis.org) by omf19.hostedemail.com (Postfix) with ESMTPA id 2C88D20025; Wed, 10 Sep 2025 16:44:19 +0000 (UTC) Date: Wed, 10 Sep 2025 12:45:09 -0400 From: Steven Rostedt To: Vincent Donnefort Cc: mhiramat@kernel.org, mathieu.desnoyers@efficios.com, linux-trace-kernel@vger.kernel.org, maz@kernel.org, oliver.upton@linux.dev, joey.gouly@arm.com, suzuki.poulose@arm.com, yuzenghui@huawei.com, kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, jstultz@google.com, qperret@google.com, will@kernel.org, aneesh.kumar@kernel.org, kernel-team@android.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH v6 04/24] tracing: Add reset to trace remotes Message-ID: <20250910124509.14e2c69f@gandalf.local.home> In-Reply-To: References: <20250821081412.1008261-1-vdonnefort@google.com> <20250821081412.1008261-5-vdonnefort@google.com> <20250908193757.079aae76@gandalf.local.home> <20250909094028.3265b751@gandalf.local.home> <20250909143948.420bfb1c@gandalf.local.home> <20250909145236.69192cd0@gandalf.local.home> X-Mailer: Claws Mail 3.20.0git84 (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-Stat-Signature: 134qpie7ddpmaaj1uqq33s96zuakqbyg X-Rspamd-Server: rspamout05 X-Rspamd-Queue-Id: 2C88D20025 X-Session-Marker: 726F737465647440676F6F646D69732E6F7267 X-Session-ID: U2FsdGVkX198PcTMaukh33mwqIRhwDqNrdifUI66crI= X-HE-Tag: 1757522659-640068 X-HE-Meta: U2FsdGVkX1+3HNOYDX1kRWm9XkAAF+NlcLIGDkVLNzH1iYc4AWJqpIE4VZh98lQ3n2BNfksoq8Ym95szXl+L/hfduWR7OZyh3GRJVva8FlS31lxD3CEgOEKS1r6yQYmDyZyenpn373H68mcmS/pwNT8pKaTsscTTW7IR40+AtInmBfP6fnOPDWhUJAnLgb55qs0+7T5ogk8bErBQMhjry4WIAd3WvaYerSAPYDm+kTYY0ok77pNa6gB4Nv8k1FnfxgDnnp8nzeKLCJl2mQ/V+GpU4LvSEHFKNvbdusHhezxS9U4DDjZopePAJouWK3I5wLt31uqWfwnwa/7vF2bQcicCLYR/QwW+ X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250910_094426_425558_64C891E6 X-CRM114-Status: GOOD ( 13.51 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Wed, 10 Sep 2025 10:45:05 +0100 Vincent Donnefort wrote: > > If we are gonna keep the "trace" file, let's make sure it's fully > > implemented. > > I was more worry about the ring-buffer page order that can be reshuffled on each > swap_reader_page(), making the page links useless in the kernel. Ideally, the > meta-page would keep the page ID order somewhere. Yeah, internally we could keep the order of the pages. Shouldn't be too hard, as the swapping happens by the kernel. > > Alternatively, we could walk all the buffer pages to read the timestamp and > re-create the order but that sounds quite cumbersome. No, having a separate array of the order is probably what we want. Then every swap_reader_page() will update the array. The trace iterator could simply walk that array. -- Steve