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 lists.gnu.org (lists.gnu.org [209.51.188.17]) (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 AF1A7C87FD1 for ; Tue, 5 Aug 2025 16:44:16 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ujKl9-0001kc-1I; Tue, 05 Aug 2025 12:43:31 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ujKkz-0001i5-BQ for qemu-devel@nongnu.org; Tue, 05 Aug 2025 12:43:22 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ujKkw-0000M1-CW for qemu-devel@nongnu.org; Tue, 05 Aug 2025 12:43:20 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1754412196; h=from:from:reply-to: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=i7JJzhseou2jwbKcnse4HM7n6Knnag3S9DORmIsA2yk=; b=YoXMVwNt3TCQO62aXXNhDWHzkdxbbTVAG/awTI2QLtPhURjDLGwUP5nwDCEBdJ7IQ/mvLp MK+HoGS5dUoUuT+CS6T3HeqWJIFaLac7x94ut4fivFxmGTe8q7HoTgHy54UcJnyYpbe+Y6 ONH9jV8MXxalk7iI3HQIRKXEuCeby84= Received: from mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-190-ppWLBKDFPdeea9mEvW7szQ-1; Tue, 05 Aug 2025 12:43:13 -0400 X-MC-Unique: ppWLBKDFPdeea9mEvW7szQ-1 X-Mimecast-MFC-AGG-ID: ppWLBKDFPdeea9mEvW7szQ_1754412192 Received: from mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.4]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 25A08195606D; Tue, 5 Aug 2025 16:43:12 +0000 (UTC) Received: from redhat.com (unknown [10.42.28.80]) by mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 12E4C3000199; Tue, 5 Aug 2025 16:43:09 +0000 (UTC) Date: Tue, 5 Aug 2025 17:43:06 +0100 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Manos Pitsidianakis Cc: qemu-devel@nongnu.org, qemu-rust@nongnu.org, Philippe =?utf-8?Q?Mathieu-Daud=C3=A9?= , alex.bennee@linaro.org Subject: Re: [PATCH RFC 0/5] rust: implement tracing Message-ID: References: <20250804-rust_trace-v1-0-b20cc16b0c51@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/2.2.14 (2025-02-20) X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.4 Received-SPF: pass client-ip=170.10.133.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: 12 X-Spam_score: 1.2 X-Spam_bar: + X-Spam_report: (1.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H5=0.001, RCVD_IN_MSPIKE_WL=0.001, RCVD_IN_SBL_CSS=3.335, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=0.001, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Tue, Aug 05, 2025 at 07:25:39PM +0300, Manos Pitsidianakis wrote: > On Tue, Aug 5, 2025 at 7:05 PM Daniel P. Berrangé wrote: > > > > On Mon, Aug 04, 2025 at 04:47:13PM +0300, Manos Pitsidianakis wrote: > > > This RFC series contains some simple patches I've been sitting on for > > > some months to allow tracing in rust devices in a similar matter to C, > > > only it's done via a proc-macro codegen instead of using tracetool > > > script or equivalent. > > > > IIUC, this series is only emitting the traces events via the > > qemu_log function, and so feels like it is missing the benefit > > of tracing, vs the traditional logging framework. > > > > In our RHEL & Fedora distro builds we disable the log backend > > and enable dtrace, so that we have fully dynamic tracing and > > observability across the kernel, qemu, libvirt and other > > components with dtrace integration. > > Hi Daniel, > > Thanks for the insight! Do you have any points where I should look at > the trace implementation for how the different backends are supported? > > So I think there's already work in progress to support proper tracing > for Rust, I only sent this as a temporary fixup to provide some kind > of parity between C and Rust implementations until a proper, better > solution is available that can replace it. Can the rust code not easily consume the existing functions in the trace.h files generated for the C code as a short-term solution ? It would not benefit from the code inlining in the same way as C would, but it would at least give feature parity for tracing with all the trace backends are available. Then, we can look at optimizing with a pure rust impl of some backends at a later date, to regain what we lost from lack of inlining ? With regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|