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a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1758276630; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=76QIhizl3X0PSKL6TH0leSos0Xva+X0+TyePkTiegJs=; b=M0JwuvNvli0UU++GYjUSHDVufvKtzFvOdwUcyCu30xpyWDeqyp6bWhrUVCQzQCUQZG95pp 7LPvmRmyVhsxU7ObNmGCRjJPD4d2bEDeLeGve8FeRYOfsUfy0v70f/1tnf4a2tKofJ5FEu NAnU61GHbRDVIfLunR7EdDGletztM0M= X-MC-Unique: yvO4MEY4OA-xBVoPePiPGw-1 X-Mimecast-MFC-AGG-ID: yvO4MEY4OA-xBVoPePiPGw_1758276626 From: Paolo Bonzini To: qemu-devel@nongnu.org Cc: mads@ynddal.dk, stefanha@redhat.com Subject: [PATCH] tracing: deprecate "ust" tracing backend Date: Fri, 19 Sep 2025 12:10:21 +0200 Message-ID: <20250919101021.119590-1-pbonzini@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.93 Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=170.10.129.124; envelope-from=pbonzini@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.005, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, RCVD_IN_VALIDITY_CERTIFIED_BLOCKED=0.001, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=ham 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: , Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: qemu-devel-bounces+importer=patchew.org@nongnu.org X-ZohoMail-DKIM: pass (identity @redhat.com) X-ZM-MESSAGEID: 1758276777234116600 Content-Type: text/plain; charset="utf-8" The "ust" backend is complex (tracetool contains two output formats just for that backend). It is not clear if if it has any users, and LTTng anyway can use the uprobe tracepoints provided by the "dtrace" backend, therefore deprecate "ust". Signed-off-by: Paolo Bonzini --- docs/about/deprecated.rst | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/docs/about/deprecated.rst b/docs/about/deprecated.rst index aa300bbd507..57250f9d47f 100644 --- a/docs/about/deprecated.rst +++ b/docs/about/deprecated.rst @@ -533,3 +533,12 @@ command documentation for details on the ``fdset`` usa= ge. =20 The ``zero-blocks`` capability was part of the block migration which doesn't exist anymore since it was removed in QEMU v9.1. + +Host features +------------- + +``ust`` tracing backend +----------------------- + +LTTng can use uprobe tracepoints, therefore it is recommended to use +the ``dtrace`` backend instead. --=20 2.51.0