From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by sourceware.org (Postfix) with ESMTPS id A5F413858417 for ; Wed, 13 Dec 2023 14:18:24 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org A5F413858417 Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=redhat.com ARC-Filter: OpenARC Filter v1.0.0 sourceware.org A5F413858417 Authentication-Results: server2.sourceware.org; arc=none smtp.remote-ip=170.10.129.124 ARC-Seal: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1702477105; cv=none; b=ESN5mLjOGiw7ZwtWLpVfRpUTs8Lp0K9VUp5tCqJKwBUXFnswbRhXjBGdoMJ9pQNTkpnvxn7cMO05lEZcuAaCuybH8RMWY/QYdtQF7wPLtDGBH5mvnJvvKSeFmTZxVBL3TBJM19VxIEEmj0+LpLu2HwwDn0phkrMjhoxkxm4kgm4= ARC-Message-Signature: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1702477105; c=relaxed/simple; bh=zPp1HFhXsxZQ0Y9RLRWUUs/5JK5xxtgW1k6dd8NrwxI=; h=DKIM-Signature:From:To:Subject:Date:Message-ID:MIME-Version; b=lfHXeVFd+9TGE1x9SmtcXrWJhfrDeEmSk3tIkg4XdoK7dHUOE4BvUu+D7OWo15pWpW99Z1N7zeNs8wXSFqaLYd6cvCdVNm4maOEdUNox4CT2XxVLgWVa/yNyvIl6oeaLdK1A7v6Sk7kJFhd6bARXP+TF2QYwLDIAvLvw6I2AgCg= ARC-Authentication-Results: i=1; server2.sourceware.org DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1702477104; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type; bh=rKTKETYWKy3sw+xMGJXyRwW8Gle/YWdWweyLjVWcJlA=; b=HpqSuiQURRU2Cc7m84JsQXFI0BDO4qxtCvPoJJcZ+t8sqy34GivmGKYyiy/ffcOXrSccEz xyLELM9o1ujQB0NJy+XCJWPu+nIElMZ8T8hIYcXhkdp9eAWYLhODY1qbj44k+xsRa3BqkW 8TXMVHjTqO/XGCBeiKekvxOdtNt4cfs= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-443-D8qKIHrTMJaw1aYJaqT8cA-1; Wed, 13 Dec 2023 09:17:55 -0500 X-MC-Unique: D8qKIHrTMJaw1aYJaqT8cA-1 Received: from smtp.corp.redhat.com (int-mx10.intmail.prod.int.rdu2.redhat.com [10.11.54.10]) (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 mimecast-mx02.redhat.com (Postfix) with ESMTPS id B3C0E101AA4D for ; Wed, 13 Dec 2023 14:17:54 +0000 (UTC) Received: from oldenburg.str.redhat.com (unknown [10.39.192.122]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 304DB492BF0 for ; Wed, 13 Dec 2023 14:17:54 +0000 (UTC) From: Florian Weimer To: gcc@gcc.gnu.org Subject: Switching x86_64-linux-gnu to GNU2 TLS descriptors by default Date: Wed, 13 Dec 2023 15:17:52 +0100 Message-ID: <871qbqp4of.fsf@oldenburg.str.redhat.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/28.3 (gnu/linux) MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.10 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain X-Spam-Status: No, score=-4.6 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_NONE,RCVD_IN_MSPIKE_H4,RCVD_IN_MSPIKE_WL,SPF_HELO_NONE,SPF_NONE,TXREP,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: I feel like I have asked this before. Currently, GCC uses calls to __tls_get_addr to obtain the address of global-dynamic TLS variables. On other architectures with support for GNU2 TLS descriptors, those are used by default. Should we flip the default to GNU2 descriptors? Support has been available in glibc for a long, long time. Is there any other reason for not doing this? On the glibc side, the behavior regarding lazy initialization and symbol binding does not change whether the old or new interface is used. Thanks, Florian