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 [216.205.24.124]) by sourceware.org (Postfix) with ESMTP id D3E503857435 for ; Mon, 13 Sep 2021 14:40:15 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org D3E503857435 Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-505-fFsMa9DDOU28mdGMGrvxOA-1; Mon, 13 Sep 2021 10:40:14 -0400 X-MC-Unique: fFsMa9DDOU28mdGMGrvxOA-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 220D6101F7A1; Mon, 13 Sep 2021 14:40:13 +0000 (UTC) Received: from oldenburg.str.redhat.com (unknown [10.39.195.4]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 59AB36D983; Mon, 13 Sep 2021 14:40:11 +0000 (UTC) From: Florian Weimer To: "H.J. Lu" Cc: libc-alpha@sourceware.org, gdb@sourceware.org, libc-coord@lists.openwall.com, Daniel Walker Subject: Re: [PATCH v9 1/1] Extend struct r_debug to support multiple namespaces [BZ #15971] References: <20210910201219.156682-1-hjl.tools@gmail.com> <20210910201219.156682-2-hjl.tools@gmail.com> Date: Mon, 13 Sep 2021 16:40:09 +0200 In-Reply-To: <20210910201219.156682-2-hjl.tools@gmail.com> (H. J. Lu's message of "Fri, 10 Sep 2021 13:12:19 -0700") Message-ID: <87sfy8bkty.fsf@oldenburg.str.redhat.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.2 (gnu/linux) MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain X-Spam-Status: No, score=-6.7 required=5.0 tests=BAYES_00, DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, RCVD_IN_DNSWL_LOW, RCVD_IN_MSPIKE_H2, SPF_HELO_NONE, SPF_NONE, TXREP autolearn=ham autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on server2.sourceware.org X-BeenThere: gdb@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gdb mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 13 Sep 2021 14:40:17 -0000 * H. J. Lu: > + /* Add the new namespace to the linked list. After a namespace > + is initialized, r_brk becomes non-zero. A namespace becomes > + empty (r_map == NULL) when it is unused. But it is never > + removed from the linked list. */ > + r->r_next = _r_debug_extended.r_next; > + atomic_store_release (&_r_debug_extended.r_next, r); I think the addition should be at the end of the list, and the list update (with release MO) should come last. That should help with reading the list concurrently. Rest looks okay to me. Thanks, Florian