From patchwork Wed Oct 19 15:16:50 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kurz X-Patchwork-Id: 13011992 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 92653C43219 for ; Wed, 19 Oct 2022 15:21:37 +0000 (UTC) Received: from localhost ([::1]:52136 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1olAsy-00068p-Dx for qemu-devel@archiver.kernel.org; Wed, 19 Oct 2022 11:21:36 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:33416) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1olAob-00043d-1i for qemu-devel@nongnu.org; Wed, 19 Oct 2022 11:17:05 -0400 Received: from us-smtp-delivery-44.mimecast.com ([207.211.30.44]:35654) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1olAoY-00022C-Sf for qemu-devel@nongnu.org; Wed, 19 Oct 2022 11:17:04 -0400 Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-41-IxPVhthtOTucQyILKEnXCQ-1; Wed, 19 Oct 2022 11:16:55 -0400 X-MC-Unique: IxPVhthtOTucQyILKEnXCQ-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 246F63C0219A; Wed, 19 Oct 2022 15:16:55 +0000 (UTC) Received: from bahia.redhat.com (unknown [10.39.192.144]) by smtp.corp.redhat.com (Postfix) with ESMTP id 215349459C; Wed, 19 Oct 2022 15:16:54 +0000 (UTC) From: Greg Kurz To: qemu-devel@nongnu.org Cc: =?utf-8?q?Alex_Benn=C3=A9e?= , =?utf-8?q?Daniel_?= =?utf-8?q?P_=2E_Berrang=C3=A9?= , Richard Henderson , Paolo Bonzini , Greg Kurz Subject: [PATCH v2 1/2] util/log: Derive thread id from getpid() on hosts w/o gettid() syscall Date: Wed, 19 Oct 2022 17:16:50 +0200 Message-Id: <20221019151651.334334-2-groug@kaod.org> In-Reply-To: <20221019151651.334334-1-groug@kaod.org> References: <20221019151651.334334-1-groug@kaod.org> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.5 Received-SPF: softfail client-ip=207.211.30.44; envelope-from=groug@kaod.org; helo=us-smtp-delivery-44.mimecast.com X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_LOW=-0.7, SPF_HELO_NONE=0.001, SPF_SOFTFAIL=0.665 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: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" A subsequent patch needs to be able to differentiate the main QEMU thread from other threads. An obvious way to do so is to compare log_thread_id() and getpid(), based on the fact that they are equal for the main thread on systems that have the gettid() syscall (e.g. linux). Adapt the fallback code for systems without gettid() to provide the same assumption. Suggested-by: Paolo Bonzini Signed-off-by: Greg Kurz --- util/log.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/util/log.c b/util/log.c index d6eb0378c3a3..e1c2535cfcd2 100644 --- a/util/log.c +++ b/util/log.c @@ -72,8 +72,13 @@ static int log_thread_id(void) #elif defined(SYS_gettid) return syscall(SYS_gettid); #else + static __thread int my_id = -1; static int counter; - return qatomic_fetch_inc(&counter); + + if (my_id == -1) { + my_id = getpid() + qatomic_fetch_inc(&counter); + } + return my_id; #endif }