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 X-Spam-Level: X-Spam-Status: No, score=-6.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2B84DC76192 for ; Tue, 16 Jul 2019 14:16:10 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 055F22173E for ; Tue, 16 Jul 2019 14:16:09 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 055F22173E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linaro.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:49500 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hnOFT-0002XD-Qg for qemu-devel@archiver.kernel.org; Tue, 16 Jul 2019 10:16:07 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:38267) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hnOF8-0001Y4-RH for qemu-devel@nongnu.org; Tue, 16 Jul 2019 10:15:48 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hnOF7-00068g-Fw for qemu-devel@nongnu.org; Tue, 16 Jul 2019 10:15:46 -0400 Received: from indium.canonical.com ([91.189.90.7]:35372) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1hnOF7-00068C-8d for qemu-devel@nongnu.org; Tue, 16 Jul 2019 10:15:45 -0400 Received: from loganberry.canonical.com ([91.189.90.37]) by indium.canonical.com with esmtp (Exim 4.86_2 #2 (Debian)) id 1hnOF5-0003Jn-Rw for ; Tue, 16 Jul 2019 14:15:43 +0000 Received: from loganberry.canonical.com (localhost [127.0.0.1]) by loganberry.canonical.com (Postfix) with ESMTP id CC7232E80D4 for ; Tue, 16 Jul 2019 14:15:43 +0000 (UTC) MIME-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Date: Tue, 16 Jul 2019 14:01:33 -0000 From: =?utf-8?q?Alex_Benn=C3=A9e?= To: qemu-devel@nongnu.org X-Launchpad-Notification-Type: bug X-Launchpad-Bug: product=qemu; status=Confirmed; importance=Undecided; assignee=None; X-Launchpad-Bug-Tags: linux-user ppc X-Launchpad-Bug-Information-Type: Public X-Launchpad-Bug-Private: no X-Launchpad-Bug-Security-Vulnerability: no X-Launchpad-Bug-Commenters: ajbennee alex-bennee scherft X-Launchpad-Bug-Reporter: Daan Scherft (scherft) X-Launchpad-Bug-Modifier: =?utf-8?q?Alex_Benn=C3=A9e_=28ajbennee=29?= References: <156318593102.28533.3075291509963886255.malonedeb@chaenomeles.canonical.com> Message-Id: <20190716140133.8578-1-alex.bennee@linaro.org> X-Launchpad-Message-Rationale: Subscriber (QEMU) @qemu-devel-ml X-Launchpad-Message-For: qemu-devel-ml Precedence: bulk X-Generated-By: Launchpad (canonical.com); Revision="19007"; Instance="launchpad-lazr.conf" X-Launchpad-Hash: 4e7a2f83538d1c9b8c69941803e0e78d43cd7eed X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 91.189.90.7 Subject: [Qemu-devel] [Bug 1836558] [RFC PATCH for 4.1] linux-user: unparent CPU object before unref X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Bug 1836558 <1836558@bugs.launchpad.net> Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Message-ID: <20190716140133.HWaqsJa-XbG6FMkUKEDZQ4dIwWO1QfmLzo_7d-vl5MY@z> When a CPU object is created it is parented during it's realize stage. If we don't unparent before the "final" unref we will never finzalize the object leading to a memory leak. For most setups you probably won't notice but with anything that creates and destroys a lot of threads this will add up. This goes especially for architectures which allocate a lot of memory in their CPU structures. Fixes: https://bugs.launchpad.net/qemu/+bug/1836558 Cc: 1836558@bugs.launchpad.net Signed-off-by: Alex Benn=C3=A9e --- linux-user/syscall.c | 1 + 1 file changed, 1 insertion(+) diff --git a/linux-user/syscall.c b/linux-user/syscall.c index 39a37496fed..4c9313fd9d0 100644 --- a/linux-user/syscall.c +++ b/linux-user/syscall.c @@ -7183,6 +7183,7 @@ static abi_long do_syscall1(void *cpu_env, int num, a= bi_long arg1, NULL, NULL, 0); } thread_cpu =3D NULL; + object_unparent(OBJECT(cpu)); object_unref(OBJECT(cpu)); g_free(ts); rcu_unregister_thread(); -- = 2.20.1 -- = You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/1836558 Title: Qemu-ppc Memory leak creating threads Status in QEMU: Confirmed Bug description: When creating c++ threads (with c++ std::thread), the resulting binary has memory leaks when running with qemu-ppc. Eg the following c++ program, when compiled with gcc, consumes more and more memory while running at qemu-ppc. (does not have memory leaks when compiling for Intel, when running same binary on real powerpc CPU hardware also no memory leaks). (Note I used function getCurrentRSS to show available memory, see https://stackoverflow.com/questions/669438/how-to-get-memory-usage-at- runtime-using-c; calls commented out here) Compiler: powerpc-linux-gnu-g++ (Debian 8.3.0-2) 8.3.0 (but same problem = with older g++ compilers even 4.9) Os: Debian 10.0 ( Buster) (but same problem seen on Debian 9/stetch) qemu: qemu-ppc version 3.1.50 --- #include #include #include = using namespace std::chrono_literals; // Create/run and join a 100 threads. void Fun100() { // auto b4 =3D getCurrentRSS(); // std::cout << getCurrentRSS() << std::endl; for(int n =3D 0; n < 100; n++) { std::thread t([] { std::this_thread::sleep_for( 10ms ); }); // std::cout << n << ' ' << getCurrentRSS() << std::endl; t.join(); } std::this_thread::sleep_for( 500ms ); // to give OS some time to wipe= memory... // auto after =3D getCurrentRSS(); std::cout << b4 << ' ' << after << std::endl; } = int main(int, char **) { Fun100(); Fun100(); // memory used keeps increasing } To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/1836558/+subscriptions