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 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 78FC4C27C76 for ; Wed, 25 Jan 2023 15:59:10 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pKiAb-0003P9-5h; Wed, 25 Jan 2023 10:58:41 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pKiAW-0003Ot-AU for qemu-devel@nongnu.org; Wed, 25 Jan 2023 10:58:36 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pKiAU-0007I3-0w for qemu-devel@nongnu.org; Wed, 25 Jan 2023 10:58:35 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1674662312; h=from:from:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=5aKHz2vd/OVjgEIISCkHcDLZyMV4zX8GXufgYEZIz6g=; b=jR0HPb60Gc4ALt47nB1JvoXiFRJ8+bfXDqxyZ02Gtv97D/aio29/F5TXLiaqFp70BJuv2P MbrmcEyfFbazjmwGmU5mYznjnFIFYApUcaJoiOItLGG1DOWubKAmQx/kX0QTdnf974Hr+1 0GrucbTWSBp2jZHsmJ99iBFcU2xch6k= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-490-yzFz8mUcOMGis3WDqyo4vg-1; Wed, 25 Jan 2023 10:58:29 -0500 X-MC-Unique: yzFz8mUcOMGis3WDqyo4vg-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.rdu2.redhat.com [10.11.54.8]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 13BC6101A52E; Wed, 25 Jan 2023 15:58:29 +0000 (UTC) Received: from redhat.com (unknown [10.33.36.150]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 156D0C15BA0; Wed, 25 Jan 2023 15:58:27 +0000 (UTC) Date: Wed, 25 Jan 2023 15:58:25 +0000 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Emilio Cota , qemu-devel@nongnu.org, Alex =?utf-8?Q?Benn=C3=A9e?= Subject: Re: [PATCH 2/2] tcg: use QTree instead of GTree Message-ID: References: <20230111035536.309885-1-cota@braap.org> <20230111035536.309885-3-cota@braap.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/2.2.9 (2022-11-12) X-Scanned-By: MIMEDefang 3.1 on 10.11.54.8 Received-SPF: pass client-ip=170.10.133.124; envelope-from=berrange@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=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-0.001, SPF_HELO_NONE=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: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Wed, Jan 11, 2023 at 12:34:29PM +0000, Daniel P. Berrangé wrote: > On Tue, Jan 10, 2023 at 10:55:36PM -0500, Emilio Cota wrote: > > qemu-user can hang in a multi-threaded fork. One common > > reason is that when creating a TB, between fork and exec > > we manipulate a GTree whose memory allocator (GSlice) is > > not fork-safe. > > BTW, I just checked latest glib status > > https://gitlab.gnome.org/GNOME/glib/-/issues/1079 > > it appears they're pretty close to deciding to delete the > GSlice impl and always use system malloc. They have now merged the code to delete the GSlice custom allocator. So glib >= 2.76.0 should not exhibit a hang > So if we do take this patch series it'll hopefully be a time > limited thing to carry. So the question is whether the issue is critical enough that we want to carry a workaround for a while, vs telling users to upgrade to newer glib (once 2.76 actually gets released) With regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|