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 4BF0C392CE53 for ; Mon, 12 Dec 2022 11:57:39 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 4BF0C392CE53 Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=redhat.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1670846258; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=11t5VspaDYRailT2aiWMHRkNlOJn6PAv++p9TrPKbPM=; b=DgNZ9u1r449xAvbTrrXk2xnUQYgd7w0NiWHPDDJgxRhYaK7wP5ImBLgO0JooYf3TIA3wno krYceDEwjlZ9k+a6iehZkwYMpnhpRnlJbu5Hq4g4t9FpHBVgMzPNp6ahFA3WvAWR9NUgpY +6XrG9pqNtlWzrkjVaSTlAVrgEYScW0= 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-211-z3gWRIASOVCqCHTbX5wqbg-1; Mon, 12 Dec 2022 06:57:30 -0500 X-MC-Unique: z3gWRIASOVCqCHTbX5wqbg-1 Received: from smtp.corp.redhat.com (int-mx09.intmail.prod.int.rdu2.redhat.com [10.11.54.9]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id F09651C05EB2; Mon, 12 Dec 2022 11:57:29 +0000 (UTC) Received: from oldenburg.str.redhat.com (unknown [10.2.16.81]) by smtp.corp.redhat.com (Postfix) with ESMTPS id E8299492C14; Mon, 12 Dec 2022 11:57:28 +0000 (UTC) From: Florian Weimer To: Zack Weinberg via Libc-alpha Cc: DJ Delorie , Zack Weinberg Subject: Re: [PATCH] malloc: Use correct C11 atomics for fastbin References: Date: Mon, 12 Dec 2022 12:57:25 +0100 In-Reply-To: (Zack Weinberg via Libc-alpha's message of "Sun, 11 Dec 2022 22:35:25 -0500") Message-ID: <87mt7ssul6.fsf@oldenburg.str.redhat.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/28.1 (gnu/linux) MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.9 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Spam-Status: No, score=-5.0 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_H2,SPF_HELO_NONE,SPF_NONE,TXREP 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: * Zack Weinberg via Libc-alpha: >> * The current malloc knows a lot about glibc internals like pthreads and >> fork, so as to manage those boundaries properly (thread start/stop, >> etc). > > Similarly I am wondering how _this_ manages to work with LD_PRELOADed > malloc replacements. (I confess I haven=E2=80=99t ever dug into this par= t of > glibc much at all.) We call malloc as part of pthread_create, which ensures single-threaded initialization of replacement mallocs. Otherwise, it's up to the replacements to register atfork handlers as needed. Thanks, Florian