From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 17000 invoked by alias); 26 Jan 2015 10:02:05 -0000 Mailing-List: contact libffi-discuss-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: libffi-discuss-owner@sourceware.org Received: (qmail 16876 invoked by uid 89); 26 Jan 2015 10:01:58 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=-2.8 required=5.0 tests=AWL,SPF_HELO_PASS,T_RP_MATCHES_RCVD autolearn=ham version=3.3.2 X-HELO: mx1.redhat.com Received: from mx1.redhat.com (HELO mx1.redhat.com) (209.132.183.28) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with (AES256-GCM-SHA384 encrypted) ESMTPS; Mon, 26 Jan 2015 10:01:56 +0000 Received: from int-mx11.intmail.prod.int.phx2.redhat.com (int-mx11.intmail.prod.int.phx2.redhat.com [10.5.11.24]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id t0QA1tkZ019877 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL) for ; Mon, 26 Jan 2015 05:01:55 -0500 Received: from zebedee.pink (ovpn-113-114.phx2.redhat.com [10.3.113.114]) by int-mx11.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id t0QA1re8011524; Mon, 26 Jan 2015 05:01:54 -0500 Message-ID: <54C61091.1060609@redhat.com> Date: Mon, 26 Jan 2015 10:02:00 -0000 From: Andrew Haley User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.4.0 MIME-Version: 1.0 To: Richard Henderson , libffi-discuss@sourceware.org Subject: Re: Constant trampoline pages References: <54C28ACB.8030702@redhat.com> In-Reply-To: <54C28ACB.8030702@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-IsSubscribed: yes X-SW-Source: 2015/txt/msg00024.txt.bz2 On 23/01/15 17:54, Richard Henderson wrote: > > Thoughts? It looks a lot better than what we have now. I don't quite get how a single page of allocated trampolines can suffice, though, even after reading the code. The big problem we've had with the dual-mapping trick was how to survive a fork(). I wonder if your scheme could help with that. Andrew.