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=-0.3 required=3.0 tests=DKIM_ADSP_CUSTOM_MED, DKIM_INVALID,DKIM_SIGNED,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 65FA0C433E0 for ; Mon, 25 May 2020 18:40:18 +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 367972071C for ; Mon, 25 May 2020 18:40:18 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="qY7R/v6e" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 367972071C Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:50876 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jdI1J-0003it-C7 for qemu-devel@archiver.kernel.org; Mon, 25 May 2020 14:40:17 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:49124) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jdI0m-0003Dq-0f for qemu-devel@nongnu.org; Mon, 25 May 2020 14:39:44 -0400 Received: from mail-wm1-x343.google.com ([2a00:1450:4864:20::343]:56295) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1jdI0l-0005qF-8j for qemu-devel@nongnu.org; Mon, 25 May 2020 14:39:43 -0400 Received: by mail-wm1-x343.google.com with SMTP id c71so785434wmd.5 for ; Mon, 25 May 2020 11:39:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=vc8C30teLAV9/YfwOKHmHG856DJJps8CQMTIYx+esKY=; b=qY7R/v6eukJ3ynR6yVU/jOM82HnvZnKwqNhSEEm1HncYht/gI32QwgY+erhMTixJF7 SNfc5VIX79c2pSpgWB7lrodPgzeR3Rq+vAxa5TCqf++g++qaptsOplyarfrCUiZ4GWnI JuMqKi9wCHVy5YAFIMjov8PWl8aZzSipsoIl1dwviekKSU0Opwy2pTNO6JUkSJVR1Irb mE0b0oJSd1Ej90IR23/BtAMKet3CF7c/YT4NzJ68SqhLRQuHjjM6jlLMedSfukr2qxnz k4TFutojU3ie0UKwWB5kdPQaK2z3ySfTvaCsM7En7AvzOplTAM1ef7JH6Ff+xTW073po 870g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc:content-transfer-encoding; bh=vc8C30teLAV9/YfwOKHmHG856DJJps8CQMTIYx+esKY=; b=In7iwrSsv5z3hWFswSyO4HmP1e8CBzgcyI2K7kIYOoFzynQuPF1YUi7mxu5W1B/Ry0 1VPN9nOGmz9ss282mDO9z6luXEK2hSWtsQ1SshLNgOdOFSheRD6hSNEaavjufDwUMPfC 1aqG9VXWr2H1b1XD7beAc/2cj1+kiunkAEnuJCtMlVSjBYgrl2iDbwnzz6mh2zpl9uLu cd5FF9/cMs1rciVJ+ojFGQqO2VfQ1nQ3UH3SbaV7OEE7p5JM5JbJDlaT5KdOELHLUqAw n/eJZ1p3HD+J8vUDt8Xi/4I8WXlelR5xrG13x3624p4cJH7H2HafZ7GS+J0W/NQ3r4SH Vc9g== X-Gm-Message-State: AOAM530+j4ychq3dn2BC+UMpJ4eO1etSN1EG35oSBOOfvm2hUPi7pdzU icOF/WvnbcTiqLjDL9f91DAO+65RBLaSNwpzpVg= X-Google-Smtp-Source: ABdhPJxOd0SJWUVFtzbdnHUt8Ss48OWeFGH92zfeOzLBKIGuvY9UJN3snzECFWFMWlNtQ/56387yjUIKziVUHcCqMAY= X-Received: by 2002:a1c:2dc7:: with SMTP id t190mr25130039wmt.129.1590431978500; Mon, 25 May 2020 11:39:38 -0700 (PDT) MIME-Version: 1.0 References: <20200519162144.10831-1-ahmedkhaledkaraman@gmail.com> <4e78400c-42be-08c6-492d-dc5596551efd@linaro.org> In-Reply-To: <4e78400c-42be-08c6-492d-dc5596551efd@linaro.org> From: Aleksandar Markovic Date: Mon, 25 May 2020 20:39:25 +0200 Message-ID: Subject: Re: [PATCH 0/2] Update use_goto_tb() in hppa and rx targets To: Richard Henderson Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Received-SPF: pass client-ip=2a00:1450:4864:20::343; envelope-from=aleksandar.qemu.devel@gmail.com; helo=mail-wm1-x343.google.com X-detected-operating-system: by eggs.gnu.org: No matching host in p0f cache. That's all we know. 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, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_FROM=0.001, RCVD_IN_DNSWL_NONE=-0.0001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001 autolearn=_AUTOLEARN X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Yoshinori Sato , QEMU Developers , Laurent Vivier , Ahmed Karaman , Stefan Hajnoczi , =?UTF-8?B?QWxleCBCZW5uw6ll?= , Richard Henderson Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" =D0=BF=D0=B5=D1=82, 22. =D0=BC=D0=B0=D1=98 2020. =D1=83 05:12 Richard Hende= rson =D1=98=D0=B5 =D0=BD=D0=B0=D0=BF=D0=B8=D1=81= =D0=B0=D0=BE/=D0=BB=D0=B0: > > On 5/21/20 4:32 AM, Ahmed Karaman wrote: > > Does this mean that there is a bug > > in this function for the other targets? > > Yes, I think so. > > > That we have to do the page crossings check in both modes to avoid the > > user-mode failures that you have mentioned above? > > Well, that or we need to fix linux-user/mmap.c to do all the invalidation= s > required. > Hi, Mr. Richard, :) Many thanks for diagnosis, and, more than this, presenting two alternatives for resolution! That mmap()... It has been giving us the hardest time since forever, and it looks it continues to torture us. It looks we are now between a rock and a hard place. I slightly prefer the later (fixing mmap.c) alternative, just from the gut feeling that it is better to fix the problem at its source, rather than to apply (easy, but possibly performance-wise costly) band-aid to some later consequence. But it seem to me that this is as if I say I choose Charybdis, between Scylla and Charybdis. We also risk jumping out of the frying pan into the fire. Adding Laurent, since this is, in essence, a linux-user issue. If nobody objects, I will instruct Ahmed to file a bug in QEMU Bugzilla. Wishing to improve the performance, we found the hard bug... eh... Thanks again to Richard, Aleksandar > > r~ >