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=-0.5 required=3.0 tests=BAYES_00,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, URIBL_BLOCKED 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 01642C48BE6 for ; Wed, 16 Jun 2021 12:13:54 +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 6A04C61245 for ; Wed, 16 Jun 2021 12:13:53 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6A04C61245 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]:48796 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ltUQa-0006rR-F5 for qemu-devel@archiver.kernel.org; Wed, 16 Jun 2021 08:13:52 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:57086) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ltUP8-00062n-BQ for qemu-devel@nongnu.org; Wed, 16 Jun 2021 08:12:22 -0400 Received: from mail-qk1-x72d.google.com ([2607:f8b0:4864:20::72d]:38831) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1ltUP4-0000Gg-2I for qemu-devel@nongnu.org; Wed, 16 Jun 2021 08:12:22 -0400 Received: by mail-qk1-x72d.google.com with SMTP id c138so2289236qkg.5 for ; Wed, 16 Jun 2021 05:12:17 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=AFBKQMTWChP9uxAj6/oVIw5e5q34X3Ft7JeojWOoDKk=; b=SoJ5o1l3d1L6raroIIdyyoDOhnvG+Hsqm0XPvZ/I38mydbwxI2em0iQng5d2LKvnGb BUxGucvSEvy7vQCv/bdPZu1elaJBfLwR7x1RpsT+Bz1Nfjv1p+Rb7w9RT8dReqfxxvfQ fuYyDlJGYM7BR8LZexkn854A+o0PAN3UErHH4/j0h/anroxm2ttTf1oZ3Ht0RrnO2tHv eURSqwMOo0it7KcKVSfk3ih61yWzqY1qpSEY14cjPxW/VBD1/F3XggWNJZNxyqpGZpQF IDcn/0S+kS8Sdre1Hd7O9EkPhU88nlUkqtZ/5PNwIWDNfQEYSiz/0xztXZv0fE6nXKQi F/Og== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=AFBKQMTWChP9uxAj6/oVIw5e5q34X3Ft7JeojWOoDKk=; b=gR0GlTvBBvalCbI2X7I3XD6QHPZqo+lEMA27huIgOSLKSbUZSAEoLlTMEwalqs/CBt L7+VG0AfH7DKhCLCKNjxuBzZNimfEFCJCTj/e6qdwU5/aDXvBZDIiWKur7y4MRu3uCuo R7hSLh7OoQcCgkLVVsu9vy2+mdG+2x7U/fbyfxoEwbPv908IU8ziSrB7di6EyH83hzAO TadYUK2Bq9xK5FnmlRqRPP0v2i+oXobVJcUT7d5eA676OGJSnF5oJIEi7s0Ofdk6F41V wCVuY23pqyS2PvcgX8j27aOt1dpNzcl3ZAflvkg9S8A1nT1pm7eePIz8l9oFKombc1vy 1XAg== X-Gm-Message-State: AOAM5304kaYOFzEzDLI7XZbafjGguZT6B3SpFnlo9nxEqOYNsC5ES5+0 otQ+KfX+M2SNXvnNGqj55bE= X-Google-Smtp-Source: ABdhPJxJBy8Yl1b5l6DPh4tSrd3CXA5piRMZ74hVA/PKKRqrS4j3iGX4oyNHoISwXLiN6cx9gvMxdA== X-Received: by 2002:a05:620a:29d4:: with SMTP id s20mr4917841qkp.287.1623845536877; Wed, 16 Jun 2021 05:12:16 -0700 (PDT) Received: from [192.168.0.6] (d149-67-175-105.try.wideopenwest.com. [67.149.105.175]) by smtp.gmail.com with ESMTPSA id g2sm1118010qtb.63.2021.06.16.05.12.15 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Wed, 16 Jun 2021 05:12:16 -0700 (PDT) Content-Type: text/plain; charset=utf-8 Mime-Version: 1.0 (Mac OS X Mail 14.0 \(3654.40.0.2.32\)) Subject: Re: tb_flush() calls causing long Windows XP boot times From: Programmingkid In-Reply-To: <9d0b277d-415f-0f4e-3f09-03445f89848f@linaro.org> Date: Wed, 16 Jun 2021 08:12:15 -0400 Content-Transfer-Encoding: quoted-printable Message-Id: References: <1ee4b7cf-d445-6497-705f-510009fc74f8@ilande.co.uk> <874ke4iqf8.fsf@linaro.org> <3D29C466-BB81-4BCA-96E9-A46721B1ED59@gmail.com> <87sg1ogsvj.fsf@linaro.org> <878s3cjyvl.fsf@linaro.org> <4006E151-B420-4925-A6C9-CD036EE559F2@gmail.com> <9d0b277d-415f-0f4e-3f09-03445f89848f@linaro.org> To: Richard Henderson X-Mailer: Apple Mail (2.3654.40.0.2.32) Received-SPF: pass client-ip=2607:f8b0:4864:20::72d; envelope-from=programmingkidx@gmail.com; helo=mail-qk1-x72d.google.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, 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_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: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Peter Maydell , Paolo Bonzini , =?utf-8?Q?Alex_Benn=C3=A9e?= , incoming+qemu-project-qemu-11167699-3xhw7c0pviow7og92yv73e0tr-issue-404@incoming.gitlab.com, QEMU devel list Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" > On Jun 15, 2021, at 9:58 PM, Richard Henderson = wrote: >=20 > On 6/15/21 6:58 AM, Programmingkid wrote: >>> Ahh I misread - so those are the addresses of the routines and not = where >>> it's sticking the breakpoint? >>>=20 >>> I notice from a bit of googling that there is a boot debugger. I = wonder >>> if /nodebug in boot.ini stops this behaviour? >>>=20 >>> = https://docs.microsoft.com/en-us/troubleshoot/windows-server/performance/s= witch-options-for-boot-files >>>=20 >>> --=20 >>> Alex Benn=C3=A9e >> Hi Alex, >> I tried your suggestion of using /nodebug. It did not stop the = tb_flush() function from being called. >=20 > We are not expecting zero calls to tb_flush (it is used for other = things, including buffer full), but we are hoping that it reduces the = frequency of the calls. Agreed. > I'm guessing you didn't immediately see the slowdown vanish, and so = there was no change to the frequency of the calls. Correct. > FWIW, if you switch to the qemu console, you can see how many flushes = have occurred with "info jit". Thank you very much for this information. I'm currently learning about the x86's debug registers D0 to D7. There = are a lot of rules associated with them. So my guess is one or more = rules may not be implemented in QEMU. I will try to test them out in = FreeDOS and compare notes with a real x86 CPU. A possible workaround might be to implement a command line option that = allows the user to specify how often the tb_flush() call is made. When I = eliminated the call I could not find any problems with my VM's. I = understand if this is not possible.=20