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=-3.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,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 58381C433E7 for ; Tue, 13 Oct 2020 05:36:53 +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 3F9BA208FE for ; Tue, 13 Oct 2020 05:36:52 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=gibson.dropbear.id.au header.i=@gibson.dropbear.id.au header.b="oCFtHRve" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3F9BA208FE Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=gibson.dropbear.id.au Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:33538 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kSCzT-00051O-8h for qemu-devel@archiver.kernel.org; Tue, 13 Oct 2020 01:36:51 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:48518) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kSCyh-0004DW-0d; Tue, 13 Oct 2020 01:36:03 -0400 Received: from bilbo.ozlabs.org ([2401:3900:2:1::2]:36245 helo=ozlabs.org) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kSCye-0006ph-Km; Tue, 13 Oct 2020 01:36:02 -0400 Received: by ozlabs.org (Postfix, from userid 1007) id 4C9PQy5B5Rz9sTr; Tue, 13 Oct 2020 16:35:54 +1100 (AEDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gibson.dropbear.id.au; s=201602; t=1602567354; bh=ohphu5M/BSTRL24nVNhXV9XyHODbES+uWCGzWuYevhU=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=oCFtHRveU0mNRz/klp5jXZvQOnbvOGEYe9FNGCfH09QvV1SUGzGI7aI+9wJxoQaiw OIXHoQdJnK1MNV+niMZz41+Pd802aozeBibGNhCG8NVSzbgUtDThbJJa4sotNdhSwU m/WWUCTGVFlQDxANYl6NYlHX0inLoIMNjPyJgEXA= Date: Tue, 13 Oct 2020 16:32:50 +1100 From: David Gibson To: Paolo Bonzini Subject: Re: [PATCH] hw/net: move allocation to the heap due to very large stack frame Message-ID: <20201013053250.GV71119@yekko.fritz.box> References: <8f07132478469b35fb50a4706691e2b56b10a67b.camel@gmail.com> <20201010060745.GK1025389@yekko.fritz.box> <20201012053001.GD4787@yekko.fritz.box> <38d5993e-8a10-0fb1-5263-6531a356fefd@redhat.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="dRgc669pgRVB2OqT" Content-Disposition: inline In-Reply-To: Received-SPF: pass client-ip=2401:3900:2:1::2; envelope-from=dgibson@ozlabs.org; helo=ozlabs.org X-detected-operating-system: by eggs.gnu.org: No matching host in p0f cache. That's all we know. X-Spam_score_int: -17 X-Spam_score: -1.8 X-Spam_bar: - X-Spam_report: (-1.8 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, HEADER_FROM_DIFFERENT_DOMAINS=0.25, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=no 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: Thomas Huth , qemu-trivial@nongnu.org, jasowang@redhat.com, qemu-devel@nongnu.org, qemu-ppc@nongnu.org, Elena Afanasova Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" --dRgc669pgRVB2OqT Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Oct 12, 2020 at 03:45:02PM +0200, Paolo Bonzini wrote: > On 12/10/20 12:44, Thomas Huth wrote: > > I think this is one of the tasks from: > >=20 > > https://wiki.qemu.org/Contribute/BiteSizedTasks#Compiler-driven_cleanu= ps > >=20 > > It has been added by Paolo in 2016: > >=20 > > https://wiki.qemu.org/index.php?title=3DContribute/BiteSizedTasks&diff= =3D5368&oldid=3D5367 > >=20 > > ... so maybe Paolo can comment on the size that has been chosen here...? >=20 > I used 16K, mostly because it is a nice round number. 8k is too small > due to PATH_MAX-sized variables. 16k seemed to be plenty and triggered > in few-enough places that the cleanup is viable. Ok. Why are large stack frames bad in qemu? --=20 David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson --dRgc669pgRVB2OqT Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEEdfRlhq5hpmzETofcbDjKyiDZs5IFAl+FPAAACgkQbDjKyiDZ s5IruA/+JK7ojWXQ59ESgaHBg2dDtFwnSvbOTRQQ42kh7pgvfT7lsQ+UfPJMc/Sh P5J4GiLBqT456nq0HiUGEY63iHDO1Cs7GzoNOktesvOSXRhN2peCALwfgGLApcnz cxXrWfZWnrr+iCp81YHJ5dlzQr+byBx/3AIwGcxWRnQ9G/mmcH6b+w7aNVTsuHpy uUhhJrYeKrQ9ZklGhHw4ZgoH7VDB8Sn2Ebu45bJv+mqU+gzQ3mr5aw1nmOj+R0D4 zm8GtNkG3FnVv7vqj1M4wouOKtrTBXpsf7SRlFlzGiBGOyRYE96x0bWxqLpiql8x k/WLBozKZfRYzMKBi1xcEeWmlYLTNN04qVmXltVGgM6YQj4TNiGmre6MGSgyejXy EdRaIPrD9l1IfsKuq5UBYpkja/4YSxtJ4X+dK2LbIegmSXw7ZaHtAPmKIZBllgGM +WOJ2dsz5a3F51Ue1WriO59W5zcQN/jFEVvzVh/LZyGNdbg1UXpiqxFmdRESRwM8 hcWtPDLkmM++8fRbV5+44YKvDgOXtXUy04tBAIwl8nCbAKuEwO5jnxSfoNCzcpOY Ln28JA7vtu1R9wlI4YiZQjQ2gyKD40uAj0rwbWTWFh/EIlUK/1Tupxunxi+26yuW 8KdY/0pYKPuGQ7dt1+cHqp/6vjEnTyzrJ3DdlQDoKxuBWtxjPyg= =8cXA -----END PGP SIGNATURE----- --dRgc669pgRVB2OqT--