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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 152F3CA9EA3 for ; Fri, 18 Oct 2019 07:09:42 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 82E5721D80 for ; Fri, 18 Oct 2019 07:09:41 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 82E5721D80 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.ibm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id E480B8E000B; Fri, 18 Oct 2019 03:09:40 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id DD1138E0003; Fri, 18 Oct 2019 03:09:40 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id CBE518E000B; Fri, 18 Oct 2019 03:09:40 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0155.hostedemail.com [216.40.44.155]) by kanga.kvack.org (Postfix) with ESMTP id A49348E0003 for ; Fri, 18 Oct 2019 03:09:40 -0400 (EDT) Received: from smtpin12.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with SMTP id 45E548138 for ; Fri, 18 Oct 2019 07:09:40 +0000 (UTC) X-FDA: 76056030120.12.paint89_5461703e58643 X-HE-Tag: paint89_5461703e58643 X-Filterd-Recvd-Size: 5084 Received: from mx0a-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) by imf30.hostedemail.com (Postfix) with ESMTP for ; Fri, 18 Oct 2019 07:09:39 +0000 (UTC) Received: from pps.filterd (m0098420.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x9I78HV4022035 for ; Fri, 18 Oct 2019 03:09:39 -0400 Received: from e06smtp01.uk.ibm.com (e06smtp01.uk.ibm.com [195.75.94.97]) by mx0b-001b2d01.pphosted.com with ESMTP id 2vq6hpv20c-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Fri, 18 Oct 2019 03:09:38 -0400 Received: from localhost by e06smtp01.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Fri, 18 Oct 2019 08:09:32 +0100 Received: from d06av25.portsmouth.uk.ibm.com (d06av25.portsmouth.uk.ibm.com [9.149.105.61]) by b06cxnps4076.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x9I79WVa54657042 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 18 Oct 2019 07:09:32 GMT Received: from d06av25.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 00C3B11C054; Fri, 18 Oct 2019 07:09:32 +0000 (GMT) Received: from d06av25.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 97BF911C050; Fri, 18 Oct 2019 07:09:31 +0000 (GMT) Received: from ozlabs.au.ibm.com (unknown [9.192.253.14]) by d06av25.portsmouth.uk.ibm.com (Postfix) with ESMTP; Fri, 18 Oct 2019 07:09:31 +0000 (GMT) Received: from [10.61.2.125] (haven.au.ibm.com [9.192.254.114]) (using TLSv1.2 with cipher AES128-SHA (128/128 bits)) (No client certificate requested) by ozlabs.au.ibm.com (Postfix) with ESMTPSA id 74FE2A022E; Fri, 18 Oct 2019 18:09:29 +1100 (AEDT) Subject: Re: [PATCH v3 06/15] powerpc/32: prepare for CONFIG_VMAP_STACK To: Christophe Leroy , Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , npiggin@gmail.com, dja@axtens.net Cc: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-mm@kvack.org References: <7e9771a56539c58dcd8a871c3dfbe7a932e427b0.1568106758.git.christophe.leroy@c-s.fr> From: Andrew Donnellan Date: Fri, 18 Oct 2019 18:09:29 +1100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.9.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-AU X-TM-AS-GCONF: 00 x-cbid: 19101807-4275-0000-0000-000003733550 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19101807-4276-0000-0000-000038865061 Message-Id: X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-10-18_02:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=681 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1908290000 definitions=main-1910180068 Content-Transfer-Encoding: quoted-printable X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On 18/10/19 5:46 pm, Christophe Leroy wrote: >=20 >=20 > Le 17/10/2019 =C3=A0 09:36, Andrew Donnellan a =C3=A9crit=C2=A0: >> On 10/9/19 7:16 pm, Christophe Leroy wrote: >>> +#if defined(CONFIG_VMAP_STACK) && CONFIG_THREAD_SHIFT < PAGE_SHIFT >>> +#define THREAD_SHIFT=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 PAGE_= SHIFT >>> +#else >>> =C2=A0 #define THREAD_SHIFT=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0= CONFIG_THREAD_SHIFT >>> +#endif >>> >>> =C2=A0 #define THREAD_SIZE=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 = (1 << THREAD_SHIFT) >>> >> >> Looking at 64-bit book3s: with 64K pages, this results in a=20 >> THREAD_SIZE that's too large for immediate mode arithmetic operations,= =20 >> which is annoying. Hmm. >> >=20 > Which operation are you thinking about ? >=20 > For instance, 'addi' can't be used anymore, but 'addis' can. Right, I didn't look too closely - yes, they're "addi"s. But also=20 DS-form stores: stdu r1,THREAD_SIZE-STACK_FRAME_OVERHEAD(r3) Anyway, this is just the first thing that broke when I wondered whether=20 a ppc64le_defconfig would even build if I just switched on VMAP_STACK,=20 I'll work around it --=20 Andrew Donnellan OzLabs, ADL Canberra ajd@linux.ibm.com IBM Australia Limited