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=-2.2 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 70851C2D0BF for ; Mon, 16 Dec 2019 13:41:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 516C020409 for ; Mon, 16 Dec 2019 13:41:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727972AbfLPNl2 (ORCPT ); Mon, 16 Dec 2019 08:41:28 -0500 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:53150 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727609AbfLPNl2 (ORCPT ); Mon, 16 Dec 2019 08:41:28 -0500 Received: from pps.filterd (m0098421.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id xBGDcUlr076139; Mon, 16 Dec 2019 08:40:40 -0500 Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com with ESMTP id 2wwe8aaw6w-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 16 Dec 2019 08:40:40 -0500 Received: from m0098421.ppops.net (m0098421.ppops.net [127.0.0.1]) by pps.reinject (8.16.0.36/8.16.0.36) with SMTP id xBGDcdLa077440; Mon, 16 Dec 2019 08:40:40 -0500 Received: from ppma03dal.us.ibm.com (b.bd.3ea9.ip4.static.sl-reverse.com [169.62.189.11]) by mx0a-001b2d01.pphosted.com with ESMTP id 2wwe8aaw5x-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 16 Dec 2019 08:40:39 -0500 Received: from pps.filterd (ppma03dal.us.ibm.com [127.0.0.1]) by ppma03dal.us.ibm.com (8.16.0.27/8.16.0.27) with SMTP id xBGDeW0l014885; Mon, 16 Dec 2019 13:40:38 GMT Received: from b01cxnp22035.gho.pok.ibm.com (b01cxnp22035.gho.pok.ibm.com [9.57.198.25]) by ppma03dal.us.ibm.com with ESMTP id 2wvqc689y6-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 16 Dec 2019 13:40:38 +0000 Received: from b01ledav001.gho.pok.ibm.com (b01ledav001.gho.pok.ibm.com [9.57.199.106]) by b01cxnp22035.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id xBGDebSg43385342 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 16 Dec 2019 13:40:37 GMT Received: from b01ledav001.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id BCF2B28058; Mon, 16 Dec 2019 13:40:37 +0000 (GMT) Received: from b01ledav001.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 2CF8028059; Mon, 16 Dec 2019 13:40:32 +0000 (GMT) Received: from [9.199.36.91] (unknown [9.199.36.91]) by b01ledav001.gho.pok.ibm.com (Postfix) with ESMTP; Mon, 16 Dec 2019 13:40:31 +0000 (GMT) Subject: Re: [PATCH 05/17] asm-generic/tlb: Rename HAVE_RCU_TABLE_NO_INVALIDATE To: Peter Zijlstra , Michael Ellerman Cc: Will Deacon , Andrew Morton , Nick Piggin , linux-arch@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Yoshinori Sato , Rich Felker , "David S. Miller" , Helge Deller , Geert Uytterhoeven , Paul Burton , Tony Luck , Richard Henderson , Nick Hu , Paul Walmsley References: <20191211120713.360281197@infradead.org> <20191211122955.940455408@infradead.org> <87woawzc1t.fsf@linux.ibm.com> <20191216123752.GM2844@hirez.programming.kicks-ass.net> <20191216132004.GO2844@hirez.programming.kicks-ass.net> From: "Aneesh Kumar K.V" Message-ID: Date: Mon, 16 Dec 2019 19:10:30 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.2.2 MIME-Version: 1.0 In-Reply-To: <20191216132004.GO2844@hirez.programming.kicks-ass.net> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.95,18.0.572 definitions=2019-12-16_05:2019-12-16,2019-12-16 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 suspectscore=2 bulkscore=0 phishscore=0 lowpriorityscore=0 malwarescore=0 priorityscore=1501 adultscore=0 mlxscore=0 clxscore=1015 mlxlogscore=999 spamscore=0 impostorscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-1910280000 definitions=main-1912160122 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/16/19 6:50 PM, Peter Zijlstra wrote: > On Mon, Dec 16, 2019 at 06:43:53PM +0530, Aneesh Kumar K.V wrote: >> On 12/16/19 6:07 PM, Peter Zijlstra wrote: > >>> I'm confused, are you saing you're happy to have PowerPC eat the extra >>> TLB invalidates? I thought you cared about PPC performance :-) >>> >>> >> >> Instead can we do >> >> static inline void tlb_table_invalidate(struct mmu_gather *tlb) >> { >> #ifndef CONFIG_MMU_GATHER_RCU_TABLE_FREE >> * Invalidate page-table caches used by hardware walkers. Then we still >> * need to RCU-sched wait while freeing the pages because software >> * walkers can still be in-flight. >> */ >> tlb_flush_mmu_tlbonly(tlb); >> #endif >> } > > How does that not break ARM/ARM64/s390 and x86 ? > Hmm I missed that usage of RCU_TABLE_NO_INVALIDATE. Ok I guess we need to revert this change that went upstream this merge window then commit 52162ec784fa05f3a4b1d8e84421279998be3773 Author: Aneesh Kumar K.V Date: Thu Oct 24 13:28:00 2019 +0530 powerpc/mm/book3s64/radix: Use freed_tables instead of need_flush_all I will review the change closely. -aneesh