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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham 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 B133CC73C56 for ; Tue, 9 Jul 2019 20:09:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 93C372073D for ; Tue, 9 Jul 2019 20:09:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729691AbfGIUJh (ORCPT ); Tue, 9 Jul 2019 16:09:37 -0400 Received: from mx0a-002e3701.pphosted.com ([148.163.147.86]:49280 "EHLO mx0a-002e3701.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726679AbfGIUJh (ORCPT ); Tue, 9 Jul 2019 16:09:37 -0400 Received: from pps.filterd (m0148663.ppops.net [127.0.0.1]) by mx0a-002e3701.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x69K5sfM007998; Tue, 9 Jul 2019 20:09:17 GMT Received: from g2t2354.austin.hpe.com (g2t2354.austin.hpe.com [15.233.44.27]) by mx0a-002e3701.pphosted.com with ESMTP id 2tn15w86pd-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 09 Jul 2019 20:09:17 +0000 Received: from g2t2360.austin.hpecorp.net (g2t2360.austin.hpecorp.net [16.196.225.135]) by g2t2354.austin.hpe.com (Postfix) with ESMTP id 3E52481; Tue, 9 Jul 2019 20:09:16 +0000 (UTC) Received: from hpe.com (ben.americas.hpqcorp.net [10.33.153.7]) by g2t2360.austin.hpecorp.net (Postfix) with ESMTP id A84F739; Tue, 9 Jul 2019 20:09:14 +0000 (UTC) Date: Tue, 9 Jul 2019 15:09:14 -0500 From: Russ Anderson To: Thomas Gleixner Cc: Nadav Amit , Andy Lutomirski , Dave Hansen , x86@kernel.org, LKML , Peter Zijlstra , Ingo Molnar , Dave Hansen , Dimitri Sivanich , Mike Travis , Hedi Berriche Subject: Re: [PATCH v2 8/9] x86/mm/tlb: Remove UV special case Message-ID: <20190709200914.fjvi3cy3qfc6fmis@hpe.com> Reply-To: Russ Anderson References: <20190702235151.4377-1-namit@vmware.com> <20190702235151.4377-9-namit@vmware.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: NeoMutt/20170421 (1.8.2) X-HPE-SCL: -1 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-07-09_08:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=2 phishscore=0 bulkscore=0 spamscore=0 clxscore=1011 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1907090239 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jul 09, 2019 at 09:50:27PM +0200, Thomas Gleixner wrote: > On Tue, 2 Jul 2019, Nadav Amit wrote: > > > SGI UV support is outdated and not maintained, and it is not clear how > > it performs relatively to non-UV. Remove the code to simplify the code. > > You should at least Cc the SGI/HP folks on that. They are still > around. Done so. Thanks Thomas. The SGI UV is now HPE Superdome Flex and is very much still supported. Thanks. > > Cc: Peter Zijlstra > > Cc: Dave Hansen > > Suggested-by: Andy Lutomirski > > Signed-off-by: Nadav Amit > > --- > > arch/x86/mm/tlb.c | 25 ------------------------- > > 1 file changed, 25 deletions(-) > > > > diff --git a/arch/x86/mm/tlb.c b/arch/x86/mm/tlb.c > > index b47a71820f35..64afe1215495 100644 > > --- a/arch/x86/mm/tlb.c > > +++ b/arch/x86/mm/tlb.c > > @@ -689,31 +689,6 @@ void native_flush_tlb_multi(const struct cpumask *cpumask, > > trace_tlb_flush(TLB_REMOTE_SEND_IPI, > > (info->end - info->start) >> PAGE_SHIFT); > > > > - if (is_uv_system()) { > > - /* > > - * This whole special case is confused. UV has a "Broadcast > > - * Assist Unit", which seems to be a fancy way to send IPIs. > > - * Back when x86 used an explicit TLB flush IPI, UV was > > - * optimized to use its own mechanism. These days, x86 uses > > - * smp_call_function_many(), but UV still uses a manual IPI, > > - * and that IPI's action is out of date -- it does a manual > > - * flush instead of calling flush_tlb_func_remote(). This > > - * means that the percpu tlb_gen variables won't be updated > > - * and we'll do pointless flushes on future context switches. > > - * > > - * Rather than hooking native_flush_tlb_multi() here, I think > > - * that UV should be updated so that smp_call_function_many(), > > - * etc, are optimal on UV. > > - */ > > - flush_tlb_func_local(info); > > - > > - cpumask = uv_flush_tlb_others(cpumask, info); > > - if (cpumask) > > - smp_call_function_many(cpumask, flush_tlb_func_remote, > > - (void *)info, 1); > > - return; > > - } > > - > > /* > > * If no page tables were freed, we can skip sending IPIs to > > * CPUs in lazy TLB mode. They will flush the CPU themselves > > -- > > 2.17.1 > > > > -- Russ Anderson, SuperDome Flex Linux Kernel Group Manager HPE - Hewlett Packard Enterprise (formerly SGI) rja@hpe.com