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=-2.1 required=3.0 tests=DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,T_DKIM_INVALID, URIBL_BLOCKED,USER_AGENT_MUTT 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 70BB2ECDFB8 for ; Wed, 18 Jul 2018 18:24:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1CB212084E for ; Wed, 18 Jul 2018 18:24:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="nAMKFq9c" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1CB212084E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729296AbeGRTDZ (ORCPT ); Wed, 18 Jul 2018 15:03:25 -0400 Received: from merlin.infradead.org ([205.233.59.134]:47984 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726556AbeGRTDZ (ORCPT ); Wed, 18 Jul 2018 15:03:25 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=ovTgJXDjiV/784XGqPdj5kGszXVFWaKKl2FdlmdTUR4=; b=nAMKFq9cS6lpnFA1VqKW++gLX T91k+QCnvYJRnZTW0g2n++rWP2fVoL9LioOEteSqtsd2fwEfzOLzyaUiX5lQT0l2tcKkJs1PPf03v 5s6TiHy4esdCi78qqCgVBtM2KquRJ45XJcFirFD5WqI6koGpqU/+b7sbhtOwIg6tGb0WDSb5Ub8y0 IFN7vGtRTejSeyewvCxUCGoSKZ2xNCvAIhox2bFKvIBIt3whVqBCoI90a/lCJyAuB4qSbiQT9Gbq5 INp4z5SLOZ65hKAwlJqnQ8fRcFcCH6suoItLT68tbdMyziWvShOoJhxXOhF1PclYBhZB+5WhiCFZg 8mosVapEA==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=hirez.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.90_1 #2 (Red Hat Linux)) id 1ffr7K-000171-Jt; Wed, 18 Jul 2018 18:24:02 +0000 Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id BE85520275F38; Wed, 18 Jul 2018 20:23:59 +0200 (CEST) Date: Wed, 18 Jul 2018 20:23:59 +0200 From: Peter Zijlstra To: Rik van Riel Cc: songliubraving@fb.com, linux-kernel@vger.kernel.org, dave.hansen@intel.com, hpa@zytor.com, tglx@linutronix.de, mingo@kernel.org, torvalds@linux-foundation.org, linux-tip-commits@vger.kernel.org Subject: Re: [tip:x86/mm] x86/mm/tlb: Make lazy TLB mode lazier Message-ID: <20180718182359.GW2494@hirez.programming.kicks-ass.net> References: <20180716190337.26133-5-riel@surriel.com> <20180717113330.GU2476@hirez.programming.kicks-ass.net> <08AC2AF2-17DE-4416-BBBD-B6B950D20906@surriel.com> <20180718160007.GS2494@hirez.programming.kicks-ass.net> <081E558D-DB34-4A18-A35C-896BC47F6EBA@surriel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <081E558D-DB34-4A18-A35C-896BC47F6EBA@surriel.com> User-Agent: Mutt/1.10.0 (2018-05-17) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jul 18, 2018 at 01:22:19PM -0400, Rik van Riel wrote: > > On Jul 18, 2018, at 12:00 PM, Peter Zijlstra wrote: > > Also, I don't suppose you've looked at the paravirt instances of > > flush_tlb_other() ? They don't elide the flushes because of lazy. > > Let me look at those now :) > kvm_flush_tlb_other takes out preempted VCPUs from the flush mask, > before calling native_flush_tlb_others, so it should get the optimization > automatically. Ah, ok. I wasn't entirely sure the new lazy was purely for the idle case. But yes, the KVM paravirt thing should get the idle case right. > Hyperv does ... sad magic. Yeah,.. it got us to switch to 'rcu' freeing of page-tables and enabled the kvm thing though, so that all is good :-)