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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS 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 DB8F5C43143 for ; Mon, 1 Oct 2018 16:07:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 99B36208AE for ; Mon, 1 Oct 2018 16:07:19 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 99B36208AE Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=surriel.com 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 S1726157AbeJAWpr (ORCPT ); Mon, 1 Oct 2018 18:45:47 -0400 Received: from shelob.surriel.com ([96.67.55.147]:48426 "EHLO shelob.surriel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725735AbeJAWpr (ORCPT ); Mon, 1 Oct 2018 18:45:47 -0400 Received: from imladris.surriel.com ([96.67.55.152]) by shelob.surriel.com with esmtpsa (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.90_1) (envelope-from ) id 1g70j3-0007j0-0q; Mon, 01 Oct 2018 12:07:13 -0400 Message-ID: Subject: Re: [PATCH 1/7] x86/mm/tlb: Always use lazy TLB mode From: Rik van Riel To: Peter Zijlstra Cc: linux-kernel@vger.kernel.org, kernel-team@fb.com, will.deacon@arm.com, songliubraving@fb.com, mingo@kernel.org, luto@kernel.org, hpa@zytor.com, npiggin@gmail.com, Linus Torvalds , Thomas Gleixner , efault@gmx.de Date: Mon, 01 Oct 2018 12:07:12 -0400 In-Reply-To: <20181001155857.GK3439@hirez.programming.kicks-ass.net> References: <20180926035844.1420-1-riel@surriel.com> <20180926035844.1420-2-riel@surriel.com> <20181001155857.GK3439@hirez.programming.kicks-ass.net> Content-Type: multipart/signed; micalg="pgp-sha256"; protocol="application/pgp-signature"; boundary="=-S8P432ZICcoSYajjJTQI" X-Mailer: Evolution 3.28.5 (3.28.5-1.fc28) Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --=-S8P432ZICcoSYajjJTQI Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Mon, 2018-10-01 at 17:58 +0200, Peter Zijlstra wrote: > On Tue, Sep 25, 2018 at 11:58:38PM -0400, Rik van Riel wrote: > > Now that CPUs in lazy TLB mode no longer receive TLB shootdown > > IPIs, except > > at page table freeing time, and idle CPUs will no longer get > > shootdown IPIs > > for things like mprotect and madvise, we can always use lazy TLB > > mode. >=20 > But that's only so at the end of this patch series; either change the > Changelog or the location of this patch? You are right, I should remove that from the changelog. Want me to resend, or would you like to just replace it with something like this: "On most workloads, the number of context switches far exceeds the number of TLB flushes sent. Optimizing the context switches, by always using lazy TLB mode, speeds up those workloads. This patch results in about a 1% reduction in CPU use on a two socket Broadwell system running a memcache like workload." --=20 All Rights Reversed. --=-S8P432ZICcoSYajjJTQI Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part Content-Transfer-Encoding: 7bit -----BEGIN PGP SIGNATURE----- iQEzBAABCAAdFiEEKR73pCCtJ5Xj3yADznnekoTE3oMFAluyRjAACgkQznnekoTE 3oMYSQf+LJYnpkHUgytxcTAOljLyX5/T+SEmbuLkDI/pSpWVyyM7Vqv8E7jk+T3q thX1PSu6i/NahvQE/A23I11CM/GTYo7kxZIbd3AdU9lxChq+BwemkHXKHv5jpRkl 0154AGZLSaaYqQGRN84nhL38v5JpDrTQoBLU2PS6XBSGV3RJpEkEJSyaRC3e+VoO x2tsnZX5TqMRU3IhDxks4uKcW9QwC/Pk7I8DBfghVahDl1w2795CWshX+LlyA2ib 8gnXRIFXTXHS5JMhVsZcAf+3Ig935+U0+eyYnlSSoBMEhEE8uJ7gxL9ZyT4LUe94 k4C51LXP1tjT6q+1lQkZKnjQPV1G8A== =J8G/ -----END PGP SIGNATURE----- --=-S8P432ZICcoSYajjJTQI--