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=-0.4 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, FSL_HELO_FAKE,MAILING_LIST_MULTI,SPF_PASS,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 EEDBAC004D3 for ; Wed, 24 Oct 2018 05:53:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 877C3206B5 for ; Wed, 24 Oct 2018 05:53:27 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="NHam001B" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 877C3206B5 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.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 S1726521AbeJXOUA (ORCPT ); Wed, 24 Oct 2018 10:20:00 -0400 Received: from mail-wm1-f68.google.com ([209.85.128.68]:51404 "EHLO mail-wm1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726080AbeJXOUA (ORCPT ); Wed, 24 Oct 2018 10:20:00 -0400 Received: by mail-wm1-f68.google.com with SMTP id 143-v6so3951437wmf.1 for ; Tue, 23 Oct 2018 22:53:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=8AYhBPynFCUOh6QKNUizhXb9/o/UCNU5+Ge+DkLqccA=; b=NHam001Bw+nAC4hm7JDAw6m3hMiW2g4sR/wp3LYFid/RJrk/i4dUafWlywq+j6+2PM YO3msFwevFZMOCs2IbGP9mrESsiKDlMrZh+jnJPKokMYazjDFNNhrpSiooDhpdJUlhZs bslpifL8IL+w5MHWgbr0U18EWrcHVqX78JPWX5ZuqFZjlqYtlnxTBDv5ZQi7s134nGE0 8h72CmkCis8UssgN+xGH51gxqt50V2YT88r/Y8pczRGT485DpMjYfUYjPFsuQ4SmRwr7 QSmslu7ipEg/59UIEn/eEcp5/QFZd86bpbtADwV5gMBbJyV1zfJWay2G6wm+H9QiTC0Q +bcA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:from:to:cc:subject:message-id :references:mime-version:content-disposition:in-reply-to:user-agent; bh=8AYhBPynFCUOh6QKNUizhXb9/o/UCNU5+Ge+DkLqccA=; b=rnMWZhf9pAse21FdV1kqw3k4TcnHpmErQV6L3oOnjmR8SyqsJ2Yx2Ng2laF74bhchw 9Cuk4FSyUYSKAxK+iiMSZk9FJXevB6FmGIycP6qZtAm+t9YkErAfqOyI5qGlQLfSet3V deQq+WxIjRKjkn1c9WV/IZ83kowGtWZz7BgKeYHq//3nNIV8m6GE1U9XwOXK20I+n2dJ 3PCNao3KtuW9oTt61XQ6fs9W6YVc2n833qN/e9fP6/uSk0e4FelBEMRtUZz/3PugXCV4 gUIVQaTbBdqmJGpsZAZ7KQjBqW+wJj9LEXit+EinZPamKaGeYEk01pbIG9O2+mrZYBmc f0Tg== X-Gm-Message-State: AGRZ1gLA14dm2Qp1C8cpArD6jhNzAxC90YlADJTd++CDHdzoTS17EvuM 02/u3ldNyt3W0pJQhcAgQOE= X-Google-Smtp-Source: AJdET5evqsbTB8nXrt9eLZ+D/WLV/SIn9Rx9bRNexDwbSDBhN1spF1O5bQBMFTWIAYGoGjoCAnyQ3w== X-Received: by 2002:a1c:3702:: with SMTP id e2-v6mr991535wma.89.1540360402879; Tue, 23 Oct 2018 22:53:22 -0700 (PDT) Received: from gmail.com (2E8B0CD5.catv.pool.telekom.hu. [46.139.12.213]) by smtp.gmail.com with ESMTPSA id i13-v6sm3610651wrn.62.2018.10.23.22.53.21 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Tue, 23 Oct 2018 22:53:22 -0700 (PDT) Date: Wed, 24 Oct 2018 07:53:19 +0200 From: Ingo Molnar To: Rik van Riel Cc: linux-kernel@vger.kernel.org, peterz@infradead.org, kernel-team@fb.com, songliubraving@fb.com, will.deacon@arm.com, hpa@zytor.com, luto@kernel.org, npiggin@gmail.com, Linus Torvalds , Thomas Gleixner , Peter Zijlstra , Borislav Petkov Subject: Re: [PATCH 0/7] x86/mm/tlb: make lazy TLB mode even lazier Message-ID: <20181024055319.GA73309@gmail.com> References: <20180924183759.23955-1-riel@surriel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180924183759.23955-1-riel@surriel.com> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Rik van Riel wrote: > The big thing remaining is the reference count overhead of > the lazy TLB mm_struct, but getting rid of that is rather a > lot of code for a small performance gain. Not quite what > Linus asked for :) BTW., what would be the plan to improve scalability there, is it even possible? Also, it would be nice to integrate some of those workloads into a simple 'perf bench mm' or 'perf bench tlb' subcommand, see tools/perf/bench/ on how to add benchmarking modules. Thanks, Ingo