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=-0.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 8ACD3C47255 for ; Mon, 11 May 2020 07:43:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 63BD32098B for ; Mon, 11 May 2020 07:43:04 +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="kVWkXI+h" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728425AbgEKHnE (ORCPT ); Mon, 11 May 2020 03:43:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60840 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725790AbgEKHnD (ORCPT ); Mon, 11 May 2020 03:43:03 -0400 Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:e::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AF15CC061A0C; Mon, 11 May 2020 00:43:03 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.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; bh=DAesUFHs3+q5GtlegIPJlfeGWtX+Y+hxDiwu9e6F0sY=; b=kVWkXI+hLMTACOSwPqCaOyS2We VFyTICdLnsGOW4GySQeVAHxa/bnE/VB27ScJS0+ibDJVEy3tQvZoSwSNXToYYtW+aLUcLjOiXW9pU f41QUPV25MliC0FCocYSJnQ37unthzZT17mmsih8cG+znSLkJJzOF+BGfz25pBJEbMiyUwJhrXhjR x33YDWAcnzViVhSZQb0c3gKT7+qtWLTufIlevJdS0sXlTBfbTyBpC9QPBrs7ZIX3f3A2At227q3fP 5k51WwJAmlHUvyM5f7JFs0pu1Tcaww4yZFrCp/ZdhnsKGAy+xCihTerrfmBqFVehwvniM7PydMxpy Cc97eILA==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by bombadil.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1jY35J-0007Gl-US; Mon, 11 May 2020 07:42:46 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 386CB303DA0; Mon, 11 May 2020 09:42:43 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 1D4392870C6C3; Mon, 11 May 2020 09:42:43 +0200 (CEST) Date: Mon, 11 May 2020 09:42:43 +0200 From: Peter Zijlstra To: Andy Lutomirski Cc: Joerg Roedel , Joerg Roedel , X86 ML , "H. Peter Anvin" , Dave Hansen , "Rafael J. Wysocki" , Arnd Bergmann , Andrew Morton , Steven Rostedt , Vlastimil Babka , Michal Hocko , LKML , Linux ACPI , linux-arch , Linux-MM Subject: Re: [RFC PATCH 0/7] mm: Get rid of vmalloc_sync_(un)mappings() Message-ID: <20200511074243.GE2957@hirez.programming.kicks-ass.net> References: <20200508144043.13893-1-joro@8bytes.org> <20200508213609.GU8135@suse.de> <20200509175217.GV8135@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-acpi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org On Sat, May 09, 2020 at 12:05:29PM -0700, Andy Lutomirski wrote: > On x86_64, the only real advantage is that the handful of corner cases > that make vmalloc faults unpleasant (mostly relating to vmap stacks) > go away. On x86_32, a bunch of mind-bending stuff (everything your > series deletes but also almost everything your series *adds*) goes > away. There may be a genuine tiny performance hit on 2-level systems > due to the loss of huge pages in vmalloc space, but I'm not sure I > care or that we use them anyway on these systems. And PeterZ can stop > even thinking about RCU. > > Am I making sense? I think it'll work for x86_64 and that is really all I care about :-)