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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 255AAC433E0 for ; Wed, 10 Feb 2021 18:55:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D777564E2E for ; Wed, 10 Feb 2021 18:55:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234317AbhBJSy6 (ORCPT ); Wed, 10 Feb 2021 13:54:58 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41564 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234329AbhBJSvw (ORCPT ); Wed, 10 Feb 2021 13:51:52 -0500 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0BAEAC061788; Wed, 10 Feb 2021 10:51:12 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.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=EjxwxHUNaOq23km6417evCVsqogE3nHC3sVFoKbPKg8=; b=cbatPENJ45p15QeKsGBV3IHWYB MYY+XRAjvFdyEP+iDEN7xkSzpBF8JaSpuGwjfgDQQEVoM/xpsvi3INdXoOuJZl4r0QQlnvHCCAciJ K/i0cA3Pwgde9FWWOLhdkA6YYagUEcEIMGbqk7+KZOOQ+qxq6cOSsGyLEBBVqyg8IR/EhcXGSzAi5 DrmHQ7abaKogcEgwxl2IxF8lApwCsy2ypMG647U37oOag2em5SznPVPpv05MjbAzva3gYU3woa/oH +xIIvR6HMXdLr+peIu0bMCI/atrUkCcGpsugia1PXfoSpgp6DYOk2ID3l6Da2Zgsc8BsE+tykWGjN kz8+SQ8Q==; Received: from willy by casper.infradead.org with local (Exim 4.94 #2 (Red Hat Linux)) id 1l9uZg-009FhE-Fm; Wed, 10 Feb 2021 18:50:53 +0000 Date: Wed, 10 Feb 2021 18:50:52 +0000 From: Matthew Wilcox To: Zhou Wang Cc: Greg KH , Andy Lutomirski , linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org, linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org, linux-api@vger.kernel.org, Andrew Morton , Alexander Viro , song.bao.hua@hisilicon.com, jgg@ziepe.ca, kevin.tian@intel.com, jean-philippe@linaro.org, eric.auger@redhat.com, liguozhu@hisilicon.com, zhangfei.gao@linaro.org, Sihang Chen Subject: Re: [RFC PATCH v3 1/2] mempinfd: Add new syscall to provide memory pin Message-ID: <20210210185052.GE308988@casper.infradead.org> References: <1612685884-19514-2-git-send-email-wangzhou1@hisilicon.com> <2e6cf99f-beb6-9bef-1316-5e58fb0aa86e@hisilicon.com> <2237506a-0c98-7ba6-5d5f-b60b637174c5@hisilicon.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <2237506a-0c98-7ba6-5d5f-b60b637174c5@hisilicon.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Feb 09, 2021 at 08:20:18PM +0800, Zhou Wang wrote: > Agree, will add it in next version. No, don't do another version. Jason is right, this approach is wrong. The point of SVA is that it doesn't require the application to do anything special. If jitter from too-frequent page migration is actually a problem, then fix the frequency of page migration. Don't pretend that this particular application is so important that it prevents the kernel from doing its housekeeping.