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=-3.6 required=3.0 tests=BAYES_00,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 0BAE0C433DB for ; Wed, 10 Feb 2021 18:51:24 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 6345664E2A for ; Wed, 10 Feb 2021 18:51:23 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6345664E2A Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id C00626B006E; Wed, 10 Feb 2021 13:51:22 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id BB0DB6B0070; Wed, 10 Feb 2021 13:51:22 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id AA01A6B0071; Wed, 10 Feb 2021 13:51:22 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0236.hostedemail.com [216.40.44.236]) by kanga.kvack.org (Postfix) with ESMTP id 8AA426B006E for ; Wed, 10 Feb 2021 13:51:22 -0500 (EST) Received: from smtpin22.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 0FC62A749 for ; Wed, 10 Feb 2021 18:51:20 +0000 (UTC) X-FDA: 77803251120.22.DD87BFA Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf26.hostedemail.com (Postfix) with ESMTP id 0AEB840001DE for ; Wed, 10 Feb 2021 18:51:15 +0000 (UTC) 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> X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: 0AEB840001DE X-Stat-Signature: 3xd6g65sg4xrepnq6h6j7mqys6wp3yiy Received-SPF: none (infradead.org>: No applicable sender policy available) receiver=imf26; identity=mailfrom; envelope-from=""; helo=casper.infradead.org; client-ip=90.155.50.34 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1612983075-396714 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: 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.