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. 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=-3.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED 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 3E3B8C433E0 for ; Wed, 10 Feb 2021 18:51:19 +0000 (UTC) Received: from whitealder.osuosl.org (smtp1.osuosl.org [140.211.166.138]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id AC05B64E2A for ; Wed, 10 Feb 2021 18:51:18 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org AC05B64E2A Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from localhost (localhost [127.0.0.1]) by whitealder.osuosl.org (Postfix) with ESMTP id 5ABEB86E38; Wed, 10 Feb 2021 18:51:18 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from whitealder.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id PVywszqH+7dr; Wed, 10 Feb 2021 18:51:17 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by whitealder.osuosl.org (Postfix) with ESMTP id D992A86B3A; Wed, 10 Feb 2021 18:51:17 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id C1B69C0174; Wed, 10 Feb 2021 18:51:17 +0000 (UTC) Received: from whitealder.osuosl.org (smtp1.osuosl.org [140.211.166.138]) by lists.linuxfoundation.org (Postfix) with ESMTP id AA887C0174 for ; Wed, 10 Feb 2021 18:51:15 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by whitealder.osuosl.org (Postfix) with ESMTP id 97D4886E3F for ; Wed, 10 Feb 2021 18:51:15 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from whitealder.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id vOYw0cQqEzDV for ; Wed, 10 Feb 2021 18:51:14 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by whitealder.osuosl.org (Postfix) with ESMTPS id B487386EC3 for ; Wed, 10 Feb 2021 18:51:14 +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 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-Disposition: inline In-Reply-To: <2237506a-0c98-7ba6-5d5f-b60b637174c5@hisilicon.com> Cc: jean-philippe@linaro.org, kevin.tian@intel.com, Sihang Chen , jgg@ziepe.ca, Greg KH , linux-kernel@vger.kernel.org, Andy Lutomirski , linux-mm@kvack.org, iommu@lists.linux-foundation.org, Alexander Viro , linux-api@vger.kernel.org, zhangfei.gao@linaro.org, Andrew Morton , liguozhu@hisilicon.com, linux-arm-kernel@lists.infradead.org X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" 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. _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu 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=-4.3 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 6AD39C433DB for ; Wed, 10 Feb 2021 18:52:15 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 24F6264E32 for ; Wed, 10 Feb 2021 18:52:15 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 24F6264E32 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References:Message-ID: Subject:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=jKimBBVCoFkxGgGziVqQdVbMxCzuFzRsih4Tjy2e0Xg=; b=vMrqje0GukHfus+W6/+JE41Bk HlgVwm554HVsjWp1i/59GGX3nY584qBKYrf9LnvNSNku3jToB7WG4kCob2g7fLGEdzwewN6HzPvUu x58zehcAPbc+LFDTbl0Q91KB594jYUXVS9P59zDhp4GozZ9HNBpXCU3Yhi+1ZyfeM5FfnXuh8G6CD 7KnF9h6DRs2ZzxC5gLX0Ssiy/3WyQXTFiI4CRklnMDNbsibijpcTMreDFHwqu/ljF1ddpG03itRFX SiOUQxKA9pWwbMEqxRLjOLBXNQpqBVXhpJWmQl+yKuk6YYoNqj2a7iOaggEdgiJ2HYqI2pBUdsNuG DMOLASSMw==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1l9uZx-0000nl-8M; Wed, 10 Feb 2021 18:51:09 +0000 Received: from casper.infradead.org ([2001:8b0:10b:1236::1]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1l9uZu-0000n2-Mb for linux-arm-kernel@merlin.infradead.org; Wed, 10 Feb 2021 18:51:06 +0000 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 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-Disposition: inline In-Reply-To: <2237506a-0c98-7ba6-5d5f-b60b637174c5@hisilicon.com> X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: song.bao.hua@hisilicon.com, jean-philippe@linaro.org, kevin.tian@intel.com, Sihang Chen , jgg@ziepe.ca, Greg KH , linux-kernel@vger.kernel.org, Andy Lutomirski , linux-mm@kvack.org, iommu@lists.linux-foundation.org, Alexander Viro , eric.auger@redhat.com, linux-api@vger.kernel.org, zhangfei.gao@linaro.org, Andrew Morton , liguozhu@hisilicon.com, linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.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. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel