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 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 14952C07E95 for ; Wed, 7 Jul 2021 07:16:14 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 8101B61C7F for ; Wed, 7 Jul 2021 07:16:13 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8101B61C7F 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 585A36B0036; Wed, 7 Jul 2021 03:16:13 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 50E636B005D; Wed, 7 Jul 2021 03:16:13 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 361966B006C; Wed, 7 Jul 2021 03:16:13 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0253.hostedemail.com [216.40.44.253]) by kanga.kvack.org (Postfix) with ESMTP id F17BD6B0036 for ; Wed, 7 Jul 2021 03:16:12 -0400 (EDT) Received: from smtpin07.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 3E18B8249980 for ; Wed, 7 Jul 2021 07:16:12 +0000 (UTC) X-FDA: 78334932984.07.0DA3F71 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf30.hostedemail.com (Postfix) with ESMTP id 73F61E0016B5 for ; Wed, 7 Jul 2021 07:16:11 +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=qgP4dqrgrNAWWYzN10vwwnL4jCkYS3ZFGuIkGEq6E6Q=; b=gtmh+CfiK9rsRm6VYrmNHuTvRm ARTQH0d1hYpQuDRcfmJgPi44o72pVtbs+wBK4UE1cq6IUzBnP1jr6fPRczUxDcfb6jNck4axxz90/ L3/U9JouDFpeORcCICMtvyBmnvMsiCh6W4YyffyqahvDhc1HpBe1+/JuVvNVvGeGHB2IWmJr/7Ss+ 9V4waSHitW/XIWmSxAuhX7zNiZGlX26gIscWK6nnwKn/tHakF+xcXYOiOvPzpElSyp//yDog33hS0 4rga9++ADk+dZkdfiEW0jf4QKum0GChNKiySl4V7/VVU5tb9VvGgreZOjT4gZ/aDXeyPyFqG4owXD e/hN2ZbQ==; Received: from hch by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1m11lX-00C9Tz-Ir; Wed, 07 Jul 2021 07:14:43 +0000 Date: Wed, 7 Jul 2021 08:14:39 +0100 From: Christoph Hellwig To: Christian K??nig Cc: Christoph Hellwig , John Stultz , lkml , Daniel Vetter , Sumit Semwal , Liam Mark , Chris Goldsworthy , Laura Abbott , Brian Starkey , Hridya Valsaraju , Suren Baghdasaryan , Sandeep Patil , Daniel Mentz , ??rjan Eide , Robin Murphy , Ezequiel Garcia , Simon Ser , James Jones , linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org, Mel Gorman , linux-mm@kvack.org Subject: Re: page pools, was Re: [PATCH v9 1/5] drm: Add a sharable drm page-pool implementation Message-ID: References: <20210630013421.735092-1-john.stultz@linaro.org> <20210630013421.735092-2-john.stultz@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 73F61E0016B5 X-Stat-Signature: cmrfybo5a36yf6n5nwjnfe76upm1b9a9 Authentication-Results: imf30.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=gtmh+Cfi; dmarc=none; spf=none (imf30.hostedemail.com: domain of BATV@casper.srs.infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=BATV@casper.srs.infradead.org X-HE-Tag: 1625642171-242673 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 Wed, Jul 07, 2021 at 09:10:26AM +0200, Christian K??nig wrote: > Well, the original code all this is based on already had the comment that > this really belong into the page allocator. > > The key point is traditionally only GPUs used uncached and write-combined > memory in such large quantities that having a pool for them makes sense. > > Because of this we had this separately to reduce the complexity in the page > allocator to handle another set of complexity of allocation types. > > For the upside, for those use cases it means huge performance improvements > for those drivers. See the numbers John provided in the cover letter. > > But essentially at least I would be totally fine moving this into the page > allocator, but moving it outside of TTM already helps with this goal. So > this patch set is certainly a step into the right direction. Unless I'm badly misreading the patch and this series there is nothing about cache attributes in this code. It just allocates pages, zeroes them, eventually hands them out to a consumer and registers a shrinker for its freelist. If OTOH it actually dealt with cachability that should be documented in the commit log and probably also the naming of the implementation.