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=-4.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 C0130C04EB9 for ; Wed, 5 Dec 2018 05:48:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 85DD7206B7 for ; Wed, 5 Dec 2018 05:48:48 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="JLarozb1" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 85DD7206B7 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=chromium.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727010AbeLEFsr (ORCPT ); Wed, 5 Dec 2018 00:48:47 -0500 Received: from mail-pl1-f195.google.com ([209.85.214.195]:46260 "EHLO mail-pl1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726092AbeLEFsq (ORCPT ); Wed, 5 Dec 2018 00:48:46 -0500 Received: by mail-pl1-f195.google.com with SMTP id t13so9496709ply.13 for ; Tue, 04 Dec 2018 21:48:46 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=jlAgOUx+d9y4Koxz93q6parhhjhH4dXwDaeTxxP4nP8=; b=JLarozb1MoFj2iMfg32xnjapXOlEmjo9r3TV0J+hBfRbOOmqKETxBnc00LeEsw+vm0 0lGXJEwWat/3MZeQfKcHirJYh9v82fkKBNOqII0K95iE5kfWgDpEV8M/zzzbjq3VhxYF 04YxrC5+/zPLkcH+nofCQ656iGKoites41d8A= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=jlAgOUx+d9y4Koxz93q6parhhjhH4dXwDaeTxxP4nP8=; b=kDpSouxGjomcMoq5R12iW3T47bn2AzdjNJ/5PdXmm1oighbPjVhLXpHsiczY0ELdl5 pShmGFFYv7fS0fc0fhSfhCMI6NnWmqx8X3IrYcdKRS+lj0hpAKaR1/cZljtH1tUZAlPn 8pYRe+1bA2RXAW7KkM21KMBVDqELPXF5r9OIsDwvH7cABCUP6wizu5uleL2s6i4F0Zod 5Bv8oiO/2rifpdPZ7+a0ZXwJZaLFjY49TQF0+ORgQWlXrgaefBaZFt1C5BWUBgJfwZIX sQT8due6WIKluphcWSV0HgsjTavyvWySFfOtZvKrP/acjuUca5hmRW6kKmFrwWP51Q96 gBLQ== X-Gm-Message-State: AA+aEWaAL00XlElBabI2rZOPGGHIVLflKhPV/8a01R7hjH6/Bi3roenE /ggUcv2vNC89RwKLV2j/0cp4EA== X-Google-Smtp-Source: AFSGD/XGIJEFyfrfyg8OULqJMVs+IAQFRiR6jXi3pWWWNF4H9mhmgzh0A9r92Lrx+0cfo5I3yXVu/g== X-Received: by 2002:a17:902:ac1:: with SMTP id 59mr3053408plp.36.1543988926074; Tue, 04 Dec 2018 21:48:46 -0800 (PST) Received: from drinkcat2.tpe.corp.google.com ([2401:fa00:1:b:f659:7f17:ea11:4e8e]) by smtp.gmail.com with ESMTPSA id 4sm30806513pfq.10.2018.12.04.21.48.42 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 04 Dec 2018 21:48:45 -0800 (PST) From: Nicolas Boichat To: Will Deacon Cc: Robin Murphy , Joerg Roedel , Christoph Lameter , Pekka Enberg , David Rientjes , Joonsoo Kim , Andrew Morton , Vlastimil Babka , Michal Hocko , Mel Gorman , Levin Alexander , Huaisheng Ye , Mike Rapoport , linux-arm-kernel@lists.infradead.org, iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Yong Wu , Matthias Brugger , Tomasz Figa , yingjoe.chen@mediatek.com, hch@infradead.org, Matthew Wilcox Subject: [PATCH v4 0/3] iommu/io-pgtable-arm-v7s: Use DMA32 zone for page tables Date: Wed, 5 Dec 2018 13:48:25 +0800 Message-Id: <20181205054828.183476-1-drinkcat@chromium.org> X-Mailer: git-send-email 2.20.0.rc1.387.gf8505762e3-goog MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This is a follow-up to the discussion in [1], [2]. IOMMUs using ARMv7 short-descriptor format require page tables (level 1 and 2) to be allocated within the first 4GB of RAM, even on 64-bit systems. For L1 tables that are bigger than a page, we can just use __get_free_pages with GFP_DMA32 (on arm64 systems only, arm would still use GFP_DMA). For L2 tables that only take 1KB, it would be a waste to allocate a full page, so we considered 3 approaches: 1. This series, adding support for GFP_DMA32 slab caches. 2. genalloc, which requires pre-allocating the maximum number of L2 page tables (4096, so 4MB of memory). 3. page_frag, which is not very memory-efficient as it is unable to reuse freed fragments until the whole page is freed. [3] This series is the most memory-efficient approach. [1] https://lists.linuxfoundation.org/pipermail/iommu/2018-November/030876.html [2] https://lists.linuxfoundation.org/pipermail/iommu/2018-December/031696.html [3] https://patchwork.codeaurora.org/patch/671639/ Changes since v1: - Add support for SLAB_CACHE_DMA32 in slab and slub (patches 1/2) - iommu/io-pgtable-arm-v7s (patch 3): - Changed approach to use SLAB_CACHE_DMA32 added by the previous commit. - Use DMA or DMA32 depending on the architecture (DMA for arm, DMA32 for arm64). Changes since v2: - Reworded and expanded commit messages - Added cache_dma32 documentation in PATCH 2/3. v3 used the page_frag approach, see [3]. Nicolas Boichat (3): mm: slab/slub: Add check_slab_flags function to check for valid flags mm: Add support for kmem caches in DMA32 zone iommu/io-pgtable-arm-v7s: Request DMA32 memory, and improve debugging Documentation/ABI/testing/sysfs-kernel-slab | 9 ++++++++ drivers/iommu/io-pgtable-arm-v7s.c | 20 +++++++++++++---- include/linux/slab.h | 2 ++ mm/internal.h | 22 +++++++++++++++++-- mm/slab.c | 10 +++------ mm/slab.h | 3 ++- mm/slab_common.c | 2 +- mm/slub.c | 24 +++++++++++++++------ 8 files changed, 70 insertions(+), 22 deletions(-) -- 2.20.0.rc1.387.gf8505762e3-goog