From patchwork Fri Jun 14 18:16:11 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Gao Xiang X-Patchwork-Id: 10996331 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id D1B021395 for ; Fri, 14 Jun 2019 18:17:57 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id C4BDA28748 for ; Fri, 14 Jun 2019 18:17:57 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id B8F7F2874A; Fri, 14 Jun 2019 18:17:57 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 351BA282EC for ; Fri, 14 Jun 2019 18:17:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726305AbfFNSRQ (ORCPT ); Fri, 14 Jun 2019 14:17:16 -0400 Received: from szxga04-in.huawei.com ([45.249.212.190]:18576 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725951AbfFNSRP (ORCPT ); Fri, 14 Jun 2019 14:17:15 -0400 Received: from DGGEMS408-HUB.china.huawei.com (unknown [172.30.72.58]) by Forcepoint Email with ESMTP id 575A9499F4040C8D4004; Sat, 15 Jun 2019 02:17:13 +0800 (CST) Received: from architecture4.huawei.com (10.140.130.215) by smtp.huawei.com (10.3.19.208) with Microsoft SMTP Server (TLS) id 14.3.439.0; Sat, 15 Jun 2019 02:17:02 +0800 From: Gao Xiang To: , Greg Kroah-Hartman , CC: LKML , , , Miao Xie , , Fang Wei , Gao Xiang Subject: [RFC PATCH 0/8] staging: erofs: decompression inplace approach Date: Sat, 15 Jun 2019 02:16:11 +0800 Message-ID: <20190614181619.64905-1-gaoxiang25@huawei.com> X-Mailer: git-send-email 2.17.1 MIME-Version: 1.0 X-Originating-IP: [10.140.130.215] X-CFilter-Loop: Reflected Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Hi, After working on for more than half a year, the detail of erofs decompression inplace is almost determined and ready for linux-next. Currently, inplace IO is used if the whole compressed data is used in order to reduce compressed pages extra memory overhead and an extra memcpy (the only one memcpy) will be used for each inplace IO since temporary buffer is needed to keep decompressing safe for inplace IO. However, most of lz-based decompression algorithms support decompression inplace by their algorithm designs, such as LZ4, LZO, etc. If iend - oend margin is large enough, decompression inplace can be done in the same buffer safely, as illustrated below: start of compressed logical extent | end of this logical extent | | ______v___________________________v________ ... | page 6 | page 7 | page 8 | page 9 | ... |__________|__________|__________|__________| . ^ . ^ . |compressed| . | data | . . . |< dstsize >|| oend iend op ip Fixed-size output compression can make the full use of this feature to reduce memory overhead and avoid extra memcpy compared with fixed-size input compression since iend is strictly not less than oend for fixed-size output compression with inplace IO to last pages. In addition, erofs compression indexes have been improved as well by introducing compacted compression indexes. These two techniques all benefit sequential read (on x86_64, 710.8MiB/s -> 755.4MiB/s; on Kirin980, 725MiB/s -> 812MiB/s) therefore erofs could have similar sequential read performance against ext4 in a larger CR range on high-spend SSD / NVMe devices as well. However, note that it is _cpu vs storage device_ balance, there is no absolute performance conclusion for all on-market combinations. At last, this is RFC patch v1, which means it is not suitable for merging soon... I'm still working on it, testing its stability these days and hope these patches get merged for 5.3 LTS (if 5.3 is a LTS version). The series is based on staging-next with the following patches, which can be merged in advance: [PATCH v3 1/2] staging: erofs: add requirements field in superblock [PATCH v2 2/2] staging: erofs: rename data_mapping_mode to datamode Test images: name size CR enwik9 1000000000 1.00 enwik9_4k.squashfs.img 621211648 1.61 enwik9_4k.erofs.img 558133248 1.79 enwik9_8k.squashfs.img 556191744 1.80 enwik9_16k.squashfs.img 502661120 1.99 enwik9_128k.squashfs.img 398204928 2.51 Test Environment: CPU: Intel(R) Core(TM) i5-8250U CPU @ 1.60GHz (4 cores, 8 threads) DDR: 8G SSD: INTEL SSDPEKKF360G7H Kernel: Linux 5.2-rc3+ (with lz4-1.8.3 algorithm) Test configuration: squashfs: CONFIG_SQUASHFS=y CONFIG_SQUASHFS_FILE_DIRECT=y CONFIG_SQUASHFS_DECOMP_MULTI_PERCPU=y CONFIG_SQUASHFS_LZ4=y CONFIG_SQUASHFS_4K_DEVBLK_SIZE=y erofs: CONFIG_EROFS_FS_USE_VM_MAP_RAM=y CONFIG_EROFS_FS_ZIP=y CONFIG_EROFS_FS_CLUSTER_PAGE_LIMIT=1 CONFIG_EROFS_FS_ZIP_CACHE_BIPOLAR=y with intel_pstate=disable, 8 cpus on at 1801000 scaling_{min,max}_freq, userspace scaling_governor Sequential read results (MiB/s): 1 2 3 4 5 avg enwik9_4k.ext4.img 767 770 738 726 724 745 enwik9_4k.erofs.img 756 745 770 746 760 755.4 enwik9_4k.squashfs.img 90.3 83.0 94.3 90.7 92.6 90.18 enwik9_8k.squashfs.img 111 108 110 108 110 109.4 enwik9_16k.squashfs.img 158 163 146 165 174 161.2 enwik9_128k.squashfs.img 324 314 262 262 296 291.6 Thanks, Gao Xiang Gao Xiang (8): staging: erofs: add compacted ondisk compression indexes staging: erofs: add compacted compression indexes support staging: erofs: move per-CPU buffers implementation to utils.c staging: erofs: move stagingpage operations to compress.h staging: erofs: introduce generic decompression backend staging: erofs: introduce LZ4 decompression inplace staging: erofs: switch to new decompression backend staging: erofs: integrate decompression inplace drivers/staging/erofs/Makefile | 2 +- drivers/staging/erofs/compress.h | 62 ++++ drivers/staging/erofs/data.c | 4 +- drivers/staging/erofs/decompressor.c | 321 ++++++++++++++++++ drivers/staging/erofs/erofs_fs.h | 60 +++- drivers/staging/erofs/inode.c | 12 +- drivers/staging/erofs/internal.h | 58 +++- drivers/staging/erofs/unzip_vle.c | 368 ++------------------ drivers/staging/erofs/unzip_vle.h | 38 +-- drivers/staging/erofs/unzip_vle_lz4.c | 229 ------------- drivers/staging/erofs/utils.c | 12 + drivers/staging/erofs/zmap.c | 462 ++++++++++++++++++++++++++ 12 files changed, 996 insertions(+), 632 deletions(-) create mode 100644 drivers/staging/erofs/compress.h create mode 100644 drivers/staging/erofs/decompressor.c delete mode 100644 drivers/staging/erofs/unzip_vle_lz4.c create mode 100644 drivers/staging/erofs/zmap.c