From patchwork Thu Jun 20 16:07:11 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Gao Xiang X-Patchwork-Id: 11007191 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 7EF09112C for ; Thu, 20 Jun 2019 16:09:17 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 6FDA92834A for ; Thu, 20 Jun 2019 16:09:17 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 63C1C28458; Thu, 20 Jun 2019 16:09:17 +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 DB9D52834A for ; Thu, 20 Jun 2019 16:09:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726740AbfFTQIV (ORCPT ); Thu, 20 Jun 2019 12:08:21 -0400 Received: from szxga07-in.huawei.com ([45.249.212.35]:47508 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726530AbfFTQIV (ORCPT ); Thu, 20 Jun 2019 12:08:21 -0400 Received: from DGGEMS409-HUB.china.huawei.com (unknown [172.30.72.59]) by Forcepoint Email with ESMTP id B325C9B162EE99F7F5CB; Fri, 21 Jun 2019 00:08:18 +0800 (CST) Received: from architecture4.huawei.com (10.140.130.215) by smtp.huawei.com (10.3.19.209) with Microsoft SMTP Server (TLS) id 14.3.439.0; Fri, 21 Jun 2019 00:08:06 +0800 From: Gao Xiang To: Chao Yu , Greg Kroah-Hartman CC: , LKML , , , Chao Yu , Fang Wei , Miao Xie , Du Wei , Gao Xiang Subject: [PATCH v2 0/8] staging: erofs: decompression inplace approach Date: Fri, 21 Jun 2019 00:07:11 +0800 Message-ID: <20190620160719.240682-1-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 This is patch v2 of erofs decompression inplace approach, no major issues observed after v1 preliminarily applied to our products, and changes from v1 are minor, so I drop "RFC" tag from this version. See the bottom lines which are taken from RFC PATCH v1 and describe the principle of these technologies. The series is based on the latest staging-next since all dependencies have already been merged. changelog from v1: - keep Z_EROFS_NR_INLINE_PAGEVECS in unzip_vle.h after switching to new decompression backend; - add some DBG_BUGONs in new decompression backend to observe potential issues; - minor code cleanup. 8<-------- 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_ tradeoff, there is no absolute performance conclusion for all on-market combinations. 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 | 322 ++++++++++++++++++ drivers/staging/erofs/erofs_fs.h | 60 +++- drivers/staging/erofs/inode.c | 12 +- drivers/staging/erofs/internal.h | 52 ++- 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 | 463 ++++++++++++++++++++++++++ 12 files changed, 993 insertions(+), 631 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