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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id C3337C433F5 for ; Mon, 9 May 2022 07:06:24 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 4DB296B0071; Mon, 9 May 2022 03:06:24 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 48B316B0073; Mon, 9 May 2022 03:06:24 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 351E66B0074; Mon, 9 May 2022 03:06:24 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id 260DC6B0071 for ; Mon, 9 May 2022 03:06:24 -0400 (EDT) Received: from smtpin12.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id EB6D63045F for ; Mon, 9 May 2022 07:06:23 +0000 (UTC) X-FDA: 79445321046.12.517C0BD Received: from mail-ua1-f54.google.com (mail-ua1-f54.google.com [209.85.222.54]) by imf30.hostedemail.com (Postfix) with ESMTP id E95808009A for ; Mon, 9 May 2022 07:06:06 +0000 (UTC) Received: by mail-ua1-f54.google.com with SMTP id ay15so5092072uab.9 for ; Mon, 09 May 2022 00:06:23 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=4nABy/WwmzMwuZmffhD8H2mbJjVoupG6/G8WZP2452E=; b=oFJDn5mZF5ZVm9bRo4YllBeAs0l48j1yU+pMUoI9RNUtPb0JR+lHTPtcRp/uFWI781 +Tx261pCzbClXMSp8JsM1I7OPlj3Di95nZ5YQkeX2tKc27iDPiBPfo4KkgEwaXcudYC0 4nPr054mAaZymxLrY5+7WOjyaHlue4LRmA/4s= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=4nABy/WwmzMwuZmffhD8H2mbJjVoupG6/G8WZP2452E=; b=WlPGYTzyF96utzAbaFcoIVQ5LZgEHe+nH8KEvzwyjTuFDG/C8iAr5i+JvgQV2h5xxC osqdNwWOJjDX9ex4knGJrsxao/G9xjA7NkO/d9rlQY2oUKw6gJue/tXtYwuLjHpJYtZf SUjKtgU2aTAVJs52h7CXFzMnqxscpX8xU3zGbvpJVNp7wWoOBZ0mel63zcAjv+wvsXvH xTHD4N/fW3B041qSMWij9vXRe/uxrXWdW84gtMDQpNIuebzJ7Q8wOp120qNE/rZlPECt z0iDKJYav9SM/W2GOdSSFFRm6BHUgb6UOdwLuksSIXZK50uEG0TfCOEM8h8IZ5VGXUHS tGWg== X-Gm-Message-State: AOAM531B2eJZnCMDXaM9YN/z9NyoXjN8cNXtvHkFTXgfL5j8d1J3r62I G5xgZua4L1GbUmwV8OOgVtvcsFIGabmftY+IVGVvYA== X-Google-Smtp-Source: ABdhPJxezk6RimibgF+l625pbSYd0qVhrd+fIiYkFwPeobo8y9oLFH8RjBCxPGLnYfpfNgBqaJ3QjwWpIaFl4M3oxnI= X-Received: by 2002:a9f:3193:0:b0:35d:21ec:4ae1 with SMTP id v19-20020a9f3193000000b0035d21ec4ae1mr7015519uad.100.1652079982549; Mon, 09 May 2022 00:06:22 -0700 (PDT) MIME-Version: 1.0 References: In-Reply-To: From: Hsin-Yi Wang Date: Mon, 9 May 2022 15:05:56 +0800 Message-ID: Subject: Re: squashfs performance regression and readahea To: Matthew Wilcox Cc: "Song, Xiongwei" , "phillip@squashfs.org.uk" , "linux-mm@kvack.org" , "squashfs-devel@lists.sourceforge.net" Content-Type: text/plain; charset="UTF-8" X-Rspamd-Server: rspam10 X-Rspamd-Queue-Id: E95808009A Authentication-Results: imf30.hostedemail.com; dkim=pass header.d=chromium.org header.s=google header.b=oFJDn5mZ; spf=pass (imf30.hostedemail.com: domain of hsinyi@chromium.org designates 209.85.222.54 as permitted sender) smtp.mailfrom=hsinyi@chromium.org; dmarc=pass (policy=none) header.from=chromium.org X-Rspam-User: X-Stat-Signature: 1obgxmaeisfpcduqyok3kfgtrchtd87m X-HE-Tag: 1652079966-153938 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 Mon, May 9, 2022 at 12:45 AM Matthew Wilcox wrote: > > On Sun, May 08, 2022 at 02:46:40PM +0000, Song, Xiongwei wrote: > > I am facing a performance regression on squashfs. There are many squashfs > > partitions on our board. I am doing the operations below on 90 squashfs > > partitions: > > Hi Xiongwei. Thanks for the report. Hsin-Ye and I have been working on > this problem off-list. Hsin-Ye, could you send the latest version? Hi Matthew, This is the patch of the latest version. Since it's just being reviewed halfway done, I posted the patch here, or should I send it to the list directly? Thanks >From 03558dcaab93ed3c32498eb70c7f2b1382b218d6 Mon Sep 17 00:00:00 2001 From: Hsin-Yi Wang Date: Sun, 10 Oct 2021 21:22:25 +0800 Subject: [PATCH] squashfs: implement readahead Implement readahead callback for squashfs. It will read datablocks which cover pages in readahead request. For a few cases it will not mark page as uptodate, including: - file end is 0. - current batch of pages isn't in the same datablock or not enough in a datablock. Otherwise pages will be marked as uptodate. The unhandled pages will be updated by readpage later. Signed-off-by: Hsin-Yi Wang --- fs/squashfs/file.c | 72 +++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 71 insertions(+), 1 deletion(-) diff --git a/fs/squashfs/file.c b/fs/squashfs/file.c index 89d492916dea..20ec48cf97c5 100644 --- a/fs/squashfs/file.c +++ b/fs/squashfs/file.c @@ -39,6 +39,7 @@ #include "squashfs_fs_sb.h" #include "squashfs_fs_i.h" #include "squashfs.h" +#include "page_actor.h" /* * Locate cache slot in range [offset, index] for specified inode. If @@ -494,7 +495,76 @@ static int squashfs_readpage(struct file *file, struct page *page) return 0; } +static void squashfs_readahead(struct readahead_control *ractl) +{ + struct inode *inode = ractl->mapping->host; + struct squashfs_sb_info *msblk = inode->i_sb->s_fs_info; + size_t mask = (1UL << msblk->block_log) - 1; + size_t shift = msblk->block_log - PAGE_SHIFT; + loff_t req_end = readahead_pos(ractl) + readahead_length(ractl); + loff_t start = readahead_pos(ractl) &~ mask; + size_t len = readahead_length(ractl) + readahead_pos(ractl) - start; + struct squashfs_page_actor *actor; + unsigned int nr_pages = 0; + struct page **pages; + u64 block = 0; + int bsize, res, i, index; + int file_end = i_size_read(inode) >> msblk->block_log; + int max_pages = 1UL << shift; + + readahead_expand(ractl, start, (len | mask) + 1); + + if (readahead_pos(ractl) + readahead_length(ractl) < req_end) + return; + + nr_pages = readahead_count(ractl); + pages = kmalloc_array(nr_pages, sizeof(void *), GFP_KERNEL); + if (!pages) + return; + + actor = squashfs_page_actor_init_special(pages, nr_pages, 0); + if (!actor) + goto out; + + for (;;) { + nr_pages = __readahead_batch(ractl, pages, max_pages); + if (!nr_pages) + break; + + if (readahead_pos(ractl) >= i_size_read(inode) || + file_end == 0 || nr_pages < max_pages) + goto skip_pages; + + index = pages[0]->index >> shift; + bsize = read_blocklist(inode, index, &block); + res = squashfs_read_data(inode->i_sb, block, bsize, NULL, + actor); + + if (res >=0 && (pages[nr_pages - 1]->index >> shift) == index) + for (i = 0; i < nr_pages; i++) + SetPageUptodate(pages[i]); + + for (i = 0; i < nr_pages; i++) { + unlock_page(pages[i]); + put_page(pages[i]); + } + } + + kfree(actor); + return; + +skip_pages: + for (i = 0; i < nr_pages; i++) { + unlock_page(pages[i]); + put_page(pages[i]); + } + + kfree(actor); +out: + kfree(pages); +} const struct address_space_operations squashfs_aops = { - .readpage = squashfs_readpage + .readpage = squashfs_readpage, + .readahead = squashfs_readahead }; -- 2.31.0