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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 16E8BC4332F for ; Fri, 4 Nov 2022 12:36:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231822AbiKDMg0 (ORCPT ); Fri, 4 Nov 2022 08:36:26 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53368 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231761AbiKDMgZ (ORCPT ); Fri, 4 Nov 2022 08:36:25 -0400 Received: from mail-qv1-xf34.google.com (mail-qv1-xf34.google.com [IPv6:2607:f8b0:4864:20::f34]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1C6A328707 for ; Fri, 4 Nov 2022 05:36:21 -0700 (PDT) Received: by mail-qv1-xf34.google.com with SMTP id e15so3078752qvo.4 for ; Fri, 04 Nov 2022 05:36:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cmpxchg-org.20210112.gappssmtp.com; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=cVKzsOjD+sfLgtcPLOe8okSlSe7+hnLyI1SXbQlGr1s=; b=Xl+hI6yV80ad83IdDSuB/aAZDXDDtn9hvd1CvQ5JEBTksIXBr1kZXmSNNb7ySwqtI7 kvMbnp37uOS5VKMbxbtkmYJb7K/sUSrwgu3y2xx3bnhWuhwSBTB9YLvzBjJRLzkgKtss Ntea5LBo9G+0s4G+Atso9Ic9O4yFGutuvMxIPPtaCrhqrzvw8n1+u/g4UGyIW3H05HVE hPTEeIpjbnwXFzlfYqY7Og/1pSVaIDW+TF5c34O+8s/rpfUIuYn9mfeCWXw40mRXEN5T Ub5FdredG/krZh1kJ8tevx4gvJi0SYth9FbNKWmNqXfG+0/czSiW9KkMSJcalWuINBcT i4MQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=cVKzsOjD+sfLgtcPLOe8okSlSe7+hnLyI1SXbQlGr1s=; b=u2JSu8RJzNMYIlj7vsxmLhzh+1+OfR6QIHRcWFrRk2Zm9PmnTFknu6n+dFL8h+kEzC Q0XUDQA3g5g+zp7gDKx4brygZlMy2u191v6elKkCQIYzkR5qOXx9S5E7Lbkwo0amANwd GV1bIpKyM5f3eY/LuuYpxZavN1aC0fZTJz3X54YGf6Y0keAwwYV2BqutVxc8aeTwy3KL XrLXZ5kejD71Rcb+jtK0KJVyS90CyFHqg/V6Z7r1gVrz4jA0GRPdd/ePAVj6jdgkJQ6I DKBcOxxziVPu5pZR7Bdkp0hFUl4aIGXTXuYE69BqrXFWGQsD7NseXhs8CIuGqG0Je+fE Snkw== X-Gm-Message-State: ACrzQf1TnyjQlfrk7slzA6pYZATzJf3qLzqEeAiaJK1+0grIp4SPjZHU /3cZBVtQNBPspX5nr8IZfK1Org== X-Google-Smtp-Source: AMsMyM7orsCm+qY2qjv712AQbMjBnLx3DSr7IJ18oQAMH2tDtnuRQlxFQq8bAy47Si3WY93+jqxrYA== X-Received: by 2002:a05:6214:2601:b0:4bb:f5ef:998a with SMTP id gu1-20020a056214260100b004bbf5ef998amr24936059qvb.69.1667565380190; Fri, 04 Nov 2022 05:36:20 -0700 (PDT) Received: from localhost ([2620:10d:c091:480::25f1]) by smtp.gmail.com with ESMTPSA id m4-20020ac866c4000000b0039cc7ebf46bsm2302141qtp.93.2022.11.04.05.36.19 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 04 Nov 2022 05:36:19 -0700 (PDT) Date: Fri, 4 Nov 2022 08:36:22 -0400 From: Johannes Weiner To: Andrew Morton Cc: Thorsten Leemhuis , Christoph Hellwig , Jens Axboe , Matthew Wilcox , Suren Baghdasaryan , Chris Mason , Josef Bacik , David Sterba , Gao Xiang , Chao Yu , linux-block@vger.kernel.org, linux-btrfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-erofs@lists.ozlabs.org, linux-mm@kvack.org, "regressions@lists.linux.dev" Subject: Re: [REGESSION] systemd-oomd overreacting due to PSI changes for Btrfs (was: Re: [PATCH 3/5] btrfs: add manual PSI accounting for compressed reads) Message-ID: References: <20220915094200.139713-1-hch@lst.de> <20220915094200.139713-4-hch@lst.de> <5f7bac77-c088-6fb7-ccb5-bef9267f7186@leemhuis.info> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5f7bac77-c088-6fb7-ccb5-bef9267f7186@leemhuis.info> Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Fri, Nov 04, 2022 at 08:32:22AM +0100, Thorsten Leemhuis wrote: > On 03.11.22 23:20, Johannes Weiner wrote: > > Can you try this patch? > > It apparently does the trick -- at least my test setup that usually > triggers the bug within a minute or two survived for nearly an hour now, so: > > Tested-by: Thorsten Leemhuis Great, thanks Thorsten. > Can you please also add this tag to help future archeologists, as > explained by the kernel docs (for details see > Documentation/process/submitting-patches.rst and > Documentation/process/5.Posting.rst): > > Link: > https://lore.kernel.org/r/d20a0a85-e415-cf78-27f9-77dd7a94bc8d@leemhuis.info/ > > It also will make my regression tracking bot see further postings of > this patch and mark the issue as resolved once the patch lands in mainline. Done. Looks like erofs has the same issue, I included a fix for that. Andrew would you mind picking this up and sending it Linusward? Jens routed the series originally, but I believe he is out today. Thanks >From b668b261ed18105e91745f3d7676b6bca968476d Mon Sep 17 00:00:00 2001 From: Johannes Weiner Date: Thu, 3 Nov 2022 17:34:31 -0400 Subject: [PATCH] fs: fix leaked psi pressure state When psi annotations were added to to btrfs compression reads, the psi state tracking over add_ra_bio_pages and btrfs_submit_compressed_read was faulty. A pressure state, once entered, is never left. This results in incorrectly elevated pressure, which triggers OOM kills. pflags record the *previous* memstall state when we enter a new one. The code tried to initialize pflags to 1, and then optimize the leave call when we either didn't enter a memstall, or were already inside a nested stall. However, there can be multiple PageWorkingset pages in the bio, at which point it's that path itself that enters repeatedly and overwrites pflags. This causes us to miss the exit. Enter the stall only once if needed, then unwind correctly. erofs has the same problem, fix that up too. And move the memstall exit past submit_bio() to restore submit accounting originally added by b8e24a9300b0 ("block: annotate refault stalls from IO submission"). Fixes: 4088a47e78f9 ("btrfs: add manual PSI accounting for compressed reads") Fixes: 99486c511f68 ("erofs: add manual PSI accounting for the compressed address space") Fixes: 118f3663fbc6 ("block: remove PSI accounting from the bio layer") Link: https://lore.kernel.org/r/d20a0a85-e415-cf78-27f9-77dd7a94bc8d@leemhuis.info/ Reported-by: Thorsten Leemhuis Signed-off-by: Johannes Weiner Tested-by: Thorsten Leemhuis --- fs/btrfs/compression.c | 14 ++++++++------ fs/erofs/zdata.c | 18 +++++++++++------- 2 files changed, 19 insertions(+), 13 deletions(-) diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c index f1f051ad3147..e6635fe70067 100644 --- a/fs/btrfs/compression.c +++ b/fs/btrfs/compression.c @@ -512,7 +512,7 @@ static u64 bio_end_offset(struct bio *bio) static noinline int add_ra_bio_pages(struct inode *inode, u64 compressed_end, struct compressed_bio *cb, - unsigned long *pflags) + int *memstall, unsigned long *pflags) { struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); unsigned long end_index; @@ -581,8 +581,10 @@ static noinline int add_ra_bio_pages(struct inode *inode, continue; } - if (PageWorkingset(page)) + if (!*memstall && PageWorkingset(page)) { psi_memstall_enter(pflags); + *memstall = 1; + } ret = set_page_extent_mapped(page); if (ret < 0) { @@ -670,8 +672,8 @@ void btrfs_submit_compressed_read(struct inode *inode, struct bio *bio, u64 em_len; u64 em_start; struct extent_map *em; - /* Initialize to 1 to make skip psi_memstall_leave unless needed */ - unsigned long pflags = 1; + unsigned long pflags; + int memstall = 0; blk_status_t ret; int ret2; int i; @@ -727,7 +729,7 @@ void btrfs_submit_compressed_read(struct inode *inode, struct bio *bio, goto fail; } - add_ra_bio_pages(inode, em_start + em_len, cb, &pflags); + add_ra_bio_pages(inode, em_start + em_len, cb, &memstall, &pflags); /* include any pages we added in add_ra-bio_pages */ cb->len = bio->bi_iter.bi_size; @@ -807,7 +809,7 @@ void btrfs_submit_compressed_read(struct inode *inode, struct bio *bio, } } - if (!pflags) + if (memstall) psi_memstall_leave(&pflags); if (refcount_dec_and_test(&cb->pending_ios)) diff --git a/fs/erofs/zdata.c b/fs/erofs/zdata.c index c7f24fc7efd5..064a166324a7 100644 --- a/fs/erofs/zdata.c +++ b/fs/erofs/zdata.c @@ -1412,8 +1412,8 @@ static void z_erofs_submit_queue(struct z_erofs_decompress_frontend *f, struct block_device *last_bdev; unsigned int nr_bios = 0; struct bio *bio = NULL; - /* initialize to 1 to make skip psi_memstall_leave unless needed */ - unsigned long pflags = 1; + unsigned long pflags; + int memstall = 0; bi_private = jobqueueset_init(sb, q, fgq, force_fg); qtail[JQ_BYPASS] = &q[JQ_BYPASS]->head; @@ -1463,14 +1463,18 @@ static void z_erofs_submit_queue(struct z_erofs_decompress_frontend *f, if (bio && (cur != last_index + 1 || last_bdev != mdev.m_bdev)) { submit_bio_retry: - if (!pflags) - psi_memstall_leave(&pflags); submit_bio(bio); + if (memstall) { + psi_memstall_leave(&pflags); + memstall = 0; + } bio = NULL; } - if (unlikely(PageWorkingset(page))) + if (unlikely(PageWorkingset(page)) && !memstall) { psi_memstall_enter(&pflags); + memstall = 1; + } if (!bio) { bio = bio_alloc(mdev.m_bdev, BIO_MAX_VECS, @@ -1500,9 +1504,9 @@ static void z_erofs_submit_queue(struct z_erofs_decompress_frontend *f, } while (owned_head != Z_EROFS_PCLUSTER_TAIL); if (bio) { - if (!pflags) - psi_memstall_leave(&pflags); submit_bio(bio); + if (memstall) + psi_memstall_leave(&pflags); } /* -- 2.38.1