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 96CF6C433EF for ; Tue, 28 Jun 2022 22:50:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229877AbiF1Wu3 (ORCPT ); Tue, 28 Jun 2022 18:50:29 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49814 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230396AbiF1Wu2 (ORCPT ); Tue, 28 Jun 2022 18:50:28 -0400 Received: from mail105.syd.optusnet.com.au (mail105.syd.optusnet.com.au [211.29.132.249]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 954DF39833; Tue, 28 Jun 2022 15:50:27 -0700 (PDT) Received: from dread.disaster.area (pa49-181-2-147.pa.nsw.optusnet.com.au [49.181.2.147]) by mail105.syd.optusnet.com.au (Postfix) with ESMTPS id 092A910E7862; Wed, 29 Jun 2022 08:17:58 +1000 (AEST) Received: from dave by dread.disaster.area with local (Exim 4.92.3) (envelope-from ) id 1o6JWv-00CEcF-Ry; Wed, 29 Jun 2022 08:17:57 +1000 Date: Wed, 29 Jun 2022 08:17:57 +1000 From: Dave Chinner To: Matthew Wilcox Cc: "Darrick J. Wong" , linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, Christoph Hellwig , linux-mm@kvack.org Subject: Re: Multi-page folio issues in 5.19-rc4 (was [PATCH v3 25/25] xfs: Support large folios) Message-ID: <20220628221757.GJ227878@dread.disaster.area> References: <20211216210715.3801857-1-willy@infradead.org> <20211216210715.3801857-26-willy@infradead.org> <20220628073120.GI227878@dread.disaster.area> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Optus-CM-Score: 0 X-Optus-CM-Analysis: v=2.4 cv=e9dl9Yl/ c=1 sm=1 tr=0 ts=62bb7e19 a=ivVLWpVy4j68lT4lJFbQgw==:117 a=ivVLWpVy4j68lT4lJFbQgw==:17 a=kj9zAlcOel0A:10 a=JPEYwPQDsx4A:10 a=20KFwNOVAAAA:8 a=7-415B0cAAAA:8 a=I0e5OopBZKVaJ7lt07gA:9 a=CjuIK1q_8ugA:10 a=biEYGPWJfzWAr4FL6Ov7:22 Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org On Tue, Jun 28, 2022 at 02:18:24PM +0100, Matthew Wilcox wrote: > On Tue, Jun 28, 2022 at 12:31:55PM +0100, Matthew Wilcox wrote: > > On Tue, Jun 28, 2022 at 12:27:40PM +0100, Matthew Wilcox wrote: > > > On Tue, Jun 28, 2022 at 05:31:20PM +1000, Dave Chinner wrote: > > > > So using this technique, I've discovered that there's a dirty page > > > > accounting leak that eventually results in fsx hanging in > > > > balance_dirty_pages(). > > > > > > Alas, I think this is only an accounting error, and not related to > > > the problem(s) that Darrick & Zorro are seeing. I think what you're > > > seeing is dirty pages being dropped at truncation without the > > > appropriate accounting. ie this should be the fix: > > > > Argh, try one that actually compiles. > > ... that one's going to underflow the accounting. Maybe I shouldn't > be writing code at 6am? > > diff --git a/mm/huge_memory.c b/mm/huge_memory.c > index f7248002dad9..4eec6ee83e44 100644 > --- a/mm/huge_memory.c > +++ b/mm/huge_memory.c > @@ -18,6 +18,7 @@ > #include > #include > #include > +#include > #include > #include > #include > @@ -2439,11 +2440,15 @@ static void __split_huge_page(struct page *page, struct list_head *list, > __split_huge_page_tail(head, i, lruvec, list); > /* Some pages can be beyond EOF: drop them from page cache */ > if (head[i].index >= end) { > - ClearPageDirty(head + i); > - __delete_from_page_cache(head + i, NULL); > + struct folio *tail = page_folio(head + i); > + > if (shmem_mapping(head->mapping)) > shmem_uncharge(head->mapping->host, 1); > - put_page(head + i); > + else if (folio_test_clear_dirty(tail)) > + folio_account_cleaned(tail, > + inode_to_wb(folio->mapping->host)); > + __filemap_remove_folio(tail, NULL); > + folio_put(tail); > } else if (!PageAnon(page)) { > __xa_store(&head->mapping->i_pages, head[i].index, > head + i, 0); > Yup, that fixes the leak. Tested-by: Dave Chinner Cheers, Dave. -- Dave Chinner david@fromorbit.com