From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mike Kravetz Subject: Re: [PATCH 06/10] hugetlbfs: Convert remove_inode_hugepages() to use filemap_get_folios() Date: Fri, 10 Jun 2022 14:56:05 -0700 Message-ID: <6fc6e9de-39c2-3244-ef92-a1de0d390889@oracle.com> References: <20220605193854.2371230-7-willy@infradead.org> <20220610155205.3111213-1-sumanthk@linux.ibm.com> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=message-id : date : subject : to : cc : references : from : in-reply-to : content-type : content-transfer-encoding : mime-version; s=corp-2021-07-09; bh=cig8b+8Fcts7tPleLoHcBBCVvhjVSl8maOTJHh2wqmM=; b=rtue346rIjgYL8zwsPFXQ/v/JyxBkXc7lyalPS/zw2F6ZcTNDBE8g/NGov4dcMgjEW7L qL1ryvK+1cvjGjwMhL7vLlSaNqxjROiIcrL+NgLlWlSWfn/MGpDNc9K5V48AigSVCCPy KhO1w+RCiCgXoiQ3TEOt50uYVvhbwa3URUro8F6wVGuvAAo87JX8oJ4IvJPKkUJQ6bLI Wnnvzh2gZNKh4ydWq0fbM0iuzEN1lDkhelSHX9GwzyUMKtu2PN4SxTg3bwUEeKNFGNSX ke/pIXbLVe9Rm2E3j6534CfN6YjUE3sfXxabzgKSaIzfswmjCHB8200GZ7DCXPOm3a9u 1g== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.onmicrosoft.com; s=selector2-oracle-onmicrosoft-com; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=cig8b+8Fcts7tPleLoHcBBCVvhjVSl8maOTJHh2wqmM=; b=T8CH7oX/j0AaYvjDSqCgciSkT6W5MunMYiX31kg/2DRYpAvhYS+cnOUuevh+ArAIsVpgSFA4gBB/xN3AK5elY3Yd7wyEPoIPPAduCfE8zVoOEXIFf1jZxcOy1cK5anmOL0DJvb6rJs4A6x57pT1UoX8+jumFvVtIXlzJM6QOFW4= Content-Language: en-US In-Reply-To: List-ID: Content-Type: text/plain; charset="us-ascii" To: Matthew Wilcox , Sumanth Korikkar Cc: linux-ext4-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, gerald.schaefer-tEXmvtCZX7AybS5Ee8rs3A@public.gmane.org, gor-tEXmvtCZX7AybS5Ee8rs3A@public.gmane.org, agordeev-tEXmvtCZX7AybS5Ee8rs3A@public.gmane.org, linux-f2fs-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org, linux-fsdevel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, linux-nilfs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org On 6/10/22 14:17, Matthew Wilcox wrote: > On Fri, Jun 10, 2022 at 05:52:05PM +0200, Sumanth Korikkar wrote: >> To reproduce: >> * clone libhugetlbfs: >> * Execute, PATH=$PATH:"obj64/" LD_LIBRARY_PATH=../obj64/ alloc-instantiate-race shared > > ... it's a lot harder to set up hugetlb than that ... > > anyway, i figured it out without being able to run the reproducer. > > Can you try this? I can confirm that libhugetlbfs tests do not trigger the BUG with the below change. -- Mike Kravetz > > diff --git a/mm/filemap.c b/mm/filemap.c > index a30587f2e598..8ef861297ffb 100644 > --- a/mm/filemap.c > +++ b/mm/filemap.c > @@ -2160,7 +2160,11 @@ unsigned filemap_get_folios(struct address_space *mapping, pgoff_t *start, > if (xa_is_value(folio)) > continue; > if (!folio_batch_add(fbatch, folio)) { > - *start = folio->index + folio_nr_pages(folio); > + unsigned long nr = folio_nr_pages(folio); > + > + if (folio_test_hugetlb(folio)) > + nr = 1; > + *start = folio->index + nr; > goto out; > } > } >