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 X-Spam-Level: X-Spam-Status: No, score=-12.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, UNPARSEABLE_RELAY,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 25476C43464 for ; Thu, 17 Sep 2020 22:00:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D47D4208DB for ; Thu, 17 Sep 2020 22:00:43 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="EbD6kch8" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726002AbgIQWAk (ORCPT ); Thu, 17 Sep 2020 18:00:40 -0400 Received: from userp2130.oracle.com ([156.151.31.86]:41402 "EHLO userp2130.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725858AbgIQWAk (ORCPT ); Thu, 17 Sep 2020 18:00:40 -0400 X-Greylist: delayed 1634 seconds by postgrey-1.27 at vger.kernel.org; Thu, 17 Sep 2020 18:00:39 EDT Received: from pps.filterd (userp2130.oracle.com [127.0.0.1]) by userp2130.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 08HLxfa0047948; Thu, 17 Sep 2020 22:00:09 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=date : from : to : cc : subject : message-id : references : mime-version : content-type : in-reply-to; s=corp-2020-01-29; bh=6Yw7FZiIzqNMwMA8TDvezwmycMynYGKLn2r6WY2pEOw=; b=EbD6kch8pT1TuAXxEK5KBg6sWhumiP8dBYhRXrhlulb3gLkKsGEc7aJUCONX5hy45k6Y TL8vKuIOLDy3PyNkPlkQYIHCxy0z39dlBljGMnyEZklEaPox2lUUZEy1GQMuwQa+AjoK Ns7bV1z7nvf6dLgrLWfbafafy+8aQxZ24Qzl9aDQBAbJEqdDwY4YwwB1ebIjN400Cf2L KbGydDJWVvinIBBPpuRFQQe4CKMgpl9wV6pM6RenuygpFQu/HwkTx7dC7N7vyMQDjWP0 A6jmp82JciizRb4QgkAAwFZGliLHpYUqUbf8OJ6KXet1pZThC+++nMZBELWm7rFLHeHx vg== Received: from aserp3030.oracle.com (aserp3030.oracle.com [141.146.126.71]) by userp2130.oracle.com with ESMTP id 33gnrrc2bu-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Thu, 17 Sep 2020 22:00:09 +0000 Received: from pps.filterd (aserp3030.oracle.com [127.0.0.1]) by aserp3030.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 08HM05EV101966; Thu, 17 Sep 2020 22:00:08 GMT Received: from aserv0122.oracle.com (aserv0122.oracle.com [141.146.126.236]) by aserp3030.oracle.com with ESMTP id 33khpnqfy6-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 17 Sep 2020 22:00:08 +0000 Received: from abhmp0017.oracle.com (abhmp0017.oracle.com [141.146.116.23]) by aserv0122.oracle.com (8.14.4/8.14.4) with ESMTP id 08HM06ng029353; Thu, 17 Sep 2020 22:00:06 GMT Received: from localhost (/67.169.218.210) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Thu, 17 Sep 2020 22:00:06 +0000 Date: Thu, 17 Sep 2020 15:00:03 -0700 From: "Darrick J. Wong" To: "Matthew Wilcox (Oracle)" Cc: linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, Christoph Hellwig , linux-nvdimm@lists.01.org, linux-kernel@vger.kernel.org, Dave Kleikamp , jfs-discussion@lists.sourceforge.net, Dave Chinner Subject: Re: [PATCH v2 5/9] iomap: Support arbitrarily many blocks per page Message-ID: <20200917220003.GN7955@magnolia> References: <20200910234707.5504-1-willy@infradead.org> <20200910234707.5504-6-willy@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200910234707.5504-6-willy@infradead.org> X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9747 signatures=668679 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 malwarescore=0 suspectscore=1 mlxlogscore=999 phishscore=0 mlxscore=0 adultscore=0 spamscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2009170162 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9747 signatures=668679 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 phishscore=0 spamscore=0 lowpriorityscore=0 malwarescore=0 mlxscore=0 bulkscore=0 suspectscore=1 clxscore=1011 mlxlogscore=999 adultscore=0 priorityscore=1501 impostorscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2009170162 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Fri, Sep 11, 2020 at 12:47:03AM +0100, Matthew Wilcox (Oracle) wrote: > Size the uptodate array dynamically to support larger pages in the > page cache. With a 64kB page, we're only saving 8 bytes per page today, > but with a 2MB maximum page size, we'd have to allocate more than 4kB > per page. Add a few debugging assertions. > > Signed-off-by: Matthew Wilcox (Oracle) > Reviewed-by: Dave Chinner Looks ok, Reviewed-by: Darrick J. Wong --D > --- > fs/iomap/buffered-io.c | 22 +++++++++++++++++----- > 1 file changed, 17 insertions(+), 5 deletions(-) > > diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c > index 7fc0e02d27b0..9670c096b83e 100644 > --- a/fs/iomap/buffered-io.c > +++ b/fs/iomap/buffered-io.c > @@ -22,18 +22,25 @@ > #include "../internal.h" > > /* > - * Structure allocated for each page when block size < PAGE_SIZE to track > - * sub-page uptodate status and I/O completions. > + * Structure allocated for each page or THP when block size < page size > + * to track sub-page uptodate status and I/O completions. > */ > struct iomap_page { > atomic_t read_count; > atomic_t write_count; > spinlock_t uptodate_lock; > - DECLARE_BITMAP(uptodate, PAGE_SIZE / 512); > + unsigned long uptodate[]; > }; > > static inline struct iomap_page *to_iomap_page(struct page *page) > { > + /* > + * per-block data is stored in the head page. Callers should > + * not be dealing with tail pages (and if they are, they can > + * call thp_head() first. > + */ > + VM_BUG_ON_PGFLAGS(PageTail(page), page); > + > if (page_has_private(page)) > return (struct iomap_page *)page_private(page); > return NULL; > @@ -45,11 +52,13 @@ static struct iomap_page * > iomap_page_create(struct inode *inode, struct page *page) > { > struct iomap_page *iop = to_iomap_page(page); > + unsigned int nr_blocks = i_blocks_per_page(inode, page); > > - if (iop || i_blocks_per_page(inode, page) <= 1) > + if (iop || nr_blocks <= 1) > return iop; > > - iop = kzalloc(sizeof(*iop), GFP_NOFS | __GFP_NOFAIL); > + iop = kzalloc(struct_size(iop, uptodate, BITS_TO_LONGS(nr_blocks)), > + GFP_NOFS | __GFP_NOFAIL); > spin_lock_init(&iop->uptodate_lock); > attach_page_private(page, iop); > return iop; > @@ -59,11 +68,14 @@ static void > iomap_page_release(struct page *page) > { > struct iomap_page *iop = detach_page_private(page); > + unsigned int nr_blocks = i_blocks_per_page(page->mapping->host, page); > > if (!iop) > return; > WARN_ON_ONCE(atomic_read(&iop->read_count)); > WARN_ON_ONCE(atomic_read(&iop->write_count)); > + WARN_ON_ONCE(bitmap_full(iop->uptodate, nr_blocks) != > + PageUptodate(page)); > kfree(iop); > } > > -- > 2.28.0 >