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=-3.8 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no 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 88A99C433E0 for ; Fri, 7 Aug 2020 13:39:21 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 4414222C9F for ; Fri, 7 Aug 2020 13:39:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="jooGZOBZ" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4414222C9F Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 9BB9A8D00AC; Fri, 7 Aug 2020 09:39:20 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 96C248D003B; Fri, 7 Aug 2020 09:39:20 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 881E98D00AC; Fri, 7 Aug 2020 09:39:20 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0184.hostedemail.com [216.40.44.184]) by kanga.kvack.org (Postfix) with ESMTP id 71E5D8D003B for ; Fri, 7 Aug 2020 09:39:20 -0400 (EDT) Received: from smtpin03.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id EC66A180AD801 for ; Fri, 7 Aug 2020 13:39:19 +0000 (UTC) X-FDA: 77123879238.03.paint27_44136ec26fc0 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin03.hostedemail.com (Postfix) with ESMTP id 7ED3428A4ED for ; Fri, 7 Aug 2020 13:39:09 +0000 (UTC) X-HE-Tag: paint27_44136ec26fc0 X-Filterd-Recvd-Size: 2707 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf42.hostedemail.com (Postfix) with ESMTP for ; Fri, 7 Aug 2020 13:39:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=eNlt5+MOMqdMiipq56av3Q5dInH/0IZEcBwwhkePOhw=; b=jooGZOBZPN+/zhWloZREEQs9Qe 1Gm0HEqpmKTnkfVygGtCjNGPDIVzbn6Oy4iJaZzm2CfGsgeL8I6RGXh+QirerafkOCyyFLowQfn04 IChcKEfRifcIOwSxygkNiijBPFeNHpOZTqM6nCUYljV7yii6nwcVfTblozH6g8PM6Q312CvbDI25M zjBglzIXAyMENEhkum19A1pCMt7D7s7lweM2Z4sd2VbM7V6c6Cd5CwISpe/CWHJm+3fcz7fTwgtvK Rlxfs1dl7r8mlxzgjjjbi+UlFk1MHOgX7V6pvrUvfVUZV9ivnPN/+OOwdWfrzlX5EzJ1coyIw+I7X K4lH3vDg==; Received: from willy by casper.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1k42aH-0003o5-B8; Fri, 07 Aug 2020 13:38:57 +0000 Date: Fri, 7 Aug 2020 14:38:57 +0100 From: Matthew Wilcox To: Shiyang Ruan Cc: linux-kernel@vger.kernel.org, linux-xfs@vger.kernel.org, linux-nvdimm@lists.01.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, darrick.wong@oracle.com, dan.j.williams@intel.com, david@fromorbit.com, hch@lst.de, rgoldwyn@suse.de, qi.fuli@fujitsu.com, y-goto@fujitsu.com Subject: Re: [RFC PATCH 0/8] fsdax: introduce FS query interface to support reflink Message-ID: <20200807133857.GC17456@casper.infradead.org> References: <20200807131336.318774-1-ruansy.fnst@cn.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200807131336.318774-1-ruansy.fnst@cn.fujitsu.com> X-Rspamd-Queue-Id: 7ED3428A4ED X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam03 X-Bogosity: Ham, tests=bogofilter, spamicity=0.001892, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Fri, Aug 07, 2020 at 09:13:28PM +0800, Shiyang Ruan wrote: > This patchset is a try to resolve the problem of tracking shared page > for fsdax. > > Instead of per-page tracking method, this patchset introduces a query > interface: get_shared_files(), which is implemented by each FS, to > obtain the owners of a shared page. It returns an owner list of this > shared page. Then, the memory-failure() iterates the list to be able > to notify each process using files that sharing this page. > > The design of the tracking method is as follow: > 1. dax_assocaite_entry() associates the owner's info to this page I think that's the first problem with this design. dax_associate_entry is a horrendous idea which needs to be ripped out, not made more important. It's all part of the general problem of trying to do something on a per-page basis instead of per-extent basis.