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=-2.0 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 6B392C74A41 for ; Thu, 11 Jul 2019 03:09:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 43CC8214AF for ; Thu, 11 Jul 2019 03:09:03 +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="J6mQidU9" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727960AbfGKDI6 (ORCPT ); Wed, 10 Jul 2019 23:08:58 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:40430 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726353AbfGKDI6 (ORCPT ); Wed, 10 Jul 2019 23:08:58 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.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:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=kCf95klSl4II9ASRgUO/dZ/BhEcTH5foAFI3YRAMrm8=; b=J6mQidU9Nu9jXP6cFQwFeAnGJ xO6UGwej3f3LcKNTSHthSc5l6QnV9t/41sADhbPOtxwGJhusuqcizgdLeP6A0kw3iBBfdHJRpSfmH HrFk1NE5ZhA60nEQ0f9kRYvHq9qW4BMY+rJnC41EK3bl1XcDYqvjRceaeLT967PsfjjZyFP2zaJz6 JsAXd3+NxpWOEegHY72GEy27CsmwX4tUoVZUaBek+uXF7HqnCAJ/0iblm1DktLNdt2bQUMAAZXlWZ wXzYdRlP5JKjh9XlOpX3EA+YNRBDQAp0jhOLmGIXk/bqCHYDMwnqNSrVanzspV5s9nVHue31DN4lb MtQRKZtSA==; Received: from willy by bombadil.infradead.org with local (Exim 4.92 #3 (Red Hat Linux)) id 1hlPS3-0000Cr-Jj; Thu, 11 Jul 2019 03:08:55 +0000 Date: Wed, 10 Jul 2019 20:08:55 -0700 From: Matthew Wilcox To: Jan Kara Cc: Dan Williams , linux-fsdevel , Boaz Harrosh , stable , Robert Barror , Seema Pandit , linux-nvdimm , Linux Kernel Mailing List Subject: Re: [PATCH] dax: Fix missed PMD wakeups Message-ID: <20190711030855.GO32320@bombadil.infradead.org> References: <20190703195302.GJ1729@bombadil.infradead.org> <20190704032728.GK1729@bombadil.infradead.org> <20190704165450.GH31037@quack2.suse.cz> <20190704191407.GM1729@bombadil.infradead.org> <20190705191004.GC32320@bombadil.infradead.org> <20190710190204.GB14701@quack2.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190710190204.GB14701@quack2.suse.cz> User-Agent: Mutt/1.11.4 (2019-03-13) Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Wed, Jul 10, 2019 at 09:02:04PM +0200, Jan Kara wrote: > @@ -848,7 +853,7 @@ static int dax_writeback_one(struct xa_state *xas, struct dax_device *dax_dev, > if (unlikely(dax_is_locked(entry))) { > void *old_entry = entry; > > - entry = get_unlocked_entry(xas); > + entry = get_unlocked_entry(xas, 0); > > /* Entry got punched out / reallocated? */ > if (!entry || WARN_ON_ONCE(!xa_is_value(entry))) I'm not sure about this one. Are we sure there will never be a dirty PMD entry? Even if we can't create one today, it feels like a bit of a landmine to leave for someone who creates one in the future.