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=-7.0 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS autolearn=ham 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 9BDB9C04E53 for ; Wed, 15 May 2019 20:49:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 675432084E for ; Wed, 15 May 2019 20:49:10 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=intel-com.20150623.gappssmtp.com header.i=@intel-com.20150623.gappssmtp.com header.b="Xrsk/LtY" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727659AbfEOUtJ (ORCPT ); Wed, 15 May 2019 16:49:09 -0400 Received: from mail-oi1-f193.google.com ([209.85.167.193]:34050 "EHLO mail-oi1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726290AbfEOUtI (ORCPT ); Wed, 15 May 2019 16:49:08 -0400 Received: by mail-oi1-f193.google.com with SMTP id v10so877705oib.1 for ; Wed, 15 May 2019 13:49:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=intel-com.20150623.gappssmtp.com; s=20150623; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=e4kuu9yC2IGARpDlHp3ONWA+CXX8IcBRGF2a1wpOmUI=; b=Xrsk/LtY64WEnj9luwHstQr/vldj3FFs0v4BjRZAzdGdLcSlF9SqwRFLIkegzPHAwK 4BwtJSHQVRbiUejXql7JFlZJLxJDitd+1N9vZBZp9AH7V4H3tF8C8YrWWR2scfqIvklg K3++RgNbjyAcHvsO/gtBY9KzOiuwBdRxZ9uNTFcjGbcpIU3ySWcKBqx1i7aYED7uA8We wfFf0dayHlB1izT9baOTeQixtzK3OgVjTQ6b6HX+qmLkPmX0ef8xTCNg+LPpZh1HotLT NK2turIQ2FHb03Mu3tIJfJn8adJ/JeZmQFe6DvMuBLC9/f4qF9rSl3qlHKudtMX7ueMn BOXg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=e4kuu9yC2IGARpDlHp3ONWA+CXX8IcBRGF2a1wpOmUI=; b=V5MVelG7J1ClgFoE0aah0TTtKGwWQxriExATWDJi9irIEvXl+pOXQ4jYiyFRJA2a2S KvvGq5dvZeMSItDTGBdd1HK4W+AGbxnSlB45DYA/tVxDcY6hVGt+zK0bH15glTOQ7po1 GONhnXRBKvhYUNB1eLK4HZeAzpMWJ5UpRx2B9DW6BE7MT7ra6+EPczjAmap5c32fI1PP LDD31yBsXv1KOZLbkbSxT8f/FNbCBJnN29T2iRHFhkZ+i8RMnY90jwsid87oGA1qUWJ1 ITa3vDQHYyHip970kl43xaVbESQIBJDlmNqWA3iIfj9hYYQNV3AQyTHNXxljdf/zsyvG NWqw== X-Gm-Message-State: APjAAAX8Y1wnVhZhq3h5G/fIPgTYHCoOl6hNLEqc9euyvVxwyhrEFnkH naEvVTAwkGDLp+2UcgaRwJUWVSLIO+EB+xUHkY6gOg== X-Google-Smtp-Source: APXvYqyO6g2r/WhDKBmVOOTl4sYnhhJyyQJvRNxhfafK8+4MMPFpeaS+xqdpic/meUQecZLwA+0URassFkWkwJjqLWc= X-Received: by 2002:aca:b641:: with SMTP id g62mr5296871oif.149.1557953347952; Wed, 15 May 2019 13:49:07 -0700 (PDT) MIME-Version: 1.0 References: <20190514145422.16923-1-pagupta@redhat.com> <20190514145422.16923-5-pagupta@redhat.com> In-Reply-To: <20190514145422.16923-5-pagupta@redhat.com> From: Dan Williams Date: Wed, 15 May 2019 13:48:57 -0700 Message-ID: Subject: Re: [PATCH v9 4/7] dm: enable synchronous dax To: Mike Snitzer Cc: linux-nvdimm , Linux Kernel Mailing List , virtualization@lists.linux-foundation.org, KVM list , linux-fsdevel , Linux ACPI , Qemu Developers , linux-ext4 , linux-xfs , Ross Zwisler , Vishal L Verma , Dave Jiang , "Michael S. Tsirkin" , Jason Wang , Matthew Wilcox , "Rafael J. Wysocki" , Christoph Hellwig , Len Brown , Jan Kara , "Theodore Ts'o" , Andreas Dilger , "Darrick J. Wong" , lcapitulino@redhat.com, Kevin Wolf , Igor Mammedov , jmoyer , Nitesh Narayan Lal , Rik van Riel , Stefan Hajnoczi , Andrea Arcangeli , David Hildenbrand , david , cohuck@redhat.com, Xiao Guangrong , Paolo Bonzini , Adam Borowski , yuval shaia , jstaron@google.com, Pankaj Gupta , device-mapper development Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org [ add Mike and dm-devel ] Mike, any concerns with the below addition to the device-mapper-dax implementation? On Tue, May 14, 2019 at 7:58 AM Pankaj Gupta wrote: > > This patch sets dax device 'DAXDEV_SYNC' flag if all the target > devices of device mapper support synchrononous DAX. If device > mapper consists of both synchronous and asynchronous dax devices, > we don't set 'DAXDEV_SYNC' flag. > > Signed-off-by: Pankaj Gupta > --- > drivers/md/dm-table.c | 14 ++++++++++++++ > 1 file changed, 14 insertions(+) > > diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c > index cde3b49b2a91..1cce626ff576 100644 > --- a/drivers/md/dm-table.c > +++ b/drivers/md/dm-table.c > @@ -886,10 +886,17 @@ static int device_supports_dax(struct dm_target *ti, struct dm_dev *dev, > return bdev_dax_supported(dev->bdev, PAGE_SIZE); > } > > +static int device_synchronous(struct dm_target *ti, struct dm_dev *dev, > + sector_t start, sector_t len, void *data) > +{ > + return dax_synchronous(dev->dax_dev); > +} > + > static bool dm_table_supports_dax(struct dm_table *t) > { > struct dm_target *ti; > unsigned i; > + bool dax_sync = true; > > /* Ensure that all targets support DAX. */ > for (i = 0; i < dm_table_get_num_targets(t); i++) { > @@ -901,7 +908,14 @@ static bool dm_table_supports_dax(struct dm_table *t) > if (!ti->type->iterate_devices || > !ti->type->iterate_devices(ti, device_supports_dax, NULL)) > return false; > + > + /* Check devices support synchronous DAX */ > + if (dax_sync && > + !ti->type->iterate_devices(ti, device_synchronous, NULL)) > + dax_sync = false; > } > + if (dax_sync) > + set_dax_synchronous(t->md->dax_dev); > > return true; > } > -- > 2.20.1 >