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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 9D6F3C433DB for ; Fri, 29 Jan 2021 13:51:13 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 0528664DEB for ; Fri, 29 Jan 2021 13:51:12 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0528664DEB Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=soleen.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 0058E6B0005; Fri, 29 Jan 2021 08:51:12 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id EF7C26B0006; Fri, 29 Jan 2021 08:51:11 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id DE68B6B006C; Fri, 29 Jan 2021 08:51:11 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0222.hostedemail.com [216.40.44.222]) by kanga.kvack.org (Postfix) with ESMTP id C2AF06B0005 for ; Fri, 29 Jan 2021 08:51:11 -0500 (EST) Received: from smtpin09.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 741751EF2 for ; Fri, 29 Jan 2021 13:51:11 +0000 (UTC) X-FDA: 77758949142.09.pain73_18054d4275a8 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin09.hostedemail.com (Postfix) with ESMTP id 5BF5A180AD81F for ; Fri, 29 Jan 2021 13:51:11 +0000 (UTC) X-HE-Tag: pain73_18054d4275a8 X-Filterd-Recvd-Size: 4716 Received: from mail-ed1-f51.google.com (mail-ed1-f51.google.com [209.85.208.51]) by imf07.hostedemail.com (Postfix) with ESMTP for ; Fri, 29 Jan 2021 13:51:10 +0000 (UTC) Received: by mail-ed1-f51.google.com with SMTP id c2so10581216edr.11 for ; Fri, 29 Jan 2021 05:51:10 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=soleen.com; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=axD6Kvi4pdosXahSK458uLbtW0PLpjkq2R5FuGgzgcw=; b=iGwH4L1kdttN5AOofTRh7rIryaJWgxJcVcHmuFipKfQ5f662cZnp7U/hRY4E+OGBCi XSincTEEFAsc3rqS8ulgVi0yOZPf3/3jJYHnSiPbUAl79EI23WUdLtacsxivRQ4qbpqp M1TrjDjPmdFn1D65tJsKHkU5P3twNU2RoajJHhf1FEm3rJuUjpSAy8+YNNPSZ/s72n99 a62fyISyzy6K7z1W5FX2NgMK+Bui7epH00XFju4C4/XFmiQtkN10muUn7yXDGkkI4AsV 8hj2urk/wcVshZTjrej/ZwSAYDC7eXJu5+RmkXLFsYUpwrtFWnLPXJZLiS96R6G/uHI4 bbhg== 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=axD6Kvi4pdosXahSK458uLbtW0PLpjkq2R5FuGgzgcw=; b=sRyIfbqbL6bOY+ScCpHyQZqZaV8YvIVw6yekqhVwr2SagfKngJZf5hIb+PGGfQGAXo XeF+2UdOeAfXL0RTx6S+ICU6ApcsLdjoDpwWDVpsih0kz+P6OtwPeu2sXwC3ZmMzRFaj 4Y3/xe0If9Pysp2o4nhC/p9/xpaJPWaakTI9kULFWoGdvEVvX8zlLi7jh1MVHRehL7sV eBEOkPmNgiBWPSAdVKWel6S0ziCjwb4VsN0rWrGXOwSxFDy9Cp044pVWDge43usfALiF //1YFYrRpx2XcJ2vvnt/gJJTYuQfUq/nKTA09DgPKQ9f5qKqyRcm7BAgSJhu7PLgclB9 focA== X-Gm-Message-State: AOAM533/Tdk549gS+EMoR6LlTRjdxEzdo21AsAokBqOtdamWcjRaB8G+ QNcFzpNeZDl7pKouS+KsmMff2esULT3ztl9anGxVjg== X-Google-Smtp-Source: ABdhPJx262UUAmoa15AiyIH3ZF5OETErklqWxE9KVKw8W0aMXXYwH3ME18SurINf5D7Atq3R5vBUyuMoMrTcE73foh0= X-Received: by 2002:a05:6402:304e:: with SMTP id bu14mr5056812edb.60.1611928269679; Fri, 29 Jan 2021 05:51:09 -0800 (PST) MIME-Version: 1.0 References: <8c2b75fe-a3e5-8eff-7f37-5d23c7ad9742@redhat.com> In-Reply-To: From: Pavel Tatashin Date: Fri, 29 Jan 2021 08:50:33 -0500 Message-ID: Subject: Re: dax alignment problem on arm64 (and other achitectures) To: Dan Williams Cc: David Hildenbrand , linux-mm , LKML , Sasha Levin , Tyler Hicks , Andrew Morton , Michal Hocko , Oscar Salvador , Vlastimil Babka , Joonsoo Kim , Jason Gunthorpe , Marc Zyngier , Linux ARM , Will Deacon , James Morse , James Morris Content-Type: text/plain; charset="UTF-8" X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: > Since we last talked about this the enabling for EFI "Special Purpose" > / Soft Reserved Memory has gone upstream and instantiates device-dax > instances for address ranges marked with EFI_MEMORY_SP attribute. > Critically this way of declaring device-dax removes the consideration > of it as persistent memory and as such no metadata reservation. So, if > you are willing to maintain the metadata external to the device (which > seems reasonable for your environment) and have your platform firmware > / kernel command line mark it as EFI_CONVENTIONAL_MEMORY + > EFI_MEMORY_SP, then these reserve-free dax-devices will surface. Hi Dan, This is cool. Does it allow conversion between devdax and fsdax so DAX aware filesystem can be installed and data can be put there to be preserved across the reboot? > > See efi_fake_mem for how to apply that range to existing > EFI_CONVENTIONAL_MEMORY ranges, it requires CONFIG_EFI_SOFT_RESERVE=y. I will look at this, but because the machine on which we are using this is device-tree based it would require more changes for support. I think a new device tree node is required that would set IORESOURCE_MEM / IORES_DESC_SOFT_RESERVED properties. Thank you, Pasha > > The daxctl utility has grown mechanisms to subdivide such ranges. > > daxctl create-device > > ...starting with v71.