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=-1.0 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,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 BF706C43387 for ; Sun, 6 Jan 2019 19:23:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 87B8520830 for ; Sun, 6 Jan 2019 19:23:35 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=kernel-dk.20150623.gappssmtp.com header.i=@kernel-dk.20150623.gappssmtp.com header.b="uNfkcuTR" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726050AbfAFTXe (ORCPT ); Sun, 6 Jan 2019 14:23:34 -0500 Received: from mail-pg1-f195.google.com ([209.85.215.195]:42163 "EHLO mail-pg1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726045AbfAFTXe (ORCPT ); Sun, 6 Jan 2019 14:23:34 -0500 Received: by mail-pg1-f195.google.com with SMTP id d72so19723699pga.9 for ; Sun, 06 Jan 2019 11:23:34 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20150623.gappssmtp.com; s=20150623; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=RvA0y35qCLja6k9PMYIFZ1nrlyy7oVm/17HJNaDtZL0=; b=uNfkcuTRZXqLRL2FFVOGMNQu0/ZjWBma4JDUgESlEbUMvbKiolvoKztH7lDzcYvEEX dJav0lNYJB/X9+/lHK9jQBZP9iD41keIdR3IIcZduerjQ4EImGGOwxUKoYHIi4wSmWax vSHc8pP/bod0/EguXW1ZYNXKit1DiIds30c613pbKEBjLggmbPMxGaSw3ZjvYP4GUWY0 qmfG/yeQjYJgpLtl9c6lBnoXda1kd50XQRwGu5HmxfR9DMX7YjRd/Mv5UpY+y27J8M4p HWhCUXpJhiIN2Ki4LTyUbIrPlpiMbmPc5zYlLzkSJ9MdVIOD+Ami0USW9vNcwWSbuqrp xCGg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=RvA0y35qCLja6k9PMYIFZ1nrlyy7oVm/17HJNaDtZL0=; b=nYbDye++VI9CUpwpD2fOqCF1Q5s/l4VkuD3+U/aXl/F1QId/f4u20LUIDX/3uK/bbO TRFl1Cb18TexMyrk/tvZ0Q3kdGYttyON+NslHQYAOKlA2jm6eTd4CdWQIIv7bS5n1nuh /fclHpc83VRhGIim5CZpbMYHncSMZNp9gUWV0vukOUS0GmWw1R0mpRuSefg/JHkwfiE9 W8ZYJgS4dzi8/OLnS32emuD4QUn1QNs6JXvi30Ya/1ds/4ORTlSTcMFcIHt1C6tMxox7 BW8P7jqDFyTJHfw8iAmz8F9N4L6dom8kgsBdACoybvsf/7j9U51me6fAL+Qrb2skV6M7 ffQA== X-Gm-Message-State: AJcUukc6ah3dAMMoqesFThMP1Zt4czcz6yCUzspbr05XZcb8eu/isxOR 8WFo5Z/RQoTgKPJyut8wfWWFHtmyhrpm8Q== X-Google-Smtp-Source: ALg8bN6Z3bQdETT508XuTmRJW91jjLnd9hsMxKoR4Ohv9vmgyz1UGu4AmFFLh4ZqgrlIXmiw2AbWsg== X-Received: by 2002:a63:4745:: with SMTP id w5mr8761036pgk.377.1546802613106; Sun, 06 Jan 2019 11:23:33 -0800 (PST) Received: from [192.168.1.121] (66.29.188.166.static.utbb.net. [66.29.188.166]) by smtp.gmail.com with ESMTPSA id g6sm11692127pgq.18.2019.01.06.11.23.30 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sun, 06 Jan 2019 11:23:31 -0800 (PST) Subject: Re: [PATCH] null_blk: add zoned config support information To: John Pittman , Bart Van Assche Cc: linux-block@vger.kernel.org References: <20190104154243.3538-1-jpittman@redhat.com> <1546620417.163063.45.camel@acm.org> From: Jens Axboe Message-ID: Date: Sun, 6 Jan 2019 12:23:30 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.2.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On 1/4/19 1:37 PM, John Pittman wrote: > Thanks Bart; I made the changes and sent them in as a v2, I'm sure you > already saw. I have a quick, unrelated question if you have a moment. > In testing the null_blk driver, I found that trim commands sent by fio > were rejected due to lack of support. Tracking down Shaohua's commit > 306eb6b4a ("nullb: support discard"), he mentions that "discard makes > sense for memory backed disk". Just to see what would happen, I > edited the source to make discard a configurable parameter at > modprobe, and after the edit & build, the trim commands submitted > fine. Does this sort of change make sense? I mean the ability to do > discard to null_blk without it being memory backed; solely for > testing/benchmarking purposes. I haven't found any good instructions > on creating a memory backed or discard enabled null_blk device from > the command line, so I assume a higher level driver would have to hook > in and enable these features manually. Thanks for your time and any > information. I think that would be fine, no option needed. It's really no different than reads/writes being completed without having a memory backing. -- Jens Axboe