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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7DD22C05027 for ; Fri, 10 Feb 2023 17:31:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231889AbjBJRbb (ORCPT ); Fri, 10 Feb 2023 12:31:31 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40564 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232651AbjBJRba (ORCPT ); Fri, 10 Feb 2023 12:31:30 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 61CB5749A4 for ; Fri, 10 Feb 2023 09:31:27 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 01874B82566 for ; Fri, 10 Feb 2023 17:31:26 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3309CC433EF; Fri, 10 Feb 2023 17:31:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1676050284; bh=WB+lOUwaN4TxOtkZMvG2z8V1aYW2cANatrHZg2YPpsY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=smuYS04S4o1i+s7e6/cSsnHvZSmFgukN9dezKsr3SIprMwnz6uXD4jEt6BmFEecJd 7EbNrCHcRiZPMPmmWw5Eq8owS2BU6yYLvY0gq0nnAUDTvSbLFKKs/yJJelAMyBzJFZ QjLX/HPRVjq25AQKpvgIVYTA6U4wludETffSd6FFGAoh3I+Wx10GYertzlH9YoUM68 h3FQ/FXHjFWxSygCYNzN8rGMwZalutk+mOEmYGbkLuVFr3+ebDzFNHoHyD3aXY7I9P PfkH82A9hwYN6iRK2B0gVkIIVO0YMnkFq/gqCj06hzK3j9zxQau1pRa7z2CzjjlL8j WjESZ2P0NqJmg== Date: Fri, 10 Feb 2023 10:31:19 -0700 From: Keith Busch To: Klaus Jensen Cc: Keith Busch , fio@vger.kernel.org, axboe@kernel.dk, damien.lemoal@opensource.wdc.com, vincentfu@gmail.com, Ankit Kumar Subject: Re: [PATCHv2] fio: add fdp support for io_uring_cmd nvme engine Message-ID: References: <20230209171236.1113887-1-kbusch@meta.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: fio@vger.kernel.org On Fri, Feb 10, 2023 at 09:16:29AM +0100, Klaus Jensen wrote: > On Feb 9 09:12, Keith Busch wrote: > > From: Keith Busch > > > > Add support for NVMe TP4146 Flexible Data Placemen, allowing placement > > identifiers in write commands. The user can enabled this with the new > > "fdp=1" parameter for fio's io_uring_cmd ioengine. By default, the fio > > jobs will cycle through all the namespace's available placement > > identifiers for write commands. > > Technically, the namespace has Placement *Handles* associated and when > writing, a Placement *Identifier* is used to also specify the Reclaim > Group. Yep. The details can get a bit confusing, but the placement id is really all fio needs to construct the write command. > > The user can limit which placement > > identifiers can be used with additional parameter, "fdp_plis=", > > which can be used to separate write intensive jobs from less intensive > > ones. > > With the above in mind, it might make sense to align with the spec and > call this "fdp_pids" instead. In this implementation, you're just specifying the indices from which to pull the pids rather than providing a direct list of them, so didn't want to call it "pids". > As far as I can tell, fio won't cycle through reclaim groups and create the > pid on its own, without fdp_plis explicitly indicating it? If you don't specify any, fio will use all the placement identifiers. The code handling that in this patch is bit subtle.