From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752126AbbCYILY (ORCPT ); Wed, 25 Mar 2015 04:11:24 -0400 Received: from mail-lb0-f171.google.com ([209.85.217.171]:34518 "EHLO mail-lb0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750863AbbCYILT (ORCPT ); Wed, 25 Mar 2015 04:11:19 -0400 Message-ID: <55126DA2.5010004@bjorling.me> Date: Wed, 25 Mar 2015 09:11:14 +0100 From: =?windows-1252?Q?Matias_Bj=F8rling?= Organization: Paletta User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.2.0 MIME-Version: 1.0 To: Ming Lin-SSI , Jens Axboe , "linux-kernel@vger.kernel.org" , "linux-fsdevel@vger.kernel.org" Subject: Re: [PATCH 1/6] block: add support for carrying a stream ID in a bio References: <1427210823-5283-1-git-send-email-axboe@fb.com> <1427210823-5283-2-git-send-email-axboe@fb.com> <55119AAE.9030202@bjorling.me> <55119E5E.6020405@kernel.dk> <3A47B4705F6BE24CBB43C61AA73286215067DA@SSIEXCH-MB3.ssi.samsung.com> In-Reply-To: <3A47B4705F6BE24CBB43C61AA73286215067DA@SSIEXCH-MB3.ssi.samsung.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org >> Pushing it higher is not a big deal as far as the implementation goes, though >> 16 bits might be stealing a bit too much space for this. On 32-bit archs, we >> have 18 bits currently free that we can abuse. The Samsung device supports >> 16 streams. That's honestly a lot more than I would expect most devices to >> support in hardware, 16 is a lot of open erase blocks and write append points. >> Obviously the open channel effort would make that more feasible, though. > > Can we use 8 bits at least? I'll test performance with 16 streams. > Ming, can you provide an example of how streams will be managed for multiple applications? I can see how it would be efficient for a single application, but how will it be managed for multiple applications? -Matias