From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754098AbbDUNpR (ORCPT ); Tue, 21 Apr 2015 09:45:17 -0400 Received: from mx1.redhat.com ([209.132.183.28]:37599 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751501AbbDUNpP (ORCPT ); Tue, 21 Apr 2015 09:45:15 -0400 From: Jeff Moyer To: "kwan.huen" Cc: Matthew Wilcox , Keith Busch , Jens Axboe , Dimitri John Ledkov , linux-nvme@lists.infradead.org, linux-kernel@vger.kernel.org, linux-api@vger.kernel.org Subject: Re: [PATCH 1/2] added stream id write support References: <1429580863-3451-1-git-send-email-kwan.huen@samsung.com> <1429580863-3451-2-git-send-email-kwan.huen@samsung.com> X-PGP-KeyID: 1F78E1B4 X-PGP-CertKey: F6FE 280D 8293 F72C 65FD 5A58 1FF8 A7CA 1F78 E1B4 X-PCLoadLetter: What the f**k does that mean? Date: Tue, 21 Apr 2015 09:44:44 -0400 In-Reply-To: <1429580863-3451-2-git-send-email-kwan.huen@samsung.com> (kwan huen's message of "Mon, 20 Apr 2015 18:47:42 -0700") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.3 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org "kwan.huen" writes: > --- > drivers/block/nvme-core.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/block/nvme-core.c b/drivers/block/nvme-core.c > index 85b8036..332341a 100644 > --- a/drivers/block/nvme-core.c > +++ b/drivers/block/nvme-core.c > @@ -769,6 +769,9 @@ static int nvme_submit_iod(struct nvme_queue *nvmeq, struct nvme_iod *iod, > if (req->cmd_flags & REQ_RAHEAD) > dsmgmt |= NVME_RW_DSM_FREQ_PREFETCH; > > + if (rq_data_dir(req)) > + dsmgmt |= bio_get_streamid(req->bio) << 8; > + There's no public specification for this, yet. How many bits are set aside for the stream id? Do you need to do bounds checking/input validation? What happens on adapters with older firmware when these bits are set? Cheers, Jeff