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 E2E02C433EF for ; Thu, 26 May 2022 07:31:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345161AbiEZHa7 (ORCPT ); Thu, 26 May 2022 03:30:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41578 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234616AbiEZHa5 (ORCPT ); Thu, 26 May 2022 03:30:57 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C399D814B8; Thu, 26 May 2022 00:30:56 -0700 (PDT) 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 85FD2B81EBC; Thu, 26 May 2022 07:30:55 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D3B16C385A9; Thu, 26 May 2022 07:30:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1653550254; bh=CdhXMr2z/7slm/5lryO+Ce4aix/nGhmEL+MBV11+SLE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=lDbRqYDEvX2gmsbfB4+wc23c4CIicNZ/rXo+Ar2kvB9Q3+lziMedOlvNKHDF5A4Z+ 59ivhSGnlg07tGfKvNoEP2ZKkdYIqKTBB+mYoVBlzxKALq4e6kaxsbrc/hJusiiZuU bhuxB6cIzC7cOVrgnDF+SUar9rZ/X5e2X35V61FH+jAZIh7LbDf9KshdOfEMGSezRr C7dLqewkRPX12Ld16LIz9yGnnkmpje82McLLQz3rO4/u/LAlZTA6OeXNCy4LEHynhs LL0sgL8zPgSA4FNwITZ1nGeVv3tqR9ojB5bYV45ojlJSodRJnAzVFlFJBev7VzxMBe ZU4KOxPpZ6C1Q== Date: Thu, 26 May 2022 00:30:52 -0700 From: Eric Biggers To: Keith Busch Cc: linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org, axboe@kernel.dk, Kernel Team , hch@lst.de, bvanassche@acm.org, damien.lemoal@opensource.wdc.com, pankydev8@gmail.com, Keith Busch , Johannes Thumshirn Subject: Re: [PATCHv4 3/9] block: export dma_alignment attribute Message-ID: References: <20220526010613.4016118-1-kbusch@fb.com> <20220526010613.4016118-4-kbusch@fb.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220526010613.4016118-4-kbusch@fb.com> Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Wed, May 25, 2022 at 06:06:07PM -0700, Keith Busch wrote: > From: Keith Busch > > User space may want to know how to align their buffers to avoid > bouncing. Export the queue attribute. > > Signed-off-by: Keith Busch > Reviewed-by: Johannes Thumshirn > Reviewed-by: Christoph Hellwig > --- > Documentation/ABI/stable/sysfs-block | 9 +++++++++ > block/blk-sysfs.c | 7 +++++++ > 2 files changed, 16 insertions(+) > > diff --git a/Documentation/ABI/stable/sysfs-block b/Documentation/ABI/stable/sysfs-block > index e8797cd09aff..08f6d00df138 100644 > --- a/Documentation/ABI/stable/sysfs-block > +++ b/Documentation/ABI/stable/sysfs-block > @@ -142,6 +142,15 @@ Description: > Default value of this file is '1'(on). > > > +What: /sys/block//queue/dma_alignment > +Date: May 2022 > +Contact: linux-block@vger.kernel.org > +Description: > + Reports the alignment that user space addresses must have to be > + used for raw block device access with O_DIRECT and other driver > + specific passthrough mechanisms. > + Please keep this file in alphabetical order. - Eric