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 0EF39C32793 for ; Wed, 18 Jan 2023 23:02:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229626AbjARXCw (ORCPT ); Wed, 18 Jan 2023 18:02:52 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54128 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229476AbjARXCu (ORCPT ); Wed, 18 Jan 2023 18:02:50 -0500 Received: from mail-pj1-x102a.google.com (mail-pj1-x102a.google.com [IPv6:2607:f8b0:4864:20::102a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C20B818B29 for ; Wed, 18 Jan 2023 15:02:48 -0800 (PST) Received: by mail-pj1-x102a.google.com with SMTP id z1-20020a17090a66c100b00226f05b9595so133074pjl.0 for ; Wed, 18 Jan 2023 15:02:48 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20210112.gappssmtp.com; s=20210112; h=content-transfer-encoding:in-reply-to:from:references:cc:to :content-language:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=07OSw5FmIQ7xXLdCpaMJ2YrxM41emfDFK9D8MsKkq8M=; b=zq2N4WrKYZfksw4OJ5HtwizKo1VarEriJOuecPceQLTn6xFyO5y3qnCR4TnpbXg8u4 xo1XHvkvAHpi15WGwuQ7IQvMTQx1JUOyrNtgYM5H9+GXw02jL2XKSND+JMKZ0oQ3j62z EH0p418lWAsVP0OJP6UgVzus76ocox/OGzSFdqe9PjaH5UCJ0L31YLofs+AE+cuB5hj7 MAMgAGa00GPb8s7XCwSgFnZSh7ssNGe2DQcZLv17hdqY8c6Bza9qZD/9+T4zIdnrKu86 KtLZ6n3QyczTmPm44ESNP0wcYTpfxzq0Hy5t7lG/FNSQsyogC2ekIZJgsBSYMWTiqgjt yNbA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:in-reply-to:from:references:cc:to :content-language:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=07OSw5FmIQ7xXLdCpaMJ2YrxM41emfDFK9D8MsKkq8M=; b=cejzW6pByByvg/XR3L8tuXI0Ie7FA9HsOrElPwqS+a3pKUOTNlJhAx20cRSBK+hfEs Xz3JggfbqsGWbXC5B3BxGibPi1ay8cAAiW5/v9aw3EW1RhefcUG51trP0Tape7VxrnSH uabExF2sI7M8dNRixPzb82XNb4xS6ZKLxiwa0bSuLLOGBhe714jDsHkbFSHTIqG656BF X4kiXDGV6obDikT2Ouxl3Iz6d2AzMSOl57nmR6+1ENynsN1A17peoZwiJDZuaNBgPTMn Gnr5mofGR5GP8PLIgQzqiqoD0UsLb20gE1mX3jV2ELNLJNLorWGSuzyguDcFCr+7Gg+X wwXw== X-Gm-Message-State: AFqh2kq/WfTM/IRCsBOJ/WbrOA+Xk2fwCzUSLs7S4U1ELJ0c6XjajXuz efgNvANmpb6NLeB+JdzXElBn+w== X-Google-Smtp-Source: AMrXdXvDv5AwrPXgKuAokTxyziBbKpue7MJv/IAdgGNI4xoTM3/KrTc3+qwAkAsD4lO4plESqF3NGg== X-Received: by 2002:a05:6a20:e685:b0:b6:3e6e:af95 with SMTP id mz5-20020a056a20e68500b000b63e6eaf95mr1986348pzb.2.1674082968107; Wed, 18 Jan 2023 15:02:48 -0800 (PST) Received: from [192.168.1.136] ([198.8.77.157]) by smtp.gmail.com with ESMTPSA id n15-20020a170902d2cf00b00194bea457e7sm1507551plc.292.2023.01.18.15.02.46 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 18 Jan 2023 15:02:47 -0800 (PST) Message-ID: <4f308b47-e08c-efa6-6a86-965ba6761350@kernel.dk> Date: Wed, 18 Jan 2023 16:02:45 -0700 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux aarch64; rv:102.0) Gecko/20100101 Thunderbird/102.6.0 Subject: Re: [PATCH v3 1/9] block: Introduce QUEUE_FLAG_SUB_PAGE_SEGMENTS and CONFIG_BLK_SUB_PAGE_SEGMENTS Content-Language: en-US To: Bart Van Assche Cc: linux-block@vger.kernel.org, linux-scsi@vger.kernel.org, Jaegeuk Kim , Avri Altman , Adrian Hunter , Christoph Hellwig , Ming Lei , Keith Busch References: <20230118225447.2809787-1-bvanassche@acm.org> <20230118225447.2809787-2-bvanassche@acm.org> From: Jens Axboe In-Reply-To: <20230118225447.2809787-2-bvanassche@acm.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org On 1/18/23 3:54 PM, Bart Van Assche wrote: > Prepare for introducing support for segments smaller than the page size > by introducing the request queue flag QUEUE_FLAG_SUB_PAGE_SEGMENTS. > Introduce CONFIG_BLK_SUB_PAGE_SEGMENTS to prevent that performance of > block drivers that support segments >= PAGE_SIZE would be affected. > > Cc: Christoph Hellwig > Cc: Ming Lei > Cc: Keith Busch > Signed-off-by: Bart Van Assche > --- > block/Kconfig | 9 +++++++++ > include/linux/blkdev.h | 7 +++++++ > 2 files changed, 16 insertions(+) > > diff --git a/block/Kconfig b/block/Kconfig > index 5d9d9c84d516..e85061d2175b 100644 > --- a/block/Kconfig > +++ b/block/Kconfig > @@ -35,6 +35,15 @@ config BLOCK_LEGACY_AUTOLOAD > created on demand, but scripts that manually create device nodes and > then call losetup might rely on this behavior. > > +config BLK_SUB_PAGE_SEGMENTS > + bool "Support segments smaller than the page size" > + default n > + help > + Most storage controllers support DMA segments larger than the typical > + size of a virtual memory page. Some embedded controllers only support > + DMA segments smaller than the page size. Enable this option to support > + such controllers. This should not be a visible option at all, affected drivers should just select it. -- Jens Axboe