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 X-Spam-Level: X-Spam-Status: No, score=-6.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 027F4C433ED for ; Mon, 17 May 2021 07:15:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CCAC1611C2 for ; Mon, 17 May 2021 07:15:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234784AbhEQHQ1 (ORCPT ); Mon, 17 May 2021 03:16:27 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:40708 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235153AbhEQHPt (ORCPT ); Mon, 17 May 2021 03:15:49 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1621235631; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=bLpYPqby8RHSHW0nrMHtogamAr59ozHF8RqtPLRMm6I=; b=htfysKtgVDyQc8Lf23DmTWE0KhdyiGCho7J/yfGg3jlkNI3MRncYwIzeYIg6TAd5WQeZNl 2uUX4mwP9HTjl9TwPnZDrGQ70lFLc3QZHG24TCCi4KIYK625jnF0HDNW/BzTpqRAdZ/9vX Yjn1xKNsccyregmb/l3+dSqjFgDtcTo= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-247-GwUdUN8NNF6TAbZjTQ4imw-1; Mon, 17 May 2021 03:13:49 -0400 X-MC-Unique: GwUdUN8NNF6TAbZjTQ4imw-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 3A5641007476; Mon, 17 May 2021 07:13:48 +0000 (UTC) Received: from T590 (ovpn-13-194.pek2.redhat.com [10.72.13.194]) by smtp.corp.redhat.com (Postfix) with ESMTPS id C917970591; Mon, 17 May 2021 07:13:34 +0000 (UTC) Date: Mon, 17 May 2021 15:13:29 +0800 From: Ming Lei To: JeffleXu Cc: Jens Axboe , linux-block@vger.kernel.org, Mike Snitzer , dm-devel@redhat.com, Hannes Reinecke Subject: Re: [PATCH V6 00/12] block: support bio based io polling Message-ID: References: <20210422122038.2192933-1-ming.lei@redhat.com> <630a63ef-f9e0-6ad6-d6be-ec7a46e5ec45@linux.alibaba.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <630a63ef-f9e0-6ad6-d6be-ec7a46e5ec45@linux.alibaba.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Hi JeffleXu, On Mon, May 17, 2021 at 02:16:39PM +0800, JeffleXu wrote: > Hi all, > > What's the latest progress of this bio-based polling feature? > > I've noticed that hch has also sent a patch set on this [1]. But as far > as I know, hch's patch set only refactors the interface of polling in > the block layer. It indeed helps bio-based polling for some kind of > bio-based driver, but for DM/MD where one bio could be mapped to several > split bios, more work is obviously needed, just like Lei Ming's > io_context related code in this patch set. > > hch may have better idea, after all [1] is just a preparation patch set. Yeah, we have to rebase V6 against Christoph's patchset anyway. Looks there is at least two approaches left for us: 1) keep the generic approach in V6, just rebase after Christoph's patch is finalized 2) support io polling simply in bio driver, since bio->bi_cookie is assigned for underlying bio, and it shouldn't be very difficult to support that in DM/MD. I have been thinking of it a while, but not coding it yet. BTW, all underlying bios can be linked to DM bio->bi_next, and we can add one new callback of .io_poll for polling DM/MD's bio. Thanks, Ming