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 3681DEB64DA for ; Mon, 26 Jun 2023 15:31:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230268AbjFZPbx (ORCPT ); Mon, 26 Jun 2023 11:31:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48770 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229886AbjFZPbt (ORCPT ); Mon, 26 Jun 2023 11:31:49 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A1AE41990 for ; Mon, 26 Jun 2023 08:30:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1687793445; 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=7uLYHxA1BeyjC2zeH9Gn+m3MAcFP9PjLf/sWdMqlqe8=; b=G/KdVT5TrhL0qE5EC95tWng5eO4Z9t9XunkwGBuBbZbfqzawxoI+wI5AeV9DTviB5Fgegs v7oT1oQpyMjGvEAjBrJwYY9U1osA9BfKvPYAUcn9ZXUhn6RDHz9LjrnQ1sg0NIhklXyBJJ Cfs1zfTIpz3gT+pxsbcKM8ccqIYz+oo= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-250-PqDpqqq7PE2LP5FGnG2VSA-1; Mon, 26 Jun 2023 11:30:42 -0400 X-MC-Unique: PqDpqqq7PE2LP5FGnG2VSA-1 Received: from smtp.corp.redhat.com (int-mx09.intmail.prod.int.rdu2.redhat.com [10.11.54.9]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 228B51044597; Mon, 26 Jun 2023 15:30:25 +0000 (UTC) Received: from warthog.procyon.org.uk (unknown [10.42.28.4]) by smtp.corp.redhat.com (Postfix) with ESMTP id 222FE492B01; Mon, 26 Jun 2023 15:30:23 +0000 (UTC) Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 From: David Howells In-Reply-To: References: <20230623225513.2732256-1-dhowells@redhat.com> <20230623225513.2732256-5-dhowells@redhat.com> To: Ilya Dryomov Cc: dhowells@redhat.com, netdev@vger.kernel.org, Alexander Duyck , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Willem de Bruijn , David Ahern , Matthew Wilcox , Jens Axboe , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Xiubo Li , Jeff Layton , ceph-devel@vger.kernel.org Subject: Re: [PATCH net-next v5 04/16] ceph: Use sendmsg(MSG_SPLICE_PAGES) rather than sendpage() MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-ID: <3070988.1687793422.1@warthog.procyon.org.uk> Date: Mon, 26 Jun 2023 16:30:22 +0100 Message-ID: <3070989.1687793422@warthog.procyon.org.uk> X-Scanned-By: MIMEDefang 3.1 on 10.11.54.9 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Ilya Dryomov wrote: > write_partial_message_data() is net/ceph/messenger_v1.c specific, so it > doesn't apply here. I would suggest squashing the two net/ceph patches > into one since even the titles are the same. I would, but they're now applied to net-next, so we need to patch that. > > * Write as much as possible. The socket is expected to be corked, > > - * so we don't bother with MSG_MORE/MSG_SENDPAGE_NOTLAST here. > > + * so we don't bother with MSG_MORE here. > > * > > * Return: > > - * 1 - done, nothing (else) to write > > + * >0 - done, nothing (else) to write > > It would be nice to avoid making tweaks like this to the outer > interface as part of switching to a new internal API. Ok. I'll change that and wrap the sendmsg in a loop. Though, as I asked in an earlier reply, why is MSG_DONTWAIT used here? > > + if (WARN_ON(!iov_iter_is_bvec(&con->v2.out_iter))) > > + return -EINVAL; > > Previously, this WARN_ON + error applied only to the "try sendpage" > path. There is a ton of kvec usage in net/ceph/messenger_v2.c, so I'm > pretty sure that placing it here breaks everything. This should have been removed as MSG_SPLICE_PAGES now accepts KVEC and XARRAY iterators also. Btw, is it feasible to use con->v2.out_iter_sendpage to apply MSG_SPLICE_PAGES to the iterator to be transmitted as a whole? It seems to be set depending on iterator type. David