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 E0EBEC76195 for ; Thu, 16 Mar 2023 16:25:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229735AbjCPQZp (ORCPT ); Thu, 16 Mar 2023 12:25:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54070 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229950AbjCPQZk (ORCPT ); Thu, 16 Mar 2023 12:25:40 -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 62C51974A for ; Thu, 16 Mar 2023 09:24:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1678983896; 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=P2ASxqGtebQqLOzZD8O/ATkw0sdUpI75GL+Hn4BrEXQ=; b=XWgRdlXno374dK87f4S60VmbSPd2K25HqiOEATq+onAeQrPtU46qGy++Cac9JMutmr8qg+ 7DktyWUOM1CdnKf3aIGwctHcjpme4HsJT1tVl3r0l6/o5b69L300aYUptMqnm5AmXN2WMb e+N0k5RYW6HWjHQ7IxE4V7COO7w28c0= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-590-gfY7XOqBPESOSXRoa7US_w-1; Thu, 16 Mar 2023 12:24:55 -0400 X-MC-Unique: gfY7XOqBPESOSXRoa7US_w-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.rdu2.redhat.com [10.11.54.1]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 620A93C1068F; Thu, 16 Mar 2023 16:24:54 +0000 (UTC) Received: from warthog.procyon.org.uk (unknown [10.33.36.18]) by smtp.corp.redhat.com (Postfix) with ESMTP id 076984042AC8; Thu, 16 Mar 2023 16:24:51 +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: <3DFBF27C-A62B-4AFE-87FD-3DF53FC39E8E@hammerspace.com> References: <3DFBF27C-A62B-4AFE-87FD-3DF53FC39E8E@hammerspace.com> <20230316152618.711970-1-dhowells@redhat.com> <20230316152618.711970-28-dhowells@redhat.com> To: Trond Myklebust Cc: dhowells@redhat.com, Matthew Wilcox , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Alexander Viro , Christoph Hellwig , Jens Axboe , Jeffrey Layton , Christian Brauner , Linus Torvalds , "netdev@vger.kernel.org" , "linux-fsdevel@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" , Anna Schumaker , Charles Edward Lever , "linux-nfs@vger.kernel.org" Subject: Re: [RFC PATCH 27/28] sunrpc: Use sendmsg(MSG_SPLICE_PAGES) rather then sendpage MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-ID: <754533.1678983891.1@warthog.procyon.org.uk> Date: Thu, 16 Mar 2023 16:24:51 +0000 Message-ID: <754534.1678983891@warthog.procyon.org.uk> X-Scanned-By: MIMEDefang 3.1 on 10.11.54.1 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Trond Myklebust wrote: > > + buf->bvec += 2; > > + buf->bvec[-2].bv_page = NULL; > > + buf->bvec[-1].bv_page = NULL; > > NACK. Can you elaborate? Is it that you dislike allocating extra slots for protocol bits? Or just that the bvec[] is offset by 2? Or some other reason? David