Return-Path: Received: from mail-ob0-f172.google.com ([209.85.214.172]:34208 "EHLO mail-ob0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756074AbbJHMfD (ORCPT ); Thu, 8 Oct 2015 08:35:03 -0400 Received: by obbda8 with SMTP id da8so36916682obb.1 for ; Thu, 08 Oct 2015 05:35:03 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: References: <1444240482-11287-1-git-send-email-trond.myklebust@primarydata.com> <20151007200831.GB27924@fieldses.org> Date: Thu, 8 Oct 2015 08:35:02 -0400 Message-ID: Subject: Re: [PATCH] SUNRPC: Use MSG_SENDPAGE_NOTLAST when calling sendpage() From: Trond Myklebust To: Bruce Fields Cc: Linux NFS Mailing List Content-Type: text/plain; charset=UTF-8 Sender: linux-nfs-owner@vger.kernel.org List-ID: On Wed, Oct 7, 2015 at 7:17 PM, Trond Myklebust wrote: > On Wed, Oct 7, 2015 at 4:08 PM, Bruce Fields wrote: >> On Wed, Oct 07, 2015 at 01:54:42PM -0400, Trond Myklebust wrote: >>> If we're sending more pages via kernel_sendpage(), then set >>> MSG_SENDPAGE_NOTLAST. >> >> Given that we've survived without this a while, I assume this is a hint >> that may provide better performance in some cases (have you seen that?) >> and that it doesn't have to be 100% correct? > > See the original motivation in: > > commit 2f5338442425 ("tcp: allow splice() to build full TSO packets") > > and the later bugfix (which actually introduces MSG_SENDPAGE_NOTLAST): > > commit 35f9c09fe9c7 ("tcp: tcp_sendpages() should call tcp_push() once") > >> In which case, looks fine, will queue up for 4.4.... > > Sure. It's a minor performance enhancement, so there is no immediate rush. Actually, please let me split this into 2 subpatches; one for the sunrpc server code and one for the client. It would make it easier for me if I could keep the client performance stuff in one branch.