From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752807AbeDUJH2 (ORCPT ); Sat, 21 Apr 2018 05:07:28 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:52980 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751816AbeDUJH0 (ORCPT ); Sat, 21 Apr 2018 05:07:26 -0400 Date: Sat, 21 Apr 2018 02:07:22 -0700 From: Christoph Hellwig To: Eric Dumazet Cc: "David S . Miller" , netdev , linux-kernel , Soheil Hassas Yeganeh , Eric Dumazet , linux-mm@kvack.org, linux-fsdevel@vger.kernel.org Subject: Re: [PATCH net-next 0/4] mm,tcp: provide mmap_hook to solve lockdep issue Message-ID: <20180421090722.GA11998@infradead.org> References: <20180420155542.122183-1-edumazet@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180420155542.122183-1-edumazet@google.com> User-Agent: Mutt/1.9.2 (2017-12-15) X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Apr 20, 2018 at 08:55:38AM -0700, Eric Dumazet wrote: > This patch series provide a new mmap_hook to fs willing to grab > a mutex before mm->mmap_sem is taken, to ensure lockdep sanity. > > This hook allows us to shorten tcp_mmap() execution time (while mmap_sem > is held), and improve multi-threading scalability. Missing CC to linu-fsdevel and linux-mm that will have to decide. We've rejected this approach multiple times before, so you better make a really good argument for it. introducing a multiplexer that overloads a single method certainly doesn't help making that case.