From patchwork Mon Feb 11 16:15:29 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Davidlohr Bueso X-Patchwork-Id: 1039937 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=stgolabs.net Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 43yrVq0WfGz9sMp for ; Tue, 12 Feb 2019 03:15:47 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729033AbfBKQPm (ORCPT ); Mon, 11 Feb 2019 11:15:42 -0500 Received: from mx2.suse.de ([195.135.220.15]:55904 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727887AbfBKQPm (ORCPT ); Mon, 11 Feb 2019 11:15:42 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 6684CAC8D; Mon, 11 Feb 2019 16:15:40 +0000 (UTC) Date: Mon, 11 Feb 2019 08:15:29 -0800 From: Davidlohr Bueso To: akpm@linux-foundation.org Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, "David S . Miller" , Bjorn Topel , Magnus Karlsson , netdev@vger.kernel.org, Davidlohr Bueso Subject: [PATCH v2] xsk: share the mmap_sem for page pinning Message-ID: <20190211161529.uskq5ca7y3j5522i@linux-r8p5> Mail-Followup-To: akpm@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, "David S . Miller" , Bjorn Topel , Magnus Karlsson , netdev@vger.kernel.org, Davidlohr Bueso References: <20190207053740.26915-1-dave@stgolabs.net> <20190207053740.26915-2-dave@stgolabs.net> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20190207053740.26915-2-dave@stgolabs.net> User-Agent: NeoMutt/20180323 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Holding mmap_sem exclusively for a gup() is an overkill. Lets share the lock and replace the gup call for gup_longterm(), as it is better suited for the lifetime of the pinning. Cc: David S. Miller Cc: Bjorn Topel Cc: Magnus Karlsson CC: netdev@vger.kernel.org Signed-off-by: Davidlohr Bueso Acked-by: Björn Töpel --- net/xdp/xdp_umem.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/net/xdp/xdp_umem.c b/net/xdp/xdp_umem.c index 5ab236c5c9a5..e7fa8d0d7090 100644 --- a/net/xdp/xdp_umem.c +++ b/net/xdp/xdp_umem.c @@ -265,10 +265,10 @@ static int xdp_umem_pin_pages(struct xdp_umem *umem) if (!umem->pgs) return -ENOMEM; - down_write(¤t->mm->mmap_sem); - npgs = get_user_pages(umem->address, umem->npgs, + down_read(¤t->mm->mmap_sem); + npgs = get_user_pages_longterm(umem->address, umem->npgs, gup_flags, &umem->pgs[0], NULL); - up_write(¤t->mm->mmap_sem); + up_read(¤t->mm->mmap_sem); if (npgs != umem->npgs) { if (npgs >= 0) {