Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753918Ab0AQPnu (ORCPT ); Sun, 17 Jan 2010 10:43:50 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753239Ab0AQPnu (ORCPT ); Sun, 17 Jan 2010 10:43:50 -0500 Received: from bombadil.infradead.org ([18.85.46.34]:60033 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753230Ab0AQPnt (ORCPT ); Sun, 17 Jan 2010 10:43:49 -0500 Date: Sun, 17 Jan 2010 10:43:43 -0500 From: Christoph Hellwig To: Gleb Natapov Cc: kvm@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, avi@redhat.com, mingo@elte.hu, a.p.zijlstra@chello.nl, tglx@linutronix.de, hpa@zytor.com, riel@redhat.com, cl@linux-foundation.org Subject: Re: [PATCH v3 06/12] Add get_user_pages() variant that fails if major fault is required. Message-ID: <20100117154343.GA27123@infradead.org> References: <1262700774-1808-1-git-send-email-gleb@redhat.com> <1262700774-1808-7-git-send-email-gleb@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1262700774-1808-7-git-send-email-gleb@redhat.com> User-Agent: Mutt/1.5.19 (2009-01-05) 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 Content-Length: 1010 Lines: 28 On Tue, Jan 05, 2010 at 04:12:48PM +0200, Gleb Natapov wrote: > This patch add get_user_pages() variant that only succeeds if getting > a reference to a page doesn't require major fault. > > +int get_user_pages_noio(struct task_struct *tsk, struct mm_struct *mm, > + unsigned long start, int nr_pages, int write, int force, > + struct page **pages, struct vm_area_struct **vmas) > +{ > + int flags = FOLL_TOUCH | FOLL_MINOR; > + > + if (pages) > + flags |= FOLL_GET; > + if (write) > + flags |= FOLL_WRITE; > + if (force) > + flags |= FOLL_FORCE; > + > + return __get_user_pages(tsk, mm, start, nr_pages, flags, pages, vmas); Wouldn't it be better to just export __get_user_pages as a proper user interface, maybe replacing get_user_pages by it entirely? -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/