Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761004AbZFPSNg (ORCPT ); Tue, 16 Jun 2009 14:13:36 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753689AbZFPSN2 (ORCPT ); Tue, 16 Jun 2009 14:13:28 -0400 Received: from mx2.redhat.com ([66.187.237.31]:55993 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753635AbZFPSN2 (ORCPT ); Tue, 16 Jun 2009 14:13:28 -0400 Date: Tue, 16 Jun 2009 20:13:26 +0200 From: Andrea Arcangeli To: Izik Eidus Cc: linux-kernel@vger.kernel.org, Rik van Riel , Hugh Dickins , nickpiggin@yahoo.com.au Subject: Re: running get_user_pages() from kernel thread Message-ID: <20090616181325.GC23969@random.random> References: <4A37DEE7.1000208@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4A37DEE7.1000208@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 769 Lines: 14 On Tue, Jun 16, 2009 at 09:05:27PM +0300, Izik Eidus wrote: > So the question is: is this thing is by desgin? (that kernel thread cant > call get_user_pages???), should i use something like switch_mm()?? I think switch_mm trick should be used for page faults, but gup shouldn't require it because it gets the 'mm' as parameter and the current->mm has to be irrelevant. current->mm is only relevant for gup-fast (obviously :). So I think the only bit that needs fixing is grab_swap_token to not run if current->mm is null. -- 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/