Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758216AbYG3RKl (ORCPT ); Wed, 30 Jul 2008 13:10:41 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751532AbYG3RKd (ORCPT ); Wed, 30 Jul 2008 13:10:33 -0400 Received: from smtp4.pp.htv.fi ([213.243.153.38]:46339 "EHLO smtp4.pp.htv.fi" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751075AbYG3RKc (ORCPT ); Wed, 30 Jul 2008 13:10:32 -0400 Date: Wed, 30 Jul 2008 20:09:39 +0300 From: Adrian Bunk To: Andrew Morton Cc: Rusty Russell , lguest , linux-kernel@vger.kernel.org, Nick Piggin Subject: Re: [PATCH 1/2] Export get_user_pages_fast Message-ID: <20080730170939.GA28604@cs181140183.pp.htv.fi> References: <200807301438.55941.rusty@rustcorp.com.au> <20080730033523.0f38f7e4.akpm@linux-foundation.org> <20080730154736.GC21597@cs181140183.pp.htv.fi> <20080730100355.f1402dcf.akpm@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20080730100355.f1402dcf.akpm@linux-foundation.org> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2255 Lines: 67 On Wed, Jul 30, 2008 at 10:03:55AM -0700, Andrew Morton wrote: > On Wed, 30 Jul 2008 18:47:36 +0300 Adrian Bunk wrote: > > > On Wed, Jul 30, 2008 at 03:35:23AM -0700, Andrew Morton wrote: > > > On Wed, 30 Jul 2008 14:38:55 +1000 Rusty Russell wrote: > > > > > > > After all, it was made for lguest wasn't it? Still think it should be > > > > called get_current_pages() though. > > > > > > > > Signed-off-by: Rusty Russell > > > > --- > > > > arch/x86/mm/gup.c | 2 ++ > > > > 1 file changed, 2 insertions(+) > > > > > > > > diff -r cb465381f6d5 arch/x86/mm/gup.c > > > > --- a/arch/x86/mm/gup.c Wed Jul 30 10:18:44 2008 +1000 > > > > +++ b/arch/x86/mm/gup.c Wed Jul 30 14:22:53 2008 +1000 > > > > @@ -8,6 +8,7 @@ > > > > #include > > > > #include > > > > #include > > > > +#include > > > > > > > > #include > > > > > > > > @@ -296,3 +303,4 @@ slow_irqon: > > > > return ret; > > > > } > > > > } > > > > +EXPORT_SYMBOL_GPL(get_user_pages_fast); > > > > > > A regularly-occurring problem with an export like this is that someone > > > writes a driver and tests it on x86, then the driver explodes on an > > > architecture which didn't export the same symbol. > > > > > > So a better implementation might be to put > > > > > > #ifdef CONFIG_HAVE_GET_USER_PAGES_FAST > > > EXPORT_SYMBOL_GPL(get_user_pages_fast); > > > #endif > > > > > > into generic code somewhere. > > > > How would that help? > > It would fix the problem which I described. The export would still only be available on x86 since no other arch would define CONFIG_HAVE_GET_USER_PAGES_FAST. Or what do I miss? cu Adrian -- "Is there not promise of rain?" Ling Tan asked suddenly out of the darkness. There had been need of rain for many days. "Only a promise," Lao Er said. Pearl S. Buck - Dragon Seed -- 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/