From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nick Piggin Subject: Re: handle_mm_fault() calling convention cleanup.. Date: Mon, 6 Jul 2009 13:53:58 +0200 Message-ID: <20090706115358.GO2714@wotan.suse.de> References: <1246664107.7551.11.camel@pasglop> <1246741718.7551.22.camel@pasglop> <20090706073148.GJ2714@wotan.suse.de> <1246877776.22625.39.camel@pasglop> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <1246877776.22625.39.camel@pasglop> Sender: owner-linux-mm@kvack.org To: Benjamin Herrenschmidt Cc: Linus Torvalds , linux-arch@vger.kernel.org, Hugh Dickins , Andrew Morton , linux-mm@kvack.org, Wu Fengguang , Ingo Molnar List-Id: linux-arch.vger.kernel.org On Mon, Jul 06, 2009 at 08:56:16PM +1000, Benjamin Herrenschmidt wrote: > On Mon, 2009-07-06 at 09:31 +0200, Nick Piggin wrote: > > I have no problems with that. I'd always intended to have flags > > go further up the call chain like Linus did (since we'd discussed > > perhaps making faults interruptible and requiring an extra flag > > to distinguish get_user_pages callers that were not interruptible). > > > > So yes adding more flags to improve code or make things simpler > > is fine by me :) > > > That's before you see my evil plan of bringing the flags all the way > down to set_pte_at() :-) So long as it can be nooped out of x86 I don't see it being a problem. One problem x86 has with the mm/memory.c code is that it runs out of registers (especially in fork/exit iirc). So I wouldn't like to add unnecessary arguments to functions if they cannot be optimised away. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cantor2.suse.de ([195.135.220.15]:35797 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752343AbZGFLx4 (ORCPT ); Mon, 6 Jul 2009 07:53:56 -0400 Date: Mon, 6 Jul 2009 13:53:58 +0200 From: Nick Piggin Subject: Re: handle_mm_fault() calling convention cleanup.. Message-ID: <20090706115358.GO2714@wotan.suse.de> References: <1246664107.7551.11.camel@pasglop> <1246741718.7551.22.camel@pasglop> <20090706073148.GJ2714@wotan.suse.de> <1246877776.22625.39.camel@pasglop> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1246877776.22625.39.camel@pasglop> Sender: linux-arch-owner@vger.kernel.org List-ID: To: Benjamin Herrenschmidt Cc: Linus Torvalds , linux-arch@vger.kernel.org, Hugh Dickins , Andrew Morton , linux-mm@kvack.org, Wu Fengguang , Ingo Molnar Message-ID: <20090706115358.5qwGilO86PkzRjmd36dVtcetetnLFDWKGoWKij6wsd4@z> On Mon, Jul 06, 2009 at 08:56:16PM +1000, Benjamin Herrenschmidt wrote: > On Mon, 2009-07-06 at 09:31 +0200, Nick Piggin wrote: > > I have no problems with that. I'd always intended to have flags > > go further up the call chain like Linus did (since we'd discussed > > perhaps making faults interruptible and requiring an extra flag > > to distinguish get_user_pages callers that were not interruptible). > > > > So yes adding more flags to improve code or make things simpler > > is fine by me :) > > > That's before you see my evil plan of bringing the flags all the way > down to set_pte_at() :-) So long as it can be nooped out of x86 I don't see it being a problem. One problem x86 has with the mm/memory.c code is that it runs out of registers (especially in fork/exit iirc). So I wouldn't like to add unnecessary arguments to functions if they cannot be optimised away.