From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753219AbcFOIDe (ORCPT ); Wed, 15 Jun 2016 04:03:34 -0400 Received: from mail-wm0-f50.google.com ([74.125.82.50]:35743 "EHLO mail-wm0-f50.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752003AbcFOIDb (ORCPT ); Wed, 15 Jun 2016 04:03:31 -0400 Date: Wed, 15 Jun 2016 10:03:27 +0200 From: Ingo Molnar To: Andy Lutomirski Cc: Brian Gerst , X86 ML , "linux-kernel@vger.kernel.org" , "H. Peter Anvin" , Denys Vlasenko , Borislav Petkov , Thomas Gleixner Subject: Re: [PATCH 3/4] x86: Rewrite switch_to() code Message-ID: <20160615080327.GA15894@gmail.com> References: <1463846691-18498-1-git-send-email-brgerst@gmail.com> <1463846691-18498-4-git-send-email-brgerst@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Andy Lutomirski wrote: > On Sat, May 21, 2016 at 9:04 AM, Brian Gerst wrote: > > > Move the low-level context switch code to an out-of-line asm stub instead of > > using complex inline asm. This allows constructing a new stack frame for the > > child process to make it seamlessly flow to ret_from_fork without an extra > > test and branch in __switch_to(). It also improves code generation for > > __schedule() by using the C calling convention instead of clobbering all > > registers. > > Just a heads up: I'm writing some code that conflicts with this patch. The > conflict will be easy to resolve, and, if this patch beats mine to -tip, I'll > rebase. So I was expecting another iteration of this switch_to() series, but had no fundamental objections to the concept. Thanks, Ingo