Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756539AbcDGWxQ (ORCPT ); Thu, 7 Apr 2016 18:53:16 -0400 Received: from mx2.suse.de ([195.135.220.15]:41098 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751706AbcDGWxP (ORCPT ); Thu, 7 Apr 2016 18:53:15 -0400 Date: Fri, 8 Apr 2016 00:53:13 +0200 (CEST) From: Jiri Kosina X-X-Sender: jkosina@pobox.suse.cz To: Josh Poimboeuf cc: Jessica Yu , Miroslav Benes , linux-kernel@vger.kernel.org, live-patching@vger.kernel.org, Vojtech Pavlik Subject: Re: sched: horrible way to detect whether a task has been preempted In-Reply-To: <20160407223511.k2shbxreuxhfvot6@treble.redhat.com> Message-ID: References: <24db5a6ae5b63dfcd2096a12d18e1399a351348e.1458933243.git.jpoimboe@redhat.com> <20160407211525.GB25804@packer-debian-8-amd64.digitalocean.com> <20160407223511.k2shbxreuxhfvot6@treble.redhat.com> User-Agent: Alpine 2.00 (LNX 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 427 Lines: 15 On Thu, 7 Apr 2016, Josh Poimboeuf wrote: > To do that from C code, I guess we'd still need some arch-specific code > in an asm() statement to do the actual push? This could potentially be worked around I believe (thinking for example of a onstack-allocated local variable with predefined contents that the compiler would not be allowed to optimize out; certainly not the only option). Thanks, -- Jiri Kosina SUSE Labs