Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754051Ab1CJTpd (ORCPT ); Thu, 10 Mar 2011 14:45:33 -0500 Received: from hrndva-omtalb.mail.rr.com ([71.74.56.122]:47422 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753198Ab1CJTpc (ORCPT ); Thu, 10 Mar 2011 14:45:32 -0500 X-Authority-Analysis: v=1.1 cv=3uSaImBeuprzHBlOOPjkqgu+7PcxSRW0m2Aphm9Zmck= c=1 sm=0 a=UwRGqXM3h7MA:10 a=Q9fys5e9bTEA:10 a=OPBmh+XkhLl+Enan7BmTLg==:17 a=niRJQ5NdebbLZNx8V1kA:9 a=OC57vgZZZzemxGPPF5UA:7 a=c1xza0Kz4SJo0qucXvQQ4uCN5v8A:4 a=PUjeQqilurYA:10 a=OPBmh+XkhLl+Enan7BmTLg==:117 X-Cloudmark-Score: 0 X-Originating-IP: 67.242.120.143 Subject: Re: [PATCH 0/2] jump label: update for .39 From: Steven Rostedt To: David Daney Cc: Jason Baron , Mathieu Desnoyers , peterz@infradead.org, hpa@zytor.com, mingo@elte.hu, tglx@linutronix.de, andi@firstfloor.org, roland@redhat.com, rth@redhat.com, masami.hiramatsu.pt@hitachi.com, fweisbec@gmail.com, avi@redhat.com, davem@davemloft.net, sam@ravnborg.org, michael@ellerman.id.au, linux-kernel@vger.kernel.org, Ralf Baechle In-Reply-To: <1299785143.15854.407.camel@gandalf.stny.rr.com> References: <1299728191.15854.319.camel@gandalf.stny.rr.com> <1299771504.15854.347.camel@gandalf.stny.rr.com> <4D790A13.4060705@caviumnetworks.com> <1299780241.15854.393.camel@gandalf.stny.rr.com> <20110310182000.GB2906@redhat.com> <1299782143.15854.402.camel@gandalf.stny.rr.com> <4D791CAA.7090108@caviumnetworks.com> <1299783236.15854.405.camel@gandalf.stny.rr.com> <4D791F31.6040100@caviumnetworks.com> <1299785143.15854.407.camel@gandalf.stny.rr.com> Content-Type: text/plain; charset="ISO-8859-15" Date: Thu, 10 Mar 2011 14:45:29 -0500 Message-ID: <1299786329.15854.409.camel@gandalf.stny.rr.com> Mime-Version: 1.0 X-Mailer: Evolution 2.30.3 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1779 Lines: 39 On Thu, 2011-03-10 at 14:25 -0500, Steven Rostedt wrote: > On Thu, 2011-03-10 at 10:57 -0800, David Daney wrote: > > On 03/10/2011 10:53 AM, Steven Rostedt wrote: > > > On Thu, 2011-03-10 at 10:47 -0800, David Daney wrote: > > > > > >> The alignment requested by the assembler will have to satisfy *all* the > > >> requested alignments, so manually forcing everything to .align 8 (or > > >> .align 4 for 32-bit) should ensure that the linker doesn't put in any holes. > > > > > > I would agree with the assessment although, I don't know that it is > > > documented anywhere that this is what happens. As the previous "bug" > > > with the trace_events was solved by me adding .align(4) everywhere, I > > > would think that .align(sizeof(long)) would work here too. > > > > > > It may be a good ideal to force this alignment, and not add wasted > > > space. If anything, if this (hypothetical) bug appears, it will most > > > likely show up as a crash on boot up. I'm not too concerned about it. > > > > > > > If the linker put in gratuitous holes, things like __ex_table would > > break too. > > Again, as I have said (although I said extable not __ex_table), there > seems to be no problem when the data is of a power of 2 as well. As > __ex_table size is a power of 2. We just don't know if the linker will > add holes when the size is something other than power of 2. Anyway, I think the best thing for now is to have Jason add the .align(sizeof(long)) in the inline assembly for all locations and be done with it. -- Steve -- 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/