From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dave Martin Subject: Re: [PATCH] ARM: Avoid discarding sections that might have SMP_ON_UP fixups Date: Fri, 11 Feb 2011 16:17:48 +0000 Message-ID: References: <20110209142211.GA11460@n2100.arm.linux.org.uk> <20110210125624.GA3652@n2100.arm.linux.org.uk> <20110210144617.GD3652@n2100.arm.linux.org.uk> <20110210191125.GA12582@n2100.arm.linux.org.uk> <20110211101345.GA23785@n2100.arm.linux.org.uk> <20110211160500.GA31529@n2100.arm.linux.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from mail-ew0-f46.google.com ([209.85.215.46]:60920 "EHLO mail-ew0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757377Ab1BKQRu convert rfc822-to-8bit (ORCPT ); Fri, 11 Feb 2011 11:17:50 -0500 Received: by ewy5 with SMTP id 5so1432314ewy.19 for ; Fri, 11 Feb 2011 08:17:49 -0800 (PST) In-Reply-To: <20110211160500.GA31529@n2100.arm.linux.org.uk> Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: Russell King - ARM Linux Cc: Nicolas Pitre , linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org On Fri, Feb 11, 2011 at 4:05 PM, Russell King - ARM Linux wrote: > On Fri, Feb 11, 2011 at 10:52:17AM +0000, Dave Martin wrote: >> On Fri, Feb 11, 2011 at 10:13 AM, Russell King - ARM Linux >> wrote: >> > On Fri, Feb 11, 2011 at 09:33:56AM +0000, Dave Martin wrote: >> >> Agreed -- actually, I suspected we might need to support this. =A0= But I >> >> don't think solving this problem (=3D keeping the fixup implement= ation >> >> in memory and enhancing the module loader) solved the >> >> fixups-referencing-sections-discarded-from-vmlinux problem. =A0Th= ese >> >> seem to be two separate issues. =A0I am filing to understand some= thing? >> > >> > They are separate, but related issues. =A0They both ultimately hav= e the >> > same cause - the placement of the spinlock code inline rather than >> > out of line, resulting in fixups appearing all over the place rath= er >> > than just in kernel/spinlock.o. >> >> I guess what I want to understand is whether I (or someone) still >> need(s) to sort out the vmlinux.lds issue. > > Yes we do - if you build your kernel you should find that your link > fails because of discarded sections being referenced. Yep -- I'm still applying my original patch to work around that, but it sounds like I need to tidy that up. Can you elaborate on what you meant by defining a "KEEP_EXIT" macro to handle this? > >> If we're keeping inline spinlocks (I currently assume "yes"), then t= he >> vmlinux.lds issue still needs fixing. =A0Is that correct? =A0However= , if >> we get rid of inline spinlocks we won't have the problem, though the= re >> may be some performance impact -- hard to judge how significant. > > I don't see that we can get rid of inline spinlocks - it's controlled > by stuff external to the arch. That's fine -- just wanted to make sure I had the right understanding. Cheers ---Dave -- To unsubscribe from this list: send the line "unsubscribe linux-omap" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html From mboxrd@z Thu Jan 1 00:00:00 1970 From: dave.martin@linaro.org (Dave Martin) Date: Fri, 11 Feb 2011 16:17:48 +0000 Subject: [PATCH] ARM: Avoid discarding sections that might have SMP_ON_UP fixups In-Reply-To: <20110211160500.GA31529@n2100.arm.linux.org.uk> References: <20110209142211.GA11460@n2100.arm.linux.org.uk> <20110210125624.GA3652@n2100.arm.linux.org.uk> <20110210144617.GD3652@n2100.arm.linux.org.uk> <20110210191125.GA12582@n2100.arm.linux.org.uk> <20110211101345.GA23785@n2100.arm.linux.org.uk> <20110211160500.GA31529@n2100.arm.linux.org.uk> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Fri, Feb 11, 2011 at 4:05 PM, Russell King - ARM Linux wrote: > On Fri, Feb 11, 2011 at 10:52:17AM +0000, Dave Martin wrote: >> On Fri, Feb 11, 2011 at 10:13 AM, Russell King - ARM Linux >> wrote: >> > On Fri, Feb 11, 2011 at 09:33:56AM +0000, Dave Martin wrote: >> >> Agreed -- actually, I suspected we might need to support this. ?But I >> >> don't think solving this problem (= keeping the fixup implementation >> >> in memory and enhancing the module loader) solved the >> >> fixups-referencing-sections-discarded-from-vmlinux problem. ?These >> >> seem to be two separate issues. ?I am filing to understand something? >> > >> > They are separate, but related issues. ?They both ultimately have the >> > same cause - the placement of the spinlock code inline rather than >> > out of line, resulting in fixups appearing all over the place rather >> > than just in kernel/spinlock.o. >> >> I guess what I want to understand is whether I (or someone) still >> need(s) to sort out the vmlinux.lds issue. > > Yes we do - if you build your kernel you should find that your link > fails because of discarded sections being referenced. Yep -- I'm still applying my original patch to work around that, but it sounds like I need to tidy that up. Can you elaborate on what you meant by defining a "KEEP_EXIT" macro to handle this? > >> If we're keeping inline spinlocks (I currently assume "yes"), then the >> vmlinux.lds issue still needs fixing. ?Is that correct? ?However, if >> we get rid of inline spinlocks we won't have the problem, though there >> may be some performance impact -- hard to judge how significant. > > I don't see that we can get rid of inline spinlocks - it's controlled > by stuff external to the arch. That's fine -- just wanted to make sure I had the right understanding. Cheers ---Dave