From mboxrd@z Thu Jan 1 00:00:00 1970 From: Russell King - ARM Linux Subject: Re: [PATCH] ARM: Avoid discarding sections that might have SMP_ON_UP fixups Date: Fri, 11 Feb 2011 16:05:00 +0000 Message-ID: <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> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from caramon.arm.linux.org.uk ([78.32.30.218]:58269 "EHLO caramon.arm.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757380Ab1BKQFK (ORCPT ); Fri, 11 Feb 2011 11:05:10 -0500 Content-Disposition: inline In-Reply-To: Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: Dave Martin Cc: Nicolas Pitre , linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org 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 implementa= tion > >> in memory and enhancing the module loader) solved the > >> fixups-referencing-sections-discarded-from-vmlinux problem. =A0The= se > >> seem to be two separate issues. =A0I am filing to understand somet= hing? > > > > They are separate, but related issues. =A0They 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 rathe= r > > than just in kernel/spinlock.o. >=20 > 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. > If we're keeping inline spinlocks (I currently assume "yes"), then th= e > vmlinux.lds issue still needs fixing. Is that correct? However, if > we get rid of inline spinlocks we won't have the problem, though ther= e > 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. -- 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: linux@arm.linux.org.uk (Russell King - ARM Linux) Date: Fri, 11 Feb 2011 16:05:00 +0000 Subject: [PATCH] ARM: Avoid discarding sections that might have SMP_ON_UP fixups In-Reply-To: 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> Message-ID: <20110211160500.GA31529@n2100.arm.linux.org.uk> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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. > 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.