Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934021AbXJPQyo (ORCPT ); Tue, 16 Oct 2007 12:54:44 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1760122AbXJPQyd (ORCPT ); Tue, 16 Oct 2007 12:54:33 -0400 Received: from gateway-1237.mvista.com ([63.81.120.158]:61228 "EHLO gateway-1237.mvista.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760363AbXJPQyc (ORCPT ); Tue, 16 Oct 2007 12:54:32 -0400 Subject: Re: [RT] seqlocks: use of PICK_FUNCTION breaks kernel compile when CONFIG_GENERIC_TIME is NOT set From: Daniel Walker To: Remy Bohmer Cc: Ingo Molnar , linux-kernel@vger.kernel.org, linux-rt-users@vger.kernel.org In-Reply-To: <3efb10970710160135q31fd3982h17fa23768960186d@mail.gmail.com> References: <3efb10970710160135q31fd3982h17fa23768960186d@mail.gmail.com> Content-Type: text/plain Date: Tue, 16 Oct 2007 09:52:46 -0700 Message-Id: <1192553566.17527.114.camel@imap.mvista.com> Mime-Version: 1.0 X-Mailer: Evolution 2.10.3 (2.10.3-4.fc7) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2141 Lines: 68 On Tue, 2007-10-16 at 10:35 +0200, Remy Bohmer wrote: > Hello Daniel and Ingo, > > I use 2.6.23-rt1 and the patch of Daniel below which seems to be in > there breaks the compilation of the RT-kernel when CONFIG_GENERIC_TIME > is NOT set. > > It breaks in the do_gettimeofday(struct timeval *tv) code in the > architecture specific code > where there is a call to: seq = read_seqbegin_irqsave(&xtime_lock, flags); > The PICK_FUNCTION implementation does not return anything, so the > compile breaks here. > > I am figuring out how to solve this problem nicely, but I have not > found a nice solution yet. Attached I have put my hack to make it > compile on ARM again, but maybe one of you can do a better proposal to > fix this. Here's another fix for this. I compile tested for ARM (!GENERIC_TIME) , but I didn't boot test .. Could you boot test this patch? --- Move the read_seqbegin() call up in the chain so the value can be returned Signed-off-by: Daniel Walker --- include/linux/seqlock.h | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) Index: linux-2.6.23/include/linux/seqlock.h =================================================================== --- linux-2.6.23.orig/include/linux/seqlock.h +++ linux-2.6.23/include/linux/seqlock.h @@ -285,21 +285,20 @@ unsigned long __read_seqbegin_irqsave_ra unsigned long flags; local_irq_save(flags); - __read_seqbegin_raw(sl); return flags; } static __always_inline unsigned long __read_seqbegin_irqsave(seqlock_t *sl) { - __read_seqbegin(sl); return 0; } #define read_seqbegin_irqsave(lock, flags) \ -do { \ +({ \ flags = PICK_SEQ_OP_RET(__read_seqbegin_irqsave_raw, \ __read_seqbegin_irqsave, lock); \ -} while (0) + read_seqbegin(lock); \ +}) static __always_inline int __read_seqretry_irqrestore(seqlock_t *sl, unsigned iv, unsigned long flags) - 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/