Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752262AbbDUCcu (ORCPT ); Mon, 20 Apr 2015 22:32:50 -0400 Received: from bh-25.webhostbox.net ([208.91.199.152]:39467 "EHLO bh-25.webhostbox.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751160AbbDUCcs (ORCPT ); Mon, 20 Apr 2015 22:32:48 -0400 Message-ID: <5535B6C1.5040502@roeck-us.net> Date: Mon, 20 Apr 2015 19:32:33 -0700 From: Guenter Roeck User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.6.0 MIME-Version: 1.0 To: Michael Ellerman , David Miller CC: sowmini.varadhan@oracle.com, benh@kernel.crashing.org, aik@au1.ibm.com, anton@au1.ibm.com, paulus@samba.org, linuxppc-dev@lists.ozlabs.org, sparclinux@vger.kernel.org, linux-kernel@vger.kernel.org, schwidefsky@de.ibm.com, heiko.carstens@de.ibm.com, linux-s390@vger.kernel.org, linux390@de.ibm.com Subject: Re: sparc64: Build failure due to commit f1600e549b94 (sparc: Make sparc64 use scalable lib/iommu-common.c functions) References: <55348BE1.4010305@roeck-us.net> <20150420.122519.1661605449214047938.davem@davemloft.net> <20150420164431.GA30837@roeck-us.net> <20150420.125050.2036067807685492178.davem@davemloft.net> <1429581250.9619.6.camel@ellerman.id.au> In-Reply-To: <1429581250.9619.6.camel@ellerman.id.au> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit X-Authenticated_sender: linux@roeck-us.net X-OutGoing-Spam-Status: No, score=-1.0 X-CTCH-PVer: 0000001 X-CTCH-Spam: Unknown X-CTCH-VOD: Unknown X-CTCH-Flags: 0 X-CTCH-RefID: str=0001.0A020205.5535B6CF.00FA,ss=1,re=0.000,recu=0.000,reip=0.000,cl=1,cld=1,fgs=0 X-CTCH-Score: 0.000 X-CTCH-ScoreCust: 0.000 X-CTCH-Rules: X-CTCH-SenderID: linux@roeck-us.net X-CTCH-SenderID-Flags: 0 X-CTCH-SenderID-TotalMessages: 5 X-CTCH-SenderID-TotalSpam: 0 X-CTCH-SenderID-TotalSuspected: 0 X-CTCH-SenderID-TotalConfirmed: 0 X-CTCH-SenderID-TotalBulk: 0 X-CTCH-SenderID-TotalVirus: 0 X-CTCH-SenderID-TotalRecipients: 0 X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - bh-25.webhostbox.net X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - roeck-us.net X-Get-Message-Sender-Via: bh-25.webhostbox.net: mailgid no entry from get_relayhosts_entry X-Source: X-Source-Args: X-Source-Dir: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2747 Lines: 73 On 04/20/2015 06:54 PM, Michael Ellerman wrote: > On Mon, 2015-04-20 at 12:50 -0400, David Miller wrote: >> From: Guenter Roeck >> Date: Mon, 20 Apr 2015 09:44:31 -0700 >> >>> On Mon, Apr 20, 2015 at 12:25:19PM -0400, David Miller wrote: >>>> From: Guenter Roeck >>>> Date: Sun, 19 Apr 2015 22:17:21 -0700 >>>> >>>>> The debug option is intended for all _other_ architectures, to >>>>> ensure that changes made for those don't break alpha/s390 >>>>> builds. alpha/s390 have ARCH_NEEDS_WEAK_PER_CPU and don't need the >>>>> debug option. >>>> >>>> Ironically this would not create a build failure for the architectures >>>> where this matters, because only powerpc has the like named percpu >>>> symbol. >>>> >>>> So it's not really meeting the stated objective in this case. >>> >>> Yes, that is correct; it can only find problems in non-architecture >>> code, and on the downside produces false positives and thus build errors >>> like this one. >>> >>> Which makes the fix a bit philosophical. Rename iommu_pool_hash in >>> iommu-common, or drop DEBUG_FORCE_WEAK_PER_CPU. I would rename >>> iommu_pool_hash, but that is just me. Ultimately, I don't really >>> care one way or another, as long as the problem gets fixed. >> >> If nightly builds of s390 and alpha, the two platforms where this >> matters, are being done as reported in this thread, then I really >> don't see the value in DEBUG_FORCE_WEAK_PER_CPU. Me not either, but, as you say, that is a different discussion. > > We do an s390 allmodconfig for every linux-next release: > > http://kisskb.ellerman.id.au/kisskb/target/573/ > > And also for Linus' tree: > > http://kisskb.ellerman.id.au/kisskb/target/568/ > > We don't have alpha allmodconfig enabled, though we could, but we do build the > defconfig: > > http://kisskb.ellerman.id.au/kisskb/target/2499/ > http://kisskb.ellerman.id.au/kisskb/target/2494/ > I cover alpha:allmodconfig in my builds for -next, mainline, as well as all kernel.org stable releases and release candidates. This discussion is a good argument for enabling s390:allmodconfig as well. > So I think that should be sufficient to catch any percpus that are introduced > in generic code with the same name as s390/alpha variables. > Yes, but unfortunately only after the fact, though I don't see a means to avoid that. > >> But I guess that's a more involved longer-term discussion and I guess >> I'll apply Sowmini's patches for now. > Thanks! Guenter -- 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/