From mboxrd@z Thu Jan 1 00:00:00 1970 From: Guenter Roeck Subject: Re: linux-next: Tree for Mar 14 (mips qemu failure bisected) Date: Wed, 16 Mar 2016 19:36:41 -0700 Message-ID: <56EA1839.8010807@roeck-us.net> References: <20160314174037.0097df55@canb.auug.org.au> <20160314143729.GA31845@roeck-us.net> <20160315052659.GA9320@roeck-us.net> <56E884BA.5050103@gmail.com> <20160316001713.GA4412@roeck-us.net> <20160316132210.GA21918@roeck-us.net> <56E9C1CA.7050208@gmail.com> <56E9DB85.9090405@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <56E9DB85.9090405@gmail.com> Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org List-help: List-unsubscribe: List-software: Ecartis version 1.0.0 List-subscribe: List-owner: List-post: List-archive: To: Qais Yousef Cc: Stephen Rothwell , linux-next@vger.kernel.org, linux-kernel@vger.kernel.org, Ralf Baechle , linux-mips@linux-mips.org List-Id: linux-next.vger.kernel.org On 03/16/2016 03:17 PM, Qais Yousef wrote: > On 16/03/2016 20:27, Qais Yousef wrote: >> >> >> On 16/03/2016 13:22, Guenter Roeck wrote: >>> On Tue, Mar 15, 2016 at 05:17:13PM -0700, Guenter Roeck wrote: >>>> On Tue, Mar 15, 2016 at 09:55:06PM +0000, Qais Yousef wrote: >>>>> Hi Guenter, >>>>> >>> [ ... ] >>>>>>> Qemu test results: >>>>>>> total: 96 pass: 69 fail: 27 >>>>>>> Failed tests: >>>>>> [ ... ] >>>>>>> mips:mips_malta_smp_defconfig >>>>>> I bisected this failure to commit bb11cff327e54 ("MIPS: Make smp CMP, CPS and MT >>>>>> use the new generic IPI functions". Bisect log is attached. >>>>> Thanks for bisecting this. I tested this on a real Malta system but not >>>>> qemu. I'll try to reproduce. >>>>> >>>> I run the tests with only a single CPU core enabled. Maybe that causes >>>> problems with your code ? >>>> >>> I ran another qemu test (this time on mainline) with "-smp 2", but the only >>> difference is that the image now gets stuck even earlier. >>> >>> Also, I ran another set of bisects, this time with both mips and mips64 >>> on mainline (after your patch landed), with the same results. >>> >>> Guenter >>> >> >> OK thanks for the info. The offending commit just enables using quite a few of the newly added code before that. So the problem could be in any of the newly added code. >> >> Unfortunately I can only look at this during my limited time in the evening and I have to setup my system to compile and run this, so I won't be able to get to the bottom of this as fast as I'd like to. >> >> Qais > > OK I was up and running faster than I thought I would be. Can you confirm that you're hitting a BUG_ON() in mips_smp_ipi_init()? > > What I see is that BUG_ON() is hit because we couldn't find an ipidomain to allocate the ipis from. The reason of whih is that the qemu malta machine doesn't have a GIC though the config is compiled with GIC on. Also if I remember correctly qemu malta doesn't really support SMP. I think that was the reason I never ran this on qemu. Turns out MIPS_GIC is auto-selected by MIPS_MALTA, so I can not just unconfigure it. Too bad. That means if your patch isn't accepted, I'll have to drop the mips SMP build runtime tests, unless you have a better idea. Thanks, Guenter