linux-kernel - Re: 2.6.27rc1 cannot boot more than 8CPUs

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <86802c440808131046s4df84ba9va12d45897cf6affa@mail.gmail.com>
Date:	Wed, 13 Aug 2008 10:46:43 -0700
From:	"Yinghai Lu" <yhlu.kernel@...il.com>
To:	"Ingo Molnar" <mingo@...e.hu>
Cc:	"Jeff Chua" <jeff.chua.linux@...il.com>,
	"David Miller" <davem@...emloft.net>,
	"Linux Kernel" <linux-kernel@...r.kernel.org>
Subject: Re: 2.6.27rc1 cannot boot more than 8CPUs

On Wed, Aug 13, 2008 at 10:39 AM, Ingo Molnar <mingo@...e.hu> wrote:
>
> * Jeff Chua <jeff.chua.linux@...il.com> wrote:
>
>> On Thu, Aug 14, 2008 at 1:10 AM, Jeff Chua <jeff.chua.linux@...il.com> wrote:
>> > On Wed, Aug 13, 2008 at 10:16 PM, Ingo Molnar <mingo@...e.hu> wrote:
>> >
>> >> btw., could you please check that v2.6.27-rc3 (or later) kernels boot
>> >> fine (with about 8 cpus) even if you have genericarch/bigsmp disabled,
>> >> and do not silently hang as it happened on your box before?
>> >
>> > With 16 CPUs, it still hangs, but now the console is showing the
>> > errors as intended.
>> > ... but it is supposed to hang?
>>
>> I tried with just CONFIG_NR_CPUS=8 and this time it booted, but stange
>> thing is I only see 2 CPUs! To be more precise, it's without both
>> CONFIG_X86_GENERICARCH and CONFIG_X86_BIGSMP.
>>
>> And when I tried to enable the CPUs, it complained about:
>>
>> # cat cpu6/online
>> 0
>> # echo 1 > cpu6/online
>> More than 8 CPUs detected - skipping them.
>> Use CONFIG_X86_GENERICARCH and CONFIG_X86_BIGSMP.
>> -bash: echo: write error: Input/output error
>>
>> Prior to the patch, the system booted with all 8 CPUs.

that is new regression...

>>
>> Again, if I enable both CONFIG_X86_GENERICARCH and CONFIG_X86_BIGSMP,
>> I get all 16 CPUs.
>
> Yinghai, could the APIC ID enumeration be nonsequential and we skip CPUs
> starting at the third one already? I think we should accept all CPUs
> that are within our support range.

will try to clear those bits on smp_sanity_check...

YH
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/