Messages in this thread Patch in this message | | | Date | Mon, 11 Aug 2008 13:36:04 -0700 | From | "Yinghai Lu" <> | Subject | Re: 2.6.27rc1 cannot boot more than 8CPUs |
| |
On Mon, Aug 11, 2008 at 1:12 PM, Yinghai Lu <yhlu.kernel@gmail.com> wrote: > On Mon, Aug 11, 2008 at 1:08 PM, Ingo Molnar <mingo@elte.hu> wrote: >> >> * Yinghai Lu <yhlu.kernel@gmail.com> wrote: >> >>> On Mon, Aug 11, 2008 at 12:59 PM, Ingo Molnar <mingo@elte.hu> wrote: >>> > >>> > * Jeff Chua <jeff.chua.linux@gmail.com> wrote: >>> > >>> >> On Wed, Aug 6, 2008 at 2:42 PM, Jeff Chua <jeff.chua.linux@gmail.com> wrote: >>> >> > On Wed, Aug 6, 2008 at 2:01 PM, Linus Torvalds >>> >> > <torvalds@linux-foundation.org> wrote: >>> >> >> One trivial thing to try would be to just bisect it. I assume 2.6.26 is >>> >> > Bisecting now. >>> >> >>> >> Thanks to all the great helpful suggestions from everyone, and this >>> >> turns out that I just need to enable the following switches, so I >>> >> didn't bisect further, and since it's first machine that I've tried >>> >> with more than 8 CPUs so I wasn't sure whether 2.6.16 has the same >>> >> problem, but if you wish, I could give 2.6.16 a try. >>> >> >>> >> > CONFIG_X86_GENERICARCH=y >>> >> > CONFIG_X86_BIGSMP=y >>> >> >>> >> Thank you all for the great linux kernel! >>> > >>> > i still consider a silent boot hang a bug we need to fix. >>> > >>> > bigsmp might be required to have all cpus available on your box, but the >>> > kernel is still supposed to transparently fall back to less CPUs (and >>> > print a warning) if it cannot do that. >>> > >>> in setup.c::setup_arch() after go over with madt or mptable >>> >>> #if defined(CONFIG_SMP) && defined(CONFIG_X86_PC) && defined(CONFIG_X86_32) >>> if (def_to_bigsmp) >>> printk(KERN_WARNING "More than 8 CPUs detected and " >>> "CONFIG_X86_PC cannot handle it.\nUse " >>> "CONFIG_X86_GENERICARCH or >>> CONFIG_X86_BIGSMP.\n"); ===> here need to change "or" to "and" >>> #endif >>> >>> or just panic here? because screen scroll to pass it, and user will >>> not notice that... >> >> a panic is better but still quite rude and doesnt give a user a system >> under which he can build an even greater kernel [after having discovered >> the warning in the syslog] ;-) >> >> best would be to use as many CPUs as we can support, and skip the rest >> and boot up fine. (and print the warning prominently - the user does not >> make maximum use of available physical resources) > > then smp start AP cpu could check the apic id >=8 etc before try to > start it.in some cases
please check attach patches..
YH [PATCH] x86: move def_to_bigsmp check later
and skil the apicid id > 8
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c index 6917779..59f07e1 100644 --- a/arch/x86/kernel/setup.c +++ b/arch/x86/kernel/setup.c @@ -863,12 +863,6 @@ void __init setup_arch(char **cmdline_p) init_apic_mappings(); ioapic_init_mappings(); -#if defined(CONFIG_SMP) && defined(CONFIG_X86_PC) && defined(CONFIG_X86_32) - if (def_to_bigsmp) - printk(KERN_WARNING "More than 8 CPUs detected and " - "CONFIG_X86_PC cannot handle it.\nUse " - "CONFIG_X86_GENERICARCH or CONFIG_X86_BIGSMP.\n"); -#endif kvm_guest_init(); e820_reserve_resources(); diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index 21821f3..ce4ee3e 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -987,7 +987,17 @@ int __cpuinit native_cpu_up(unsigned int cpu) flush_tlb_all(); low_mappings = 1; +#ifdef CONFIG_X86_PC + if (def_to_bigsmp && apicid > 8) { + printk(KERN_WARNING "More than 8 CPUs detected and " + "CONFIG_X86_PC cannot handle it.\nUse " + "CONFIG_X86_GENERICARCH and CONFIG_X86_BIGSMP.\n"); + err = -1; + } else + err = do_boot_cpu(apicid, cpu); +#else err = do_boot_cpu(apicid, cpu); +#endif zap_low_mappings(); low_mappings = 0; | |