Messages in this thread | ![/](/images/icornerl.gif) | | Date | Tue, 11 Mar 2003 03:25:12 -0500 (EST) | From | Zwane Mwaikambo <> | Subject | Re: cpu-2.5.64-1 |
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On Tue, 11 Mar 2003, Zwane Mwaikambo wrote:
> Have you had an opportunity to test this code yet? If you can't get that > large a 32bit SMP box, you could fire off some 'extra' cpus on i386 then > fail them during boot around cpu_up, making sure to put the failed cpus > somewhere in the middle of your cpu map so that not only do you get a > sparse map but some on the other side of 32.
Something crackpot ala;
The new boot process would look something like this (pseudo code as i don't know the types you use yet), just watch out for num_booting_cpus users.
/* the fake cpus we're going to fire up and fail */ cpumask_t fake_cpu_map = (1 << 13) | (1 << 14) | (1 << 15);
arch/i386/kernel/smpboot.c
smp_boot_cpus() { ... Dprintk("CPU present map: %lx\n", phys_cpu_present_map); for (bit = 0; bit < NR_CPUS; bit++) { if ((1 << bit) & fake_cpu_map)) set_bit(bit, cpu_callin_map); .... } }
do_boot_cpu() { cpu = ++cpucount; if ((1 << cpu) & fake_cpu_map) { /* you could probably stop here and set the boot error * without decrementing the cpucount */ goto skip_hardware_wakeup_bits; }
skip_hardware_wakeup_bits: return boot_error; }
Anyway coffee is wearing off and i must sleep...
Zwane -- function.linuxpower.ca - 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/
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