* Mike Travis <[EMAIL PROTECTED]> wrote: > >> +config THREAD_ORDER > >> + int "Kernel stack size (in page order)" > >> + range 1 3 > >> + depends on X86_64_SMP > >> + default "3" if X86_SMP_MAX > >> + default "1" > >> + help > >> + Increases kernel stack size. > >> + > > > > Could you please elaborate, why this is needed and put more info > > about this requirement into this patch description? > > > > People worked hard to push data allocation from stack to heap to > > make THREAD_ORDER of 0 and 1 possible. So why increase it again and > > why does this help scalability? > > > > Many thanks and Best Regards > > > > Ingo Oeser, puzzled a bit :-) > > > The primary problem arises because of cpumask_t local variables. > Until I can deal with these, increasing NR_CPUS to a really large > value increases stack size dramatically.
those should be fixed: > Here are the top stack consumers with NR_CPUS = 4k. > > 16392 isolated_cpu_setup > 10328 build_sched_domains > 8248 numa_initmem_init > 4664 cpu_attach_domain > 4104 show_shared_cpu_map > 3656 centrino_target > 3608 powernowk8_cpu_init > 3192 sched_domain_node_span > 3144 acpi_cpufreq_target > 2584 __svc_create_thread > 2568 cpu_idle_wait > 2136 netxen_nic_flash_print > 2104 powernowk8_target > 2088 _cpu_down > 2072 cache_add_dev > 2056 get_cur_freq > 0 acpi_processor_ffh_cstate_probe > 2056 microcode_write > 0 acpi_processor_get_throttling > 2048 check_supported_cpu (and most of that is performance-uncritical.) Ingo -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/