Catalin Marinas wrote: > On Mon, Sep 02, 2013 at 04:51:17PM +0100, Martin MOKREJŠ wrote: >> Catalin Marinas wrote: >>> On Mon, Sep 02, 2013 at 04:44:52PM +0100, Max Filippov wrote: >>>> On Mon, Sep 2, 2013 at 7:31 PM, Catalin Marinas <[email protected]> >>>> wrote: >>>>> On 31 August 2013 14:35, Martin MOKREJŠ <[email protected]> wrote: >>>>>> never realized that my CPUs are gone if I compile into kernel kmemleak. >>>>>> Is that really the aim? >>>>>> >>>>>> CONFIG_HAVE_DEBUG_KMEMLEAK=y >>>>>> CONFIG_DEBUG_KMEMLEAK=y >>>>>> CONFIG_DEBUG_KMEMLEAK_EARLY_LOG_SIZE=400 >>>>>> # CONFIG_DEBUG_KMEMLEAK_TEST is not set >>>>>> # CONFIG_DEBUG_KMEMLEAK_DEFAULT_OFF is not set >>>>>> >>>>>> 1. Why isn't there /sys/devices/system/cpu/cpu0/online file? >>>>>> Does not matter if it contains 0 or 1. It just should exist. >>>>> >>>>> I can't really see how kmemleak would do this, maybe other config >>>>> options that get set/cleared in the process of selecting kmemleak. Can >>>> >>>> Seems to be kmemcheck: from arch/x86/mm/kmemcheck/kmemcheck.c: >>>> >>>> int __init kmemcheck_init(void) >>>> { >>>> #ifdef CONFIG_SMP >>>> /* >>>> * Limit SMP to use a single CPU. We rely on the fact that this >>>> code >>>> * runs before SMP is set up. >>>> */ >>>> if (setup_max_cpus > 1) { >>>> printk(KERN_INFO >>>> "kmemcheck: Limiting number of CPUs to 1.\n"); >>>> setup_max_cpus = 1; >>>> } >>>> #endif >>> >>> Ah, ok, not my problem then ;) >> >> Fine, so would somebody please update the help text accessible in >> "menuconfig" >> for this entry? It should be clear that it has a huge performance impact if >> enabled. >> And, by compiling in it is enabled by default. > > Otherwise, of no-one volunteers, please feel free to send a patch ;)
No, I am not a kernel developer. Please someone else do so update the "help text". Moreover, it does not explain why /sys/devices/system/cpu/cpu0/online file is missing while /sys/devices/system/cpu/cpu[1-3]/online do exist at the same time. Thank you, Martin -- 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/
