Messages in this thread | | | Date | Sat, 07 Mar 2009 13:04:38 +0200 | From | Ozan Çağlayan <> | Subject | [RFC] A simple way to determine if the kernel needs HIGHMEM64G to be able to use all the installed memory |
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Hi,
When the installed memory size is >= 4GB, kernel drops some messages like
Warning only 4GB of memory will be used You have to enable HIGHMEM64G.
I checked that the message comes from arch/x86/init_32.c after checking max_pfn.
I'm quite dumb about the internal structures of the kernel but, wouldn't it be possible to create a simple read-only sysfs object like kexec_loaded that will contain "1" when the kernel needs HIGHMEM64G to see all of the memory and "0" when it doesn't?
I think that it would be a nice facility for distribution kernels to detect the need for a PAE enabled 32-bit kernel by just reading some /sys/.. entry.
Thanks,
--
Ozan Çağlayan <ozan_at_pardus.org.tr> -- 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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