On 08/09/2013 04:53 PM, Yinghai Lu wrote: > On Fri, Aug 9, 2013 at 4:43 PM, H. Peter Anvin <hpa@xxxxxxxxx> wrote: >> On 08/09/2013 04:39 PM, Yinghai Lu wrote: >>>>> >>>>> Also parse srat table two times looks silly. >>>> >>>> By parsing SRAT twice, I can avoid memory allocation for acpi_tables_addr >>>> in acpi_initrd_override_copy() procedure at such an early time. This memory >>>> could also be in hotpluggable area. >>> >>> You already mark kernel position to be not hot-plugged, so near the >>> kernel range should be safe to be put override acpi tables. >>> >>> also what I mean parse srat two times: >>> parse to get hotplug range, and late parse other numa info again. >>> >> >> Doing two passes over a small data structure (SRAT) would seem more >> sensible than allocating memory just to avoid that... > > for x86 there is some numa info discovery path, and there are chance > srat is wrong but still have hotplug range there, or numa finally is using other > way or not used. Inconsistency looks weird. > > numa_meminfo is static struct, we have way to get final numa info early enough > before we need use memblock to alloc buffer with it. > Now, for kernel-generated data if you can define a sensible maximum you can put it in brk, if not, you have a serious problem. -hpa -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>