Messages in this thread | | | Date | Wed, 17 Nov 2010 00:16:34 -0800 (PST) | From | David Rientjes <> | Subject | Re: [1/8,v3] NUMA Hotplug Emulator: add function to hide memory region via e820 table. |
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On Wed, 17 Nov 2010, shaohui.zheng@intel.com wrote:
> Index: linux-hpe4/arch/x86/kernel/e820.c > =================================================================== > --- linux-hpe4.orig/arch/x86/kernel/e820.c 2010-11-15 17:13:02.483461667 +0800 > +++ linux-hpe4/arch/x86/kernel/e820.c 2010-11-15 17:13:07.083461581 +0800 > @@ -971,6 +971,7 @@ > } > > static int userdef __initdata; > +static u64 max_mem_size __initdata = ULLONG_MAX; > > /* "mem=nopentium" disables the 4MB page tables. */ > static int __init parse_memopt(char *p) > @@ -989,12 +990,28 @@ > > userdef = 1; > mem_size = memparse(p, &p); > - e820_remove_range(mem_size, ULLONG_MAX - mem_size, E820_RAM, 1); > + e820_remove_range(mem_size, max_mem_size - mem_size, E820_RAM, 1); > + max_mem_size = mem_size; > > return 0; > }
This needs memmap= support as well, right?
> early_param("mem", parse_memopt); > > +#ifdef CONFIG_NODE_HOTPLUG_EMU > +u64 __init e820_hide_mem(u64 mem_size) > +{ > + u64 start, end_pfn; > + > + userdef = 1; > + end_pfn = e820_end_of_ram_pfn(); > + start = (end_pfn << PAGE_SHIFT) - mem_size; > + e820_remove_range(start, max_mem_size - start, E820_RAM, 1); > + max_mem_size = start; > + > + return start; > +} > +#endif
This doesn't have any sanity checking for whether e820_remove_range() will leave any significant amount of memory behind so the kernel will even boot (probably should have a guaranteed FAKE_NODE_MIN_SIZE left behind?).
> + > static int __init parse_memmap_opt(char *p) > { > char *oldp;
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