Messages in this thread | | | Date | Fri, 5 Sep 2008 19:44:49 +0200 | From | Ingo Molnar <> | Subject | Re: [PATCH] [RESEND] x86_64: add memory hotremove config option |
| |
* Gary Hade <garyhade@us.ibm.com> wrote:
> Add memory hotremove config option to x86_64 > > Memory hotremove functionality can currently be configured into the > ia64, powerpc, and s390 kernels. This patch makes it possible to > configure the memory hotremove functionality into the x86_64 kernel as > well.
hm, why is it for 64-bit only?
> +++ linux-2.6.27-rc5/arch/x86/Kconfig 2008-09-03 13:34:55.000000000 -0700 > @@ -1384,6 +1384,9 @@ > def_bool y > depends on X86_64 || (X86_32 && HIGHMEM) > > +config ARCH_ENABLE_MEMORY_HOTREMOVE > + def_bool y
so this will break the build on 32-bit, if CONFIG_MEMORY_HOTREMOVE=y? mm/memory_hotplug.c assumes that remove_memory() is provided by the architecture.
> +#ifdef CONFIG_MEMORY_HOTREMOVE > +int remove_memory(u64 start, u64 size) > +{ > + unsigned long start_pfn, end_pfn; > + unsigned long timeout = 120 * HZ; > + int ret; > + start_pfn = start >> PAGE_SHIFT; > + end_pfn = start_pfn + (size >> PAGE_SHIFT); > + ret = offline_pages(start_pfn, end_pfn, timeout); > + if (ret) > + goto out; > + /* Arch-specific calls go here */ > +out: > + return ret; > +} > +EXPORT_SYMBOL_GPL(remove_memory); > +#endif /* CONFIG_MEMORY_HOTREMOVE */
hm, nothing appears to be arch-specific about this trivial wrapper around offline_pages().
Shouldnt this be moved to the CONFIG_MEMORY_HOTREMOVE portion of mm/memory_hotplug.c instead, as a weak function? That way architectures only have to enable ARCH_ENABLE_MEMORY_HOTREMOVE - and architectures with different/special needs can override it.
Ingo
| |