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Subject: Re: [PATCH 1/3] Add remove_memory() for ppc64
From: Dave Hansen <haveblue@us.ibm.com>
To: Badari Pulavarty <pbadari@us.ibm.com>
In-Reply-To: <1193849375.17412.34.camel@dyn9047017100.beaverton.ibm.com>
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Date: Wed, 31 Oct 2007 13:45:02 -0700
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Cc: linux-mm <linux-mm@kvack.org>, anton@au1.ibm.com, linuxppc-dev@ozlabs.org,
	Paul Mackerras <paulus@samba.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
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On Wed, 2007-10-31 at 08:49 -0800, Badari Pulavarty wrote:
> +#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);
> +	return ret;
> +}
> +EXPORT_SYMBOL_GPL(remove_memory);
> +#endif /* CONFIG_MEMORY_HOTREMOVE */

Did someone go and copy the ia64 verion?  Tsk.  Tsk.  Bad Badari.  :)

Can we just make this a weak symbol in the generic mm/memory_hotplug.c?
Or, make this the generic memory_remove() function int there and have an
arch_remove_memory() hook called from there if the architectures need to
tweak it?

-- Dave