On Fri, May 24, 2013 at 05:29:19PM +0800, Tang Chen wrote:
> We mark out movable memory ranges and reserve them with MEMBLK_HOTPLUGGABLE flag in
> memblock.reserved. This should be done after the memory mapping is initialized
> because the kernel now supports allocate pagetable pages on local node, which
> are kernel pages.
>
> The reserved hotpluggable will be freed to buddy when memory initialization
> is done.
>
> And also, ensure all the nodes which the kernel resides in are un-hotpluggable.
>
> This idea is from Wen Congyang <wency@xxxxxxxxxxxxxx> and Jiang Liu <jiang.liu@xxxxxxxxxx>.
>
> Suggested-by: Jiang Liu <jiang.liu@xxxxxxxxxx>
> Suggested-by: Wen Congyang <wency@xxxxxxxxxxxxxx>
> Signed-off-by: Tang Chen <tangchen@xxxxxxxxxxxxxx>
> Reviewed-by: Vasilis Liaskovitis <vasilis.liaskovitis@xxxxxxxxxxxxxxxx>
> ---
> arch/x86/mm/numa.c | 29 +++++++++++++++++++++++++++++
> include/linux/memblock.h | 3 +++
> mm/memblock.c | 19 +++++++++++++++++++
> 3 files changed, 51 insertions(+), 0 deletions(-)
>
> diff --git a/arch/x86/mm/numa.c b/arch/x86/mm/numa.c
> index b28baf3..73f9ade 100644
> --- a/arch/x86/mm/numa.c
> +++ b/arch/x86/mm/numa.c
> @@ -727,6 +727,33 @@ static void __init early_x86_numa_init_mapping(void)
> }
> #endif
>
> +#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
> +static void __init early_mem_hotplug_init()
> +{
> + int i, nid;
> + phys_addr_t start, end;
> +
> + if (!movablecore_enable_srat)
> + return;
> +
> + for (i = 0; i < numa_meminfo.nr_blks; i++) {
> + nid = numa_meminfo.blk[i].nid;
> + start = numa_meminfo.blk[i].start;
> + end = numa_meminfo.blk[i].end;
> +
> + if (!numa_meminfo.blk[i].hotpluggable ||
> + memblock_is_kernel_node(nid))
> + continue;
In my v2 testing, I had a seabios bug: *all* memory was marked as hotpluggable
and the first if condition clause above always returned true.
I have a fixed seabios version that only sets hotplug bit to 1 for extra dimms
(see my v2 reply on how to use it with qemu):
https://github.com/vliaskov/seabios/commits/memhp-v4
I think there is another problem with mark_kernel_nodes though, see my comment
for 7/13.
thanks,
- Vasilis
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