Re: [Patch v4 03/12] memory-hotplug: remove redundant codes

Tang Chen
2012-12-04T09:22:38Z

On 11/27/2012 06:00 PM, Wen Congyang wrote:
> offlining memory blocks and checking whether memory blocks are offlined
> are very similar. This patch introduces a new function to remove
> redundant codes.
>
> CC: David Rientjes<rientjes@google.com>
> CC: Jiang Liu<liuj97@gmail.com>
> CC: Len Brown<len.brown@intel.com>
> CC: Christoph Lameter<cl@linux.com>
> Cc: Minchan Kim<minchan.kim@gmail.com>
> CC: Andrew Morton<akpm@linux-foundation.org>
> CC: KOSAKI Motohiro<kosaki.motohiro@jp.fujitsu.com>
> CC: Yasuaki Ishimatsu<isimatu.yasuaki@jp.fujitsu.com>
> Signed-off-by: Wen Congyang<wency@cn.fujitsu.com>

Can we merge this patch with [PATCH 03/12] ?

Reviewed-by: Tang Chen <tangchen@cn.fujitsu.com>

> ---
> mm/memory_hotplug.c | 101 ++++++++++++++++++++++++++++------------------------
> 1 file changed, 55 insertions(+), 46 deletions(-)
>
> diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
> index b6d1101..6d06488 100644
> --- a/mm/memory_hotplug.c
> +++ b/mm/memory_hotplug.c
> @@ -1005,20 +1005,14 @@ int offline_pages(unsigned long start_pfn, unsigned long nr_pages)
> return __offline_pages(start_pfn, start_pfn + nr_pages, 120 * HZ);
> }
>
> -int remove_memory(u64 start, u64 size)
> +static int walk_memory_range(unsigned long start_pfn, unsigned long end_pfn,
> + void *arg, int (*func)(struct memory_block *, void *))
> {
> struct memory_block *mem = NULL;
> struct mem_section *section;
> - unsigned long start_pfn, end_pfn;
> unsigned long pfn, section_nr;
> int ret;
> - int return_on_error = 0;
> - int retry = 0;
> -
> - start_pfn = PFN_DOWN(start);
> - end_pfn = start_pfn + PFN_DOWN(size);
>
> -repeat:
> for (pfn = start_pfn; pfn< end_pfn; pfn += PAGES_PER_SECTION) {
> section_nr = pfn_to_section_nr(pfn);
> if (!present_section_nr(section_nr))
> @@ -1035,22 +1029,61 @@ repeat:
> if (!mem)
> continue;
>
> - ret = offline_memory_block(mem);
> + ret = func(mem, arg);
> if (ret) {
> - if (return_on_error) {
> - kobject_put(&mem->dev.kobj);
> - return ret;
> - } else {
> - retry = 1;
> - }
> + kobject_put(&mem->dev.kobj);
> + return ret;
> }
> }
>
> if (mem)
> kobject_put(&mem->dev.kobj);
>
> - if (retry) {
> - return_on_error = 1;
> + return 0;
> +}
> +
> +static int offline_memory_block_cb(struct memory_block *mem, void *arg)
> +{
> + int *ret = arg;
> + int error = offline_memory_block(mem);
> +
> + if (error != 0&& *ret = 0)
> + *ret = error;
> +
> + return 0;
> +}
> +
> +static int is_memblock_offlined_cb(struct memory_block *mem, void *arg)
> +{
> + int ret = !is_memblock_offlined(mem);
> +
> + if (unlikely(ret))
> + pr_warn("removing memory fails, because memory "
> + "[%#010llx-%#010llx] is onlined\n",
> + PFN_PHYS(section_nr_to_pfn(mem->start_section_nr)),
> + PFN_PHYS(section_nr_to_pfn(mem->end_section_nr + 1))-1);
> +
> + return ret;
> +}
> +
> +int remove_memory(u64 start, u64 size)
> +{
> + unsigned long start_pfn, end_pfn;
> + int ret = 0;
> + int retry = 1;
> +
> + start_pfn = PFN_DOWN(start);
> + end_pfn = start_pfn + PFN_DOWN(size);
> +
> +repeat:
> + walk_memory_range(start_pfn, end_pfn,&ret,
> + offline_memory_block_cb);
> + if (ret) {
> + if (!retry)
> + return ret;
> +
> + retry = 0;
> + ret = 0;
> goto repeat;
> }
>
> @@ -1068,37 +1101,13 @@ repeat:
> * memory blocks are offlined.
> */
>
> - for (pfn = start_pfn; pfn< end_pfn; pfn += PAGES_PER_SECTION) {
> - section_nr = pfn_to_section_nr(pfn);
> - if (!present_section_nr(section_nr))
> - continue;
> -
> - section = __nr_to_section(section_nr);
> - /* same memblock? */
> - if (mem)
> - if ((section_nr>= mem->start_section_nr)&&
> - (section_nr<= mem->end_section_nr))
> - continue;
> -
> - mem = find_memory_block_hinted(section, mem);
> - if (!mem)
> - continue;
> -
> - ret = is_memblock_offlined(mem);
> - if (!ret) {
> - pr_warn("removing memory fails, because memory "
> - "[%#010llx-%#010llx] is onlined\n",
> - PFN_PHYS(section_nr_to_pfn(mem->start_section_nr)),
> - PFN_PHYS(section_nr_to_pfn(mem->end_section_nr + 1)) - 1);
> -
> - kobject_put(&mem->dev.kobj);
> - unlock_memory_hotplug();
> - return ret;
> - }
> + ret = walk_memory_range(start_pfn, end_pfn, NULL,
> + is_memblock_offlined_cb);
> + if (ret) {
> + unlock_memory_hotplug();
> + return ret;
> }
>
> - if (mem)
> - kobject_put(&mem->dev.kobj);
> unlock_memory_hotplug();
>
> return 0;