On 06/24/2017 07:52 PM, Wei Yang wrote:
> Memory hotplug unit is memory_block which contains one or several
> mem_section. The current logic is iterating on each mem_section and add or
> adjust the memory_block every time.
>
> This patch makes the __add_pages() iterate on memory_block and split
> __add_section() to two functions: __add_section() and __add_memory_block().
>
> The first one would take care of each section data and the second one would
> register the memory_block at once, which makes the function more clear and
> natural.
>
> Signed-off-by: Wei Yang <richard.weiyang@xxxxxxxxx>
> ---
> drivers/base/memory.c | 17 +++++------------
> mm/memory_hotplug.c | 27 +++++++++++++++++----------
> 2 files changed, 22 insertions(+), 22 deletions(-)
>
> diff --git a/drivers/base/memory.c b/drivers/base/memory.c
> index b54cfe9cd98b..468e5ad1bc87 100644
> --- a/drivers/base/memory.c
> +++ b/drivers/base/memory.c
> @@ -705,19 +705,12 @@ int register_new_memory(int nid, struct mem_section *section)
>
> mutex_lock(&mem_sysfs_mutex);
>
> - mem = find_memory_block(section);
> - if (mem) {
> - mem->section_count++;
> - put_device(&mem->dev);
> - } else {
> - ret = init_memory_block(&mem, section, MEM_OFFLINE);
> - if (ret)
> - goto out;
> - mem->section_count++;
> - }
> + ret = init_memory_block(&mem, section, MEM_OFFLINE);
> + if (ret)
> + goto out;
> + mem->section_count = sections_per_block;
Hi Wei,
Things have changed...the register_new_memory() routine is accepting a single section,
but instead of registering just that section, it is registering a containing block.
(That works, because apparently the approach is to make sections_per_block == 1,
and eventually kill sections, if I am reading all this correctly.)
So, how about this: let's add a line to the function comment:
* Register an entire memory_block.
That makes it clearer that we're dealing in blocks, even though the memsection*
argument is passed in.
>
> - if (mem->section_count == sections_per_block)
> - ret = register_mem_sect_under_node(mem, nid);
> + ret = register_mem_sect_under_node(mem, nid);
> out:
> mutex_unlock(&mem_sysfs_mutex);
> return ret;
> diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
> index a79a83ec965f..14a08b980b59 100644
> --- a/mm/memory_hotplug.c
> +++ b/mm/memory_hotplug.c
> @@ -302,8 +302,7 @@ void __init register_page_bootmem_info_node(struct pglist_data *pgdat)
> }
> #endif /* CONFIG_HAVE_BOOTMEM_INFO_NODE */
>
> -static int __meminit __add_section(int nid, unsigned long phys_start_pfn,
> - bool want_memblock)
> +static int __meminit __add_section(int nid, unsigned long phys_start_pfn)
> {
> int ret;
> int i;
> @@ -332,6 +331,18 @@ static int __meminit __add_section(int nid, unsigned long phys_start_pfn,
> SetPageReserved(page);
> }
>
> + return 0;
> +}
> +
> +static int __meminit __add_memory_block(int nid, unsigned long phys_start_pfn,
> + bool want_memblock)
> +{
> + int ret;
> +
> + ret = __add_section(nid, phys_start_pfn);
> + if (ret)
> + return ret;
> +
> if (!want_memblock)
> return 0;
>
> @@ -347,15 +358,10 @@ static int __meminit __add_section(int nid, unsigned long phys_start_pfn,
> int __ref __add_pages(int nid, unsigned long phys_start_pfn,
> unsigned long nr_pages, bool want_memblock)
> {
> - unsigned long i;
> + unsigned long pfn;
> int err = 0;
> - int start_sec, end_sec;
> struct vmem_altmap *altmap;
>
> - /* during initialize mem_map, align hot-added range to section */
> - start_sec = pfn_to_section_nr(phys_start_pfn);
> - end_sec = pfn_to_section_nr(phys_start_pfn + nr_pages - 1);
> -
> altmap = to_vmem_altmap((unsigned long) pfn_to_page(phys_start_pfn));
> if (altmap) {
> /*
> @@ -370,8 +376,9 @@ int __ref __add_pages(int nid, unsigned long phys_start_pfn,
> altmap->alloc = 0;
> }
>
> - for (i = start_sec; i <= end_sec; i++) {
> - err = __add_section(nid, section_nr_to_pfn(i), want_memblock);
> + for (pfn; pfn < phys_start_pfn + nr_pages;
> + pfn += sections_per_block * PAGES_PER_SECTION) {
A pages_per_block variable would be nice here, too.
thanks,
john h
> + err = __add_memory_block(nid, pfn, want_memblock);
>
> /*
> * EEXIST is finally dealt with by ioresource collision
>
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