On 06/24/2017 07:52 PM, Wei Yang wrote:
> The second parameter of init_memory_block() is to calculate the
> start_section_nr for the memory_block. While current implementation dose
> some unnecessary transform between mem_sectioni and section_nr.
Hi Wei,
I am unable to find anything wrong with this patch (except of course
that your top-level description in the "[PATCH 0/4" thread will need
to be added somewhere).
Here's a slight typo/grammar improvement for the patch
description above, if you like:
"The current implementation does some unnecessary conversions
between mem_section and section_nr."
thanks,
john h
>
> This patch simplifies the function by just passing the start_section_nr to
> it. By doing so, we can also simplify add_memory_block() too.
>
> Signed-off-by: Wei Yang <richard.weiyang@xxxxxxxxx>
> ---
> drivers/base/memory.c | 16 ++++++----------
> include/linux/memory.h | 2 +-
> mm/memory_hotplug.c | 2 +-
> 3 files changed, 8 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/base/memory.c b/drivers/base/memory.c
> index 468e5ad1bc87..43783dbb1d5e 100644
> --- a/drivers/base/memory.c
> +++ b/drivers/base/memory.c
> @@ -645,7 +645,7 @@ int register_memory(struct memory_block *memory)
> }
>
> static int init_memory_block(struct memory_block **memory,
> - struct mem_section *section, unsigned long state)
> + int start_section_nr, unsigned long state)
> {
> struct memory_block *mem;
> unsigned long start_pfn;
> @@ -656,9 +656,7 @@ static int init_memory_block(struct memory_block **memory,
> if (!mem)
> return -ENOMEM;
>
> - scn_nr = __section_nr(section);
> - mem->start_section_nr =
> - base_memory_block_id(scn_nr) * sections_per_block;
> + mem->start_section_nr = start_section_nr;
> mem->end_section_nr = mem->start_section_nr + sections_per_block - 1;
> mem->state = state;
> start_pfn = section_nr_to_pfn(mem->start_section_nr);
> @@ -673,21 +671,19 @@ static int init_memory_block(struct memory_block **memory,
> static int add_memory_block(int base_section_nr)
> {
> struct memory_block *mem;
> - int i, ret, section_count = 0, section_nr;
> + int i, ret, section_count = 0;
>
> for (i = base_section_nr;
> (i < base_section_nr + sections_per_block) && i < NR_MEM_SECTIONS;
> i++) {
> if (!present_section_nr(i))
> continue;
> - if (section_count == 0)
> - section_nr = i;
> section_count++;
> }
>
> if (section_count == 0)
> return 0;
> - ret = init_memory_block(&mem, __nr_to_section(section_nr), MEM_ONLINE);
> + ret = init_memory_block(&mem, base_section_nr, MEM_ONLINE);
> if (ret)
> return ret;
> mem->section_count = section_count;
> @@ -698,14 +694,14 @@ static int add_memory_block(int base_section_nr)
> * need an interface for the VM to add new memory regions,
> * but without onlining it.
> */
> -int register_new_memory(int nid, struct mem_section *section)
> +int register_new_memory(int nid, int start_section_nr)
> {
> int ret = 0;
> struct memory_block *mem;
>
> mutex_lock(&mem_sysfs_mutex);
>
> - ret = init_memory_block(&mem, section, MEM_OFFLINE);
> + ret = init_memory_block(&mem, start_section_nr, MEM_OFFLINE);
> if (ret)
> goto out;
> mem->section_count = sections_per_block;
> diff --git a/include/linux/memory.h b/include/linux/memory.h
> index 51a6355aa56d..0cbde14f7cea 100644
> --- a/include/linux/memory.h
> +++ b/include/linux/memory.h
> @@ -108,7 +108,7 @@ extern int register_memory_notifier(struct notifier_block *nb);
> extern void unregister_memory_notifier(struct notifier_block *nb);
> extern int register_memory_isolate_notifier(struct notifier_block *nb);
> extern void unregister_memory_isolate_notifier(struct notifier_block *nb);
> -extern int register_new_memory(int, struct mem_section *);
> +extern int register_new_memory(int, int);
> #ifdef CONFIG_MEMORY_HOTREMOVE
> extern int unregister_memory_section(struct mem_section *);
> #endif
> diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
> index 14a08b980b59..fc198847dd5b 100644
> --- a/mm/memory_hotplug.c
> +++ b/mm/memory_hotplug.c
> @@ -346,7 +346,7 @@ static int __meminit __add_memory_block(int nid, unsigned long phys_start_pfn,
> if (!want_memblock)
> return 0;
>
> - return register_new_memory(nid, __pfn_to_section(phys_start_pfn));
> + return register_new_memory(nid, pfn_to_section_nr(phys_start_pfn));
> }
>
> /*
>
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