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memory-hotplug: remove redundant codes

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offlining memory blocks and checking whether memory blocks are offlined
are very similar.  This patch introduces a new function to remove
redundant codes.

Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
Reviewed-by: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Jiang Liu <jiang.liu@huawei.com>
Cc: Jianguo Wu <wujianguo@huawei.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Wu Jianguo <wujianguo@huawei.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Wen Congyang 2013-02-22 16:32:54 -08:00 committed by Linus Torvalds
parent 6677e3eaf4
commit bbc76be67c
1 changed files with 82 additions and 47 deletions
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129
mm/memory_hotplug.c
View file

@ -1380,20 +1380,26 @@ 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)
/**
* walk_memory_range - walks through all mem sections in [start_pfn, end_pfn)
* @start_pfn: start pfn of the memory range
* @end_pfn: end pft of the memory range
* @arg: argument passed to func
* @func: callback for each memory section walked
*
* This function walks through all present mem sections in range
* [start_pfn, end_pfn) and call func on each mem section.
*
* Returns the return value of func.
*/
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))
@ -1410,22 +1416,76 @@ int remove_memory(u64 start, u64 size)
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;
}
/**
* offline_memory_block_cb - callback function for offlining memory block
* @mem: the memory block to be offlined
* @arg: buffer to hold error msg
*
* Always return 0, and put the error msg in arg if any.
*/
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);
/*
* When CONFIG_MEMCG is on, one memory block may be used by other
* blocks to store page cgroup when onlining pages. But we don't know
* in what order pages are onlined. So we iterate twice to offline
* memory:
* 1st iterate: offline every non primary memory block.
* 2nd iterate: offline primary (i.e. first added) memory block.
*/
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;
}
@ -1443,38 +1503,13 @@ int remove_memory(u64 start, u64 size)
* memory blocks are offlined.
*/
mem = NULL;
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;