[PATCH v2 03/12] memory-hotplug: remove redundant codes

wency
2012-10-23T10:28:57Z

From: Wen Congyang <wency@cn.fujitsu.com>

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>
---
mm/memory_hotplug.c | 101 ++++++++++++++++++++++++++++-----------------------
1 files changed, 55 insertions(+), 46 deletions(-)

diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index f4fdedd..80fc70c 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1012,20 +1012,14 @@ 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))
@@ -1042,22 +1036,61 @@ 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;
}

@@ -1075,37 +1108,13 @@ 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;
--
1.7.1