Re: [RFC PATCH v4 7/13] memory-hotplug : remove_memory calls __remove_pages
From: Yasuaki Ishimatsu
Date: Thu Jul 19 2012 - 05:30:39 EST
Hi Bob,
2012/07/19 17:32, Bob Liu wrote:
On Wed, Jul 18, 2012 at 6:12 PM, Yasuaki Ishimatsu
<isimatu.yasuaki@xxxxxxxxxxxxxx> wrote:
The patch adds __remove_pages() to remove_memory(). Then the range of
phys_start_pfn argument and nr_pages argument in __remove_pagse() may
have different zone. So zone argument is removed from __remove_pages()
and __remove_pages() caluculates zone in each section.
When CONFIG_SPARSEMEM_VMEMMAP is defined, there is no way to remove a memmap.
So __remove_section only calls unregister_memory_section().
CC: David Rientjes <rientjes@xxxxxxxxxx>
CC: Jiang Liu <liuj97@xxxxxxxxx>
CC: Len Brown <len.brown@xxxxxxxxx>
CC: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
CC: Paul Mackerras <paulus@xxxxxxxxx>
CC: Christoph Lameter <cl@xxxxxxxxx>
Cc: Minchan Kim <minchan.kim@xxxxxxxxx>
CC: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
CC: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
CC: Wen Congyang <wency@xxxxxxxxxxxxxx>
Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@xxxxxxxxxxxxxx>
---
arch/powerpc/platforms/pseries/hotplug-memory.c | 5 +----
include/linux/memory_hotplug.h | 3 +--
mm/memory_hotplug.c | 19 ++++++++++++-------
3 files changed, 14 insertions(+), 13 deletions(-)
Index: linux-3.5-rc6/mm/memory_hotplug.c
===================================================================
--- linux-3.5-rc6.orig/mm/memory_hotplug.c 2012-07-18 18:00:27.440145432 +0900
+++ linux-3.5-rc6/mm/memory_hotplug.c 2012-07-18 18:01:02.070712487 +0900
@@ -275,11 +275,14 @@ static int __meminit __add_section(int n
#ifdef CONFIG_SPARSEMEM_VMEMMAP
static int __remove_section(struct zone *zone, struct mem_section *ms)
{
- /*
- * XXX: Freeing memmap with vmemmap is not implement yet.
- * This should be removed later.
- */
- return -EBUSY;
+ int ret = -EINVAL;
+
+ if (!valid_section(ms))
+ return ret;
+
+ ret = unregister_memory_section(ms);
+
I saw a patch from Jiang Liu "mm/hotplug: free zone->pageset when a
zone becomes empty" to
free the zone->pageset and i think there may more cleanup needed when
a zone becomes empty.
We already have __add_zone() in __add_section(), what about add a
function like __remove_zone()
to do the cleanup here?
Thank you for your cooment. As you say, I think cleanup function of zone
is necessary. So I'll update it.
Thanks,
Yasuaki Ishimatsu.
+ return ret;
}
#else
static int __remove_section(struct zone *zone, struct mem_section *ms)
@@ -346,11 +349,11 @@ EXPORT_SYMBOL_GPL(__add_pages);
* sure that pages are marked reserved and zones are adjust properly by
* calling offline_pages().
*/
-int __remove_pages(struct zone *zone, unsigned long phys_start_pfn,
- unsigned long nr_pages)
+int __remove_pages(unsigned long phys_start_pfn, unsigned long nr_pages)
{
unsigned long i, ret = 0;
int sections_to_remove;
+ struct zone *zone;
/*
* We can only remove entire sections
@@ -363,6 +366,7 @@ int __remove_pages(struct zone *zone, un
sections_to_remove = nr_pages / PAGES_PER_SECTION;
for (i = 0; i < sections_to_remove; i++) {
unsigned long pfn = phys_start_pfn + i*PAGES_PER_SECTION;
+ zone = page_zone(pfn_to_page(pfn));
ret = __remove_section(zone, __pfn_to_section(pfn));
if (ret)
break;
@@ -1031,6 +1035,7 @@ int __ref remove_memory(int nid, u64 sta
/* remove memmap entry */
firmware_map_remove(start, start + size, "System RAM");
+ __remove_pages(start >> PAGE_SHIFT, size >> PAGE_SHIFT);
out:
unlock_memory_hotplug();
return ret;
Index: linux-3.5-rc6/include/linux/memory_hotplug.h
===================================================================
--- linux-3.5-rc6.orig/include/linux/memory_hotplug.h 2012-07-18 18:00:27.445145371 +0900
+++ linux-3.5-rc6/include/linux/memory_hotplug.h 2012-07-18 18:00:40.461982690 +0900
@@ -89,8 +89,7 @@ extern bool is_pageblock_removable_noloc
/* reasonably generic interface to expand the physical pages in a zone */
extern int __add_pages(int nid, struct zone *zone, unsigned long start_pfn,
unsigned long nr_pages);
-extern int __remove_pages(struct zone *zone, unsigned long start_pfn,
- unsigned long nr_pages);
+extern int __remove_pages(unsigned long start_pfn, unsigned long nr_pages);
#ifdef CONFIG_NUMA
extern int memory_add_physaddr_to_nid(u64 start);
Index: linux-3.5-rc6/arch/powerpc/platforms/pseries/hotplug-memory.c
===================================================================
--- linux-3.5-rc6.orig/arch/powerpc/platforms/pseries/hotplug-memory.c 2012-07-18 18:00:27.442145407 +0900
+++ linux-3.5-rc6/arch/powerpc/platforms/pseries/hotplug-memory.c 2012-07-18 18:00:40.470982578 +0900
@@ -76,7 +76,6 @@ unsigned long memory_block_size_bytes(vo
static int pseries_remove_memblock(unsigned long base, unsigned int memblock_size)
{
unsigned long start, start_pfn;
- struct zone *zone;
int i, ret;
int sections_to_remove;
@@ -87,8 +86,6 @@ static int pseries_remove_memblock(unsig
return 0;
}
- zone = page_zone(pfn_to_page(start_pfn));
-
/*
* Remove section mappings and sysfs entries for the
* section of the memory we are removing.
@@ -101,7 +98,7 @@ static int pseries_remove_memblock(unsig
sections_to_remove = (memblock_size >> PAGE_SHIFT) / PAGES_PER_SECTION;
for (i = 0; i < sections_to_remove; i++) {
unsigned long pfn = start_pfn + i * PAGES_PER_SECTION;
- ret = __remove_pages(zone, start_pfn, PAGES_PER_SECTION);
+ ret = __remove_pages(start_pfn, PAGES_PER_SECTION);
if (ret)
return ret;
}
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@xxxxxxxxxx For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/