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@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
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