* Nathan Fontenot (nf...@austin.ibm.com) wrote:
> Robert Jennings wrote:
>> Memory balloon drivers can allocate a large amount of memory which
>> is not movable but could be freed to accommodate memory hotplug remove.
>>
>> Prior to calling the memory hotplug notifier chain the memory in the
>> pageblock is isolated. If the migrate type is not MIGRATE_MOVABLE the
>> isolation will not proceed, causing the memory removal for that page
>> range to fail.
>>
>> Rather than immediately failing pageblock isolation if the the
>> migrateteype is not MIGRATE_MOVABLE, this patch checks if all of the
>> pages in the pageblock are owned by a registered balloon driver using a
>> notifier chain. If all of the non-movable pages are owned by a balloon,
>> they can be freed later through the memory notifier chain and the range
>> can still be isolated in set_migratetype_isolate().
>>
>> Signed-off-by: Robert Jennings <r...@linux.vnet.ibm.com>
>>
>> ---
>> drivers/base/memory.c | 19 +++++++++++++++++++
>> include/linux/memory.h | 22 ++++++++++++++++++++++
>> mm/page_alloc.c | 49
>> +++++++++++++++++++++++++++++++++++++++++--------
>> 3 files changed, 82 insertions(+), 8 deletions(-)
>>
<snip>
>> Index: b/mm/page_alloc.c
>> ===================================================================
>> --- a/mm/page_alloc.c
>> +++ b/mm/page_alloc.c
>> @@ -48,6 +48,7 @@
>> #include <linux/page_cgroup.h>
>> #include <linux/debugobjects.h>
>> #include <linux/kmemleak.h>
>> +#include <linux/memory.h>
>> #include <trace/events/kmem.h>
>> #include <asm/tlbflush.h>
>> @@ -4985,23 +4986,55 @@ void set_pageblock_flags_group(struct pa
>> int set_migratetype_isolate(struct page *page)
>> {
>> struct zone *zone;
>> - unsigned long flags;
>> + unsigned long flags, pfn, iter;
>> + long immobile = 0;
>> + struct memory_isolate_notify arg;
>> + int notifier_ret;
>> int ret = -EBUSY;
>> int zone_idx;
>> zone = page_zone(page);
>> zone_idx = zone_idx(zone);
>> +
>> + pfn = page_to_pfn(page);
>> + arg.start_addr = (unsigned long)page_address(page);
>> + arg.nr_pages = pageblock_nr_pages;
>> + arg.pages_found = 0;
>> +
>> spin_lock_irqsave(&zone->lock, flags);
>> /*
>> * In future, more migrate types will be able to be isolation target.
>> */
>> - if (get_pageblock_migratetype(page) != MIGRATE_MOVABLE &&
>> - zone_idx != ZONE_MOVABLE)
>> - goto out;
>> - set_pageblock_migratetype(page, MIGRATE_ISOLATE);
>> - move_freepages_block(zone, page, MIGRATE_ISOLATE);
>> - ret = 0;
>> -out:
>> + do {
>> + if (get_pageblock_migratetype(page) == MIGRATE_MOVABLE &&
>> + zone_idx == ZONE_MOVABLE) {
>> + ret = 0;
>> + break;
>> + }
>> +
>> + /*
>> + * If all of the pages in a zone are used by a balloon,
>> + * the range can be still be isolated. The balloon will
>> + * free these pages from the memory notifier chain.
>> + */
>> + notifier_ret = memory_isolate_notify(MEM_ISOLATE_COUNT, &arg);
>> + notifier_ret = notifier_to_errno(ret);
>
> Should this be
>
> notifier_ret = notifier_to_errno(notifier_ret);
>
> -Nathan
I'll correct this. Thanks
_______________________________________________
Linuxppc-dev mailing list
Linuxppc-dev@lists.ozlabs.org
https://lists.ozlabs.org/listinfo/linuxppc-dev
