Commit 7b78d335 authored by Yasunori Goto's avatar Yasunori Goto Committed by Linus Torvalds
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memory hotplug: rearrange memory hotplug notifier



Current memory notifier has some defects yet.  (Fortunately, nothing uses
it.) This patch is to fix and rearrange for them.

  - Add information of start_pfn, nr_pages, and node id if node status is
    changes from/to memoryless node for callback functions.
    Callbacks can't do anything without those information.
  - Add notification going-online status.
    It is necessary for creating per node structure before the node's
    pages are available.
  - Move GOING_OFFLINE status notification after page isolation.
    It is good place for return memory like cache for callback,
    because returned page is not used again.
  - Make CANCEL events for rollingback when error occurs.
  - Delete MEM_MAPPING_INVALID notification. It will be not used.
  - Fix compile error of (un)register_memory_notifier().
Signed-off-by: default avatarYasunori Goto <y-goto@jp.fujitsu.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 10020ca2
......@@ -137,7 +137,7 @@ static ssize_t show_mem_state(struct sys_device *dev, char *buf)
return len;
}
static inline int memory_notify(unsigned long val, void *v)
int memory_notify(unsigned long val, void *v)
{
return blocking_notifier_call_chain(&memory_chain, val, v);
}
......@@ -183,7 +183,6 @@ memory_block_action(struct memory_block *mem, unsigned long action)
break;
case MEM_OFFLINE:
mem->state = MEM_GOING_OFFLINE;
memory_notify(MEM_GOING_OFFLINE, NULL);
start_paddr = page_to_pfn(first_page) << PAGE_SHIFT;
ret = remove_memory(start_paddr,
PAGES_PER_SECTION << PAGE_SHIFT);
......@@ -191,7 +190,6 @@ memory_block_action(struct memory_block *mem, unsigned long action)
mem->state = old_state;
break;
}
memory_notify(MEM_MAPPING_INVALID, NULL);
break;
default:
printk(KERN_WARNING "%s(%p, %ld) unknown action: %ld\n",
......@@ -199,11 +197,6 @@ memory_block_action(struct memory_block *mem, unsigned long action)
WARN_ON(1);
ret = -EINVAL;
}
/*
* For now, only notify on successful memory operations
*/
if (!ret)
memory_notify(action, NULL);
return ret;
}
......
......@@ -41,18 +41,15 @@ struct memory_block {
#define MEM_ONLINE (1<<0) /* exposed to userspace */
#define MEM_GOING_OFFLINE (1<<1) /* exposed to userspace */
#define MEM_OFFLINE (1<<2) /* exposed to userspace */
#define MEM_GOING_ONLINE (1<<3)
#define MEM_CANCEL_ONLINE (1<<4)
#define MEM_CANCEL_OFFLINE (1<<5)
/*
* All of these states are currently kernel-internal for notifying
* kernel components and architectures.
*
* For MEM_MAPPING_INVALID, all notifier chains with priority >0
* are called before pfn_to_page() becomes invalid. The priority=0
* entry is reserved for the function that actually makes
* pfn_to_page() stop working. Any notifiers that want to be called
* after that should have priority <0.
*/
#define MEM_MAPPING_INVALID (1<<3)
struct memory_notify {
unsigned long start_pfn;
unsigned long nr_pages;
int status_change_nid;
};
struct notifier_block;
struct mem_section;
......@@ -69,12 +66,18 @@ static inline int register_memory_notifier(struct notifier_block *nb)
static inline void unregister_memory_notifier(struct notifier_block *nb)
{
}
static inline int memory_notify(unsigned long val, void *v)
{
return 0;
}
#else
extern int register_memory_notifier(struct notifier_block *nb);
extern void unregister_memory_notifier(struct notifier_block *nb);
extern int register_new_memory(struct mem_section *);
extern int unregister_memory_section(struct mem_section *);
extern int memory_dev_init(void);
extern int remove_memory_block(unsigned long, struct mem_section *, int);
extern int memory_notify(unsigned long val, void *v);
#define CONFIG_MEM_BLOCK_SIZE (PAGES_PER_SECTION<<PAGE_SHIFT)
......
......@@ -187,7 +187,24 @@ int online_pages(unsigned long pfn, unsigned long nr_pages)
unsigned long onlined_pages = 0;
struct zone *zone;
int need_zonelists_rebuild = 0;
int nid;
int ret;
struct memory_notify arg;
arg.start_pfn = pfn;
arg.nr_pages = nr_pages;
arg.status_change_nid = -1;
nid = page_to_nid(pfn_to_page(pfn));
if (node_present_pages(nid) == 0)
arg.status_change_nid = nid;
ret = memory_notify(MEM_GOING_ONLINE, &arg);
ret = notifier_to_errno(ret);
if (ret) {
memory_notify(MEM_CANCEL_ONLINE, &arg);
return ret;
}
/*
* This doesn't need a lock to do pfn_to_page().
* The section can't be removed here because of the
......@@ -222,6 +239,10 @@ int online_pages(unsigned long pfn, unsigned long nr_pages)
build_all_zonelists();
vm_total_pages = nr_free_pagecache_pages();
writeback_set_ratelimit();
if (onlined_pages)
memory_notify(MEM_ONLINE, &arg);
return 0;
}
#endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */
......@@ -467,8 +488,9 @@ int offline_pages(unsigned long start_pfn,
{
unsigned long pfn, nr_pages, expire;
long offlined_pages;
int ret, drain, retry_max;
int ret, drain, retry_max, node;
struct zone *zone;
struct memory_notify arg;
BUG_ON(start_pfn >= end_pfn);
/* at least, alignment against pageblock is necessary */
......@@ -480,11 +502,27 @@ int offline_pages(unsigned long start_pfn,
we assume this for now. .*/
if (!test_pages_in_a_zone(start_pfn, end_pfn))
return -EINVAL;
zone = page_zone(pfn_to_page(start_pfn));
node = zone_to_nid(zone);
nr_pages = end_pfn - start_pfn;
/* set above range as isolated */
ret = start_isolate_page_range(start_pfn, end_pfn);
if (ret)
return ret;
nr_pages = end_pfn - start_pfn;
arg.start_pfn = start_pfn;
arg.nr_pages = nr_pages;
arg.status_change_nid = -1;
if (nr_pages >= node_present_pages(node))
arg.status_change_nid = node;
ret = memory_notify(MEM_GOING_OFFLINE, &arg);
ret = notifier_to_errno(ret);
if (ret)
goto failed_removal;
pfn = start_pfn;
expire = jiffies + timeout;
drain = 0;
......@@ -539,20 +577,24 @@ int offline_pages(unsigned long start_pfn,
/* reset pagetype flags */
start_isolate_page_range(start_pfn, end_pfn);
/* removal success */
zone = page_zone(pfn_to_page(start_pfn));
zone->present_pages -= offlined_pages;
zone->zone_pgdat->node_present_pages -= offlined_pages;
totalram_pages -= offlined_pages;
num_physpages -= offlined_pages;
vm_total_pages = nr_free_pagecache_pages();
writeback_set_ratelimit();
memory_notify(MEM_OFFLINE, &arg);
return 0;
failed_removal:
printk(KERN_INFO "memory offlining %lx to %lx failed\n",
start_pfn, end_pfn);
memory_notify(MEM_CANCEL_OFFLINE, &arg);
/* pushback to free area */
undo_isolate_page_range(start_pfn, end_pfn);
return ret;
}
#else
......
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