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mm: allow memory hotplug and hibernation in the same kernel

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Allow memory hotplug and hibernation in the same kernel

Memory hotplug and hibernation were exclusive in Kconfig.  This is
obviously a problem for distribution kernels who want to support both in
the same image.

After some discussions with Rafael and others the only problem is with
parallel memory hotadd or removal while a hibernation operation is in
process.  It was also working for s390 before.

This patch removes the Kconfig level exclusion, and simply makes the
memory add / remove functions grab the pm_mutex to exclude against
hibernation.

Fixes a regression - old kernels didn't exclude memory hotadd and
hibernation.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Yasunori Goto <y-goto@jp.fujitsu.com>
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Andi Kleen 2009-11-17 14:06:22 -08:00 committed by Linus Torvalds
parent 9398180097
commit 6ad696d2cf
3 changed files with 37 additions and 10 deletions
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21
include/linux/suspend.h
View file

@ -301,6 +301,8 @@ static inline int unregister_pm_notifier(struct notifier_block *nb)
#define pm_notifier(fn, pri) do { (void)(fn); } while (0)
#endif /* !CONFIG_PM_SLEEP */
extern struct mutex pm_mutex;
#ifndef CONFIG_HIBERNATION
static inline void register_nosave_region(unsigned long b, unsigned long e)
{
@ -308,8 +310,23 @@ static inline void register_nosave_region(unsigned long b, unsigned long e)
static inline void register_nosave_region_late(unsigned long b, unsigned long e)
{
}
static inline void lock_system_sleep(void) {}
static inline void unlock_system_sleep(void) {}
#else
/* Let some subsystems like memory hotadd exclude hibernation */
static inline void lock_system_sleep(void)
{
mutex_lock(&pm_mutex);
}
static inline void unlock_system_sleep(void)
{
mutex_unlock(&pm_mutex);
}
#endif
extern struct mutex pm_mutex;
#endif /* _LINUX_SUSPEND_H */

5
mm/Kconfig
View file

@ -128,12 +128,9 @@ config SPARSEMEM_VMEMMAP
config MEMORY_HOTPLUG
bool "Allow for memory hot-add"
depends on SPARSEMEM || X86_64_ACPI_NUMA
depends on HOTPLUG && !(HIBERNATION && !S390) && ARCH_ENABLE_MEMORY_HOTPLUG
depends on HOTPLUG && ARCH_ENABLE_MEMORY_HOTPLUG
depends on (IA64 || X86 || PPC_BOOK3S_64 || SUPERH || S390)
comment "Memory hotplug is currently incompatible with Software Suspend"
depends on SPARSEMEM && HOTPLUG && HIBERNATION && !S390
config MEMORY_HOTPLUG_SPARSE
def_bool y
depends on SPARSEMEM && MEMORY_HOTPLUG

21
mm/memory_hotplug.c
View file

@ -26,6 +26,7 @@
#include <linux/migrate.h>
#include <linux/page-isolation.h>
#include <linux/pfn.h>
#include <linux/suspend.h>
#include <asm/tlbflush.h>
@ -485,14 +486,18 @@ int __ref add_memory(int nid, u64 start, u64 size)
struct resource *res;
int ret;
lock_system_sleep();
res = register_memory_resource(start, size);
ret = -EEXIST;
if (!res)
return -EEXIST;
goto out;
if (!node_online(nid)) {
pgdat = hotadd_new_pgdat(nid, start);
ret = -ENOMEM;
if (!pgdat)
return -ENOMEM;
goto out;
new_pgdat = 1;
}
@ -515,7 +520,8 @@ int __ref add_memory(int nid, u64 start, u64 size)
BUG_ON(ret);
}
return ret;
goto out;
error:
/* rollback pgdat allocation and others */
if (new_pgdat)
@ -523,6 +529,8 @@ error:
if (res)
release_memory_resource(res);
out:
unlock_system_sleep();
return ret;
}
EXPORT_SYMBOL_GPL(add_memory);
@ -759,6 +767,8 @@ int offline_pages(unsigned long start_pfn,
if (!test_pages_in_a_zone(start_pfn, end_pfn))
return -EINVAL;
lock_system_sleep();
zone = page_zone(pfn_to_page(start_pfn));
node = zone_to_nid(zone);
nr_pages = end_pfn - start_pfn;
@ -766,7 +776,7 @@ int offline_pages(unsigned long start_pfn,
/* set above range as isolated */
ret = start_isolate_page_range(start_pfn, end_pfn);
if (ret)
return ret;
goto out;
arg.start_pfn = start_pfn;
arg.nr_pages = nr_pages;
@ -844,6 +854,7 @@ repeat:
writeback_set_ratelimit();
memory_notify(MEM_OFFLINE, &arg);
unlock_system_sleep();
return 0;
failed_removal:
@ -853,6 +864,8 @@ failed_removal:
/* pushback to free area */
undo_isolate_page_range(start_pfn, end_pfn);
out:
unlock_system_sleep();
return ret;
}