linux/include/xen/balloon.h
Daniel Kiper 080e2be788 xen/balloon: memory hotplug support for Xen balloon driver
Memory hotplug support for Xen balloon driver.  It should be mentioned
that hotplugged memory is not onlined automatically.  It should be onlined
by user through standard sysfs interface.

Memory could be hotplugged in following steps:

  1) dom0: xl mem-max <domU> <maxmem>
     where <maxmem> is >= requested memory size,

  2) dom0: xl mem-set <domU> <memory>
     where <memory> is requested memory size; alternatively memory
     could be added by writing proper value to
     /sys/devices/system/xen_memory/xen_memory0/target or
     /sys/devices/system/xen_memory/xen_memory0/target_kb on dumU,

  3) domU: for i in /sys/devices/system/memory/memory*/state; do \
             [ "`cat "$i"`" = offline ] && echo online > "$i"; done

Memory could be onlined automatically on domU by adding following line to
udev rules:

  SUBSYSTEM=="memory", ACTION=="add", RUN+="/bin/sh -c '[ -f /sys$devpath/state ] && echo online > /sys$devpath/state'"

In that case step 3 should be omitted.

Signed-off-by: Daniel Kiper <dkiper@net-space.pl>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Ian Campbell <ian.campbell@citrix.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-07-25 20:57:08 -07:00

40 lines
1.1 KiB
C

/******************************************************************************
* Xen balloon functionality
*/
#define RETRY_UNLIMITED 0
struct balloon_stats {
/* We aim for 'current allocation' == 'target allocation'. */
unsigned long current_pages;
unsigned long target_pages;
/* Number of pages in high- and low-memory balloons. */
unsigned long balloon_low;
unsigned long balloon_high;
unsigned long schedule_delay;
unsigned long max_schedule_delay;
unsigned long retry_count;
unsigned long max_retry_count;
#ifdef CONFIG_XEN_BALLOON_MEMORY_HOTPLUG
unsigned long hotplug_pages;
unsigned long balloon_hotplug;
#endif
};
extern struct balloon_stats balloon_stats;
void balloon_set_new_target(unsigned long target);
int alloc_xenballooned_pages(int nr_pages, struct page** pages);
void free_xenballooned_pages(int nr_pages, struct page** pages);
struct sys_device;
#ifdef CONFIG_XEN_SELFBALLOONING
extern int register_xen_selfballooning(struct sys_device *sysdev);
#else
static inline int register_xen_selfballooning(struct sys_device *sysdev)
{
return -ENOSYS;
}
#endif