1cf6a6c829
alloc_xenballooned_pages() is used to get ballooned pages to back foreign mappings etc. Instead of having to balloon out real pages, use (if supported) hotplugged memory. This makes more memory available to the guest and reduces fragmentation in the p2m. This is only enabled if the xen.balloon.hotplug_unpopulated sysctl is set to 1. This sysctl defaults to 0 in case the udev rules to automatically online hotplugged memory do not exist. Signed-off-by: David Vrabel <david.vrabel@citrix.com> Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com> --- v3: - Add xen.balloon.hotplug_unpopulated sysctl to enable use of hotplug for unpopulated pages.
38 lines
1 KiB
C
38 lines
1 KiB
C
/******************************************************************************
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* Xen balloon functionality
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*/
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#define RETRY_UNLIMITED 0
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struct balloon_stats {
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/* We aim for 'current allocation' == 'target allocation'. */
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unsigned long current_pages;
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unsigned long target_pages;
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unsigned long target_unpopulated;
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/* Number of pages in high- and low-memory balloons. */
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unsigned long balloon_low;
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unsigned long balloon_high;
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unsigned long total_pages;
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unsigned long schedule_delay;
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unsigned long max_schedule_delay;
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unsigned long retry_count;
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unsigned long max_retry_count;
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};
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extern struct balloon_stats balloon_stats;
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void balloon_set_new_target(unsigned long target);
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int alloc_xenballooned_pages(int nr_pages, struct page **pages);
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void free_xenballooned_pages(int nr_pages, struct page **pages);
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struct device;
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#ifdef CONFIG_XEN_SELFBALLOONING
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extern int register_xen_selfballooning(struct device *dev);
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#else
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static inline int register_xen_selfballooning(struct device *dev)
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{
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return -ENOSYS;
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}
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#endif
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