From d02bd27bd33dd7e8d22594cd568b81be0cb584cd Mon Sep 17 00:00:00 2001 From: Igor Redko Date: Thu, 17 Mar 2016 14:19:05 -0700 Subject: mm/page_alloc.c: calculate 'available' memory in a separate function Add a new field, VIRTIO_BALLOON_S_AVAIL, to virtio_balloon memory statistics protocol, corresponding to 'Available' in /proc/meminfo. It indicates to the hypervisor how big the balloon can be inflated without pushing the guest system to swap. This metric would be very useful in VM orchestration software to improve memory management of different VMs under overcommit. This patch (of 2): Factor out calculation of the available memory counter into a separate exportable function, in order to be able to use it in other parts of the kernel. In particular, it appears a relevant metric to report to the hypervisor via virtio-balloon statistics interface (in a followup patch). Signed-off-by: Igor Redko Signed-off-by: Denis V. Lunev Reviewed-by: Roman Kagan Cc: Michael S. Tsirkin Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/mm.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include') diff --git a/include/linux/mm.h b/include/linux/mm.h index b3202612bb95..db9df3f78de1 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1875,6 +1875,7 @@ extern int __meminit init_per_zone_wmark_min(void); extern void mem_init(void); extern void __init mmap_init(void); extern void show_mem(unsigned int flags); +extern long si_mem_available(void); extern void si_meminfo(struct sysinfo * val); extern void si_meminfo_node(struct sysinfo *val, int nid); -- cgit v1.2.3