korg/linux
0
0
Fork 0
mirror of https://mirrors.bfsu.edu.cn/git/linux.git synced 2025-01-22 05:44:31 +08:00
Code Issues Packages Projects Releases Wiki Activity

xen: release unused free memory

Browse Source 
Scan an e820 table and release any memory which lies between e820 entries,
as it won't be used and would just be wasted.  At present this is just to
release any memory beyond the end of the e820 map, but it will also deal
with holes being punched in the map.

Derived from patch by Miroslav Rezanina <mrezanin@redhat.com>

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
This commit is contained in:
Miroslav Rezanina 2009-09-16 03:56:17 -04:00 committed by Jeremy Fitzhardinge
parent e40152ee1e
commit 093d7b4639
2 changed files with 53 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
arch/x86/xen/enlighten.c
View File

@ -731,7 +731,6 @@ static void set_xen_basic_apic_ops(void)
#endif
static void xen_clts(void)
{
struct multicall_space mcs;

53
arch/x86/xen/setup.c
View File

@ -20,6 +20,7 @@
#include <xen/page.h>
#include <xen/interface/callback.h>
#include <xen/interface/physdev.h>
#include <xen/interface/memory.h>
#include <xen/features.h>
#include "xen-ops.h"
@ -32,6 +33,56 @@ extern void xen_sysenter_target(void);
extern void xen_syscall_target(void);
extern void xen_syscall32_target(void);
static unsigned long __init xen_release_chunk(phys_addr_t start_addr, phys_addr_t end_addr)
{
struct xen_memory_reservation reservation = {
.address_bits = 0,
.extent_order = 0,
.domid = DOMID_SELF
};
unsigned long *mfn_list = (unsigned long *)xen_start_info->mfn_list;
unsigned long start, end;
unsigned long len;
unsigned long pfn;
int ret;
start = PFN_UP(start_addr);
end = PFN_UP(end_addr);
if (end <= start)
return 0;
len = end - start;
set_xen_guest_handle(reservation.extent_start, &mfn_list[start]);
reservation.nr_extents = len;
ret = HYPERVISOR_memory_op(XENMEM_decrease_reservation, &reservation);
WARN(ret != (end - start), "Failed to release memory %lx-%lx err=%d\n",
start, end, ret);
for(pfn = start; pfn < end; pfn++)
set_phys_to_machine(pfn, INVALID_P2M_ENTRY);
return len;
}
static unsigned long __init xen_return_unused_memory(const struct e820map *e820)
{
unsigned long last_end = 0;
unsigned long released = 0;
int i;
for (i = 0; i < e820->nr_map; i++) {
released += xen_release_chunk(last_end, e820->map[i].addr);
last_end = e820->map[i].addr + e820->map[i].size;
}
released += xen_release_chunk(last_end, PFN_PHYS(xen_start_info->nr_pages));
printk(KERN_INFO "released %ld pages of unused memory\n", released);
return released;
}
/**
* machine_specific_memory_setup - Hook for machine specific memory setup.
@ -67,6 +118,8 @@ char * __init xen_memory_setup(void)
sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
xen_return_unused_memory(&e820);
return "Xen";
}