Commit fad7906d authored by Andi Kleen's avatar Andi Kleen Committed by Linus Torvalds

[PATCH] x86_64: Fix memory hotadd heuristics

This fixes some boot failures on Dell and Unisys systems with memory
hotadd added.

 - Set hotadd_percent to 0 by default.  This means anybody using hotadd
   memory needs to specify the value on the command line.  That's
   because there are lots of Intel boxes which have a bogus hotplug area
   in their SRAT and they would waste a lot of memory before.
 - Fix calculation of how much memory to use when the hotplug area
   exceeds hotadd_percent
 - Fix fallback when the
 - Fix fallback if memory hotadd is not compiled in.
Signed-off-by: default avatarAndi Kleen <ak@suse.de>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 5491d0f3
......@@ -34,7 +34,10 @@ static nodemask_t nodes_found __initdata;
static struct bootnode nodes[MAX_NUMNODES] __initdata;
static struct bootnode nodes_add[MAX_NUMNODES] __initdata;
static int found_add_area __initdata;
int hotadd_percent __initdata = 10;
int hotadd_percent __initdata = 0;
#ifndef RESERVE_HOTADD
#define hotadd_percent 0 /* Ignore all settings */
#endif
static u8 pxm2node[256] = { [0 ... 255] = 0xff };
/* Too small nodes confuse the VM badly. Usually they result
......@@ -103,6 +106,7 @@ static __init void bad_srat(void)
int i;
printk(KERN_ERR "SRAT: SRAT not used.\n");
acpi_numa = -1;
found_add_area = 0;
for (i = 0; i < MAX_LOCAL_APIC; i++)
apicid_to_node[i] = NUMA_NO_NODE;
for (i = 0; i < MAX_NUMNODES; i++)
......@@ -154,7 +158,8 @@ acpi_numa_processor_affinity_init(struct acpi_table_processor_affinity *pa)
int pxm, node;
if (srat_disabled())
return;
if (pa->header.length != sizeof(struct acpi_table_processor_affinity)) { bad_srat();
if (pa->header.length != sizeof(struct acpi_table_processor_affinity)) {
bad_srat();
return;
}
if (pa->flags.enabled == 0)
......@@ -191,15 +196,17 @@ static int hotadd_enough_memory(struct bootnode *nd)
allowed = (end_pfn - e820_hole_size(0, end_pfn)) * PAGE_SIZE;
allowed = (allowed / 100) * hotadd_percent;
if (allocated + mem > allowed) {
unsigned long range;
/* Give them at least part of their hotadd memory upto hotadd_percent
It would be better to spread the limit out
over multiple hotplug areas, but that is too complicated
right now */
if (allocated >= allowed)
return 0;
pages = (allowed - allocated + mem) / sizeof(struct page);
range = allowed - allocated;
pages = (range / PAGE_SIZE);
mem = pages * sizeof(struct page);
nd->end = nd->start + pages*PAGE_SIZE;
nd->end = nd->start + range;
}
/* Not completely fool proof, but a good sanity check */
addr = find_e820_area(last_area_end, end_pfn<<PAGE_SHIFT, mem);
......
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