Re: [PATCH 4/6] Have x86_64 use add_active_range() and free_area_init_nodes

From: Keith Mannthey
Date: Wed Aug 30 2006 - 16:54:35 EST


On 8/21/06, Mel Gorman <mel@xxxxxxxxx> wrote:

Size zones and holes in an architecture independent manner for x86_64.


Hey Mel,
I am having some trouble with the srat.c changes. I keep running into
"SRAT: Hotplug area has existing memory" so am am taking more throught
look at this patch.
I am working on 2.6.18-rc4-mm3 x86_64.

srat.c is doing some sanity checking against the e820 and hot-add
memory ranges. BIOS folk aren't to be trusted with the SRAT. Calling
remove_all_active_ranges before acpi_numa_init leaves nothing to fall
back onto if the SRAT is bad. (see bad_srat()). What should happen
when we discard the srat info?

i386 code may have similar fallback logic (haven't been there in a while)

also

diff -rup -X /usr/src/patchset-0.6/bin//dontdiff linux-2.6.18-rc4-mm2-103-x86_use_init_nodes/arch/x86_64/mm/srat.c linux-2.6.18-rc4-mm2-104-x86_64_use_init_nodes/arch/x86_64/mm/srat.c
--- linux-2.6.18-rc4-mm2-103-x86_use_init_nodes/arch/x86_64/mm/srat.c 2006-08-21 09:23:50.000000000 +0100
+++ linux-2.6.18-rc4-mm2-104-x86_64_use_init_nodes/arch/x86_64/mm/srat.c 2006-08-21 10:15:58.000000000 +0100
@@ -84,6 +84,7 @@ static __init void bad_srat(void)
apicid_to_node[i] = NUMA_NO_NODE;
for (i = 0; i < MAX_NUMNODES; i++)
nodes_add[i].start = nodes[i].end = 0;
+ remove_all_active_ranges();
}

We go back to setup_arch with no active areas?

static __init inline int srat_disabled(void)
@@ -166,7 +167,7 @@ static int hotadd_enough_memory(struct b

if (mem < 0)
return 0;
- allowed = (end_pfn - e820_hole_size(0, end_pfn)) * PAGE_SIZE;
+ allowed = (end_pfn - absent_pages_in_range(0, end_pfn)) * PAGE_SIZE;
allowed = (allowed / 100) * hotadd_percent;
if (allocated + mem > allowed) {
unsigned long range;
@@ -238,7 +239,7 @@ static int reserve_hotadd(int node, unsi
}

/* This check might be a bit too strict, but I'm keeping it for now. */
- if (e820_hole_size(s_pfn, e_pfn) != e_pfn - s_pfn) {
+ if (absent_pages_in_range(s_pfn, e_pfn) != e_pfn - s_pfn) {
printk(KERN_ERR "SRAT: Hotplug area has existing memory\n");
return -1;
}
We really do want to to compare against the e820 map at it contains
the memory that is really present (this info was blown away before
acpi_numa) Anyway I fixed up to have the current chunk added
(e820_register_active_regions) after calling this code so it logicaly
makes sense but it still trip over the check. I am not sure what you
are printing out in you debug code but dosen't look like pfns or
phys_addresses but maybe it can tell us why the check fails.

@@ -329,6 +330,8 @@ acpi_numa_memory_affinity_init(struct ac

printk(KERN_INFO "SRAT: Node %u PXM %u %Lx-%Lx\n", node, pxm,
nd->start, nd->end);
+ e820_register_active_regions(node, nd->start >> PAGE_SHIFT,
+ nd->end >> PAGE_SHIFT);

A node chunk in this section of code may be a hot-pluggable zone. With
MEMORY_HOTPLUG_SPARSE we don't want to register these regions.

if (ma->flags.hot_pluggable && !reserve_hotadd(node, start, end) < 0) {
/* Ignore hotadd region. Undo damage */

I have but the e820_register_active_regions as a else to this
statment the absent pages check fails.

Also nodes_cover_memory and alot of these check were based against
comparing the srat data against the e820. Now all this code is
comparing SRAT against SRAT....

I am willing to help here but we should compare the SRAT against to
e820. Table v. Table.

What to you think should be done?

Thanks,
Keith

Linux version 2.6.18-rc4-mm3-smp (root@elm3a153) (gcc version 4.1.0
(SUSE Linux)) #3 SMP Wed Aug 30 15:17:13 EDT 2006
Command line: root=/dev/sda3
ip=9.47.66.153:9.47.66.169:9.47.66.1:255.255.255.0 resume=/dev/sda2
showopts earlyprintk=ttyS0,115200 console=ttyS0,115200 console=tty0
debug numa=hotadd=100
BIOS-provided physical RAM map:
BIOS-e820: 0000000000000000 - 0000000000098400 (usable)
BIOS-e820: 0000000000098400 - 00000000000a0000 (reserved)
BIOS-e820: 00000000000e0000 - 0000000000100000 (reserved)
BIOS-e820: 0000000000100000 - 000000007ff85e00 (usable)
BIOS-e820: 000000007ff85e00 - 000000007ff98880 (ACPI data)
BIOS-e820: 000000007ff98880 - 0000000080000000 (reserved)
BIOS-e820: 00000000fec00000 - 0000000100000000 (reserved)
BIOS-e820: 0000000100000000 - 0000000470000000 (usable)
BIOS-e820: 0000001070000000 - 0000001160000000 (usable)
Entering add_active_range(0, 0, 152) 0 entries of 3200 used
Entering add_active_range(0, 256, 524165) 1 entries of 3200 used
Entering add_active_range(0, 1048576, 4653056) 2 entries of 3200 used
Entering add_active_range(0, 17235968, 18219008) 3 entries of 3200 used
end_pfn_map = 18219008
DMI 2.3 present.
ACPI: RSDP (v000 IBM ) @ 0x00000000000fdcf0
ACPI: RSDT (v001 IBM EXA01ZEU 0x00001000 IBM 0x45444f43) @
0x000000007ff98800
ACPI: FADT (v001 IBM EXA01ZEU 0x00001000 IBM 0x45444f43) @
0x000000007ff98780
ACPI: MADT (v001 IBM EXA01ZEU 0x00001000 IBM 0x45444f43) @
0x000000007ff98600
ACPI: SRAT (v001 IBM EXA01ZEU 0x00001000 IBM 0x45444f43) @
0x000000007ff983c0
ACPI: HPET (v001 IBM EXA01ZEU 0x00001000 IBM 0x45444f43) @
0x000000007ff98380
ACPI: SSDT (v001 IBM VIGSSDT0 0x00001000 INTL 0x20030122) @
0x000000007ff90780
ACPI: SSDT (v001 IBM VIGSSDT1 0x00001000 INTL 0x20030122) @
0x000000007ff88bc0
ACPI: DSDT (v001 IBM EXA01ZEU 0x00001000 INTL 0x20030122) @
0x0000000000000000
SRAT: PXM 0 -> APIC 0 -> Node 0
SRAT: PXM 0 -> APIC 1 -> Node 0
SRAT: PXM 0 -> APIC 2 -> Node 0
SRAT: PXM 0 -> APIC 3 -> Node 0
SRAT: PXM 0 -> APIC 38 -> Node 0
SRAT: PXM 0 -> APIC 39 -> Node 0
SRAT: PXM 0 -> APIC 36 -> Node 0
SRAT: PXM 0 -> APIC 37 -> Node 0
SRAT: PXM 1 -> APIC 64 -> Node 1
SRAT: PXM 1 -> APIC 65 -> Node 1
SRAT: PXM 1 -> APIC 66 -> Node 1
SRAT: PXM 1 -> APIC 67 -> Node 1
SRAT: PXM 1 -> APIC 102 -> Node 1
SRAT: PXM 1 -> APIC 103 -> Node 1
SRAT: PXM 1 -> APIC 100 -> Node 1
SRAT: PXM 1 -> APIC 101 -> Node 1
SRAT: Node 0 PXM 0 0-80000000
Entering add_active_range(0, 0, 152) 0 entries of 3200 used
Entering add_active_range(0, 256, 524165) 1 entries of 3200 used
SRAT: Node 0 PXM 0 0-470000000
Entering add_active_range(0, 0, 152) 2 entries of 3200 used
Entering add_active_range(0, 256, 524165) 2 entries of 3200 used
Entering add_active_range(0, 1048576, 4653056) 2 entries of 3200 used
SRAT: Node 0 PXM 0 0-1070000000
SRAT: Hotplug area has existing memory
Entering add_active_range(0, 0, 152) 3 entries of 3200 used
Entering add_active_range(0, 256, 524165) 3 entries of 3200 used
Entering add_active_range(0, 1048576, 4653056) 3 entries of 3200 used
SRAT: Node 1 PXM 1 1070000000-1160000000
Entering add_active_range(1, 17235968, 18219008) 3 entries of 3200 used
SRAT: Node 1 PXM 1 1070000000-3200000000
SRAT: Hotplug area has existing memory
Entering add_active_range(1, 17235968, 18219008) 4 entries of 3200 used
NUMA: Using 28 for the hash shift.
Bootmem setup node 0 0000000000000000-0000001070000000
Bootmem setup node 1 0000001070000000-0000001160000000
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