From 68a3a7feb08f960095072f28ec20f7900793c506 Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Fri, 7 Apr 2006 19:49:18 +0200 Subject: [PATCH] x86_64: Reserve SRAT hotadd memory on x86-64 From: Keith Mannthey, Andi Kleen Implement memory hotadd without sparsemem. The memory in the SRAT hotadd area is just preserved instead and can be activated later. There are a few restrictions: - Only one continuous hotadd area allowed per node The main problem is dealing with the many buggy SRAT tables that are out there. The strategy here is to reject anything suspicious. Originally from Keith Mannthey, with several hacks and changes by AK and also contributions from Andrew Morton [ TBD: Problems pointed out by KAMEZAWA Hiroyuki : 1) Goto's rebuild_zonelist patch will not work if CONFIG_MEMORY_HOTPLUG=n. Rebuilding zonelist is necessary when the system has just memory < 4G at boot, and hot add memory > 4G. because x86_64 has DMA32, ZONE_NORAML is not included into zonelist at boot time if system doesn't have memory >4G at boot. [AK: should just force the higher zones at boot time when SRAT tells us] 2) zone and node's spanned_pages and present_pages are not incremented. They should be. For example, our server (ia64/Fujitsu PrimeQuest) can equip memory from 4G to 1T(maybe 2T in future), and SRAT will *always* say we have possible 1T +memory. (Microsoft requires "write all possible memory in SRAT") When we reserve memmap for possible 1T memory, Linux will not work well in +minimum 4G configuraion ;) [AK: needs limiting to 5-10% of max memory] ] Signed-off-by: Andi Kleen Signed-off-by: Linus Torvalds --- arch/x86_64/mm/srat.c | 164 ++++++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 158 insertions(+), 6 deletions(-) (limited to 'arch/x86_64/mm/srat.c') diff --git a/arch/x86_64/mm/srat.c b/arch/x86_64/mm/srat.c index 2eb879590dc..443875eb15a 100644 --- a/arch/x86_64/mm/srat.c +++ b/arch/x86_64/mm/srat.c @@ -15,15 +15,26 @@ #include #include #include +#include +#include #include #include #include +#if (defined(CONFIG_ACPI_HOTPLUG_MEMORY) || \ + defined(CONFIG_ACPI_HOTPLUG_MEMORY_MODULE)) \ + && !defined(CONFIG_MEMORY_HOTPLUG) +#define RESERVE_HOTADD 1 +#endif + static struct acpi_table_slit *acpi_slit; static nodemask_t nodes_parsed __initdata; 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; static u8 pxm2node[256] = { [0 ... 255] = 0xff }; /* Too small nodes confuse the VM badly. Usually they result @@ -71,6 +82,10 @@ static __init int conflicting_nodes(unsigned long start, unsigned long end) static __init void cutoff_node(int i, unsigned long start, unsigned long end) { struct bootnode *nd = &nodes[i]; + + if (found_add_area) + return; + if (nd->start < start) { nd->start = start; if (nd->end < nd->start) @@ -90,6 +105,8 @@ static __init void bad_srat(void) acpi_numa = -1; for (i = 0; i < MAX_LOCAL_APIC; i++) apicid_to_node[i] = NUMA_NO_NODE; + for (i = 0; i < MAX_NUMNODES; i++) + nodes_add[i].start = nodes[i].end = 0; } static __init inline int srat_disabled(void) @@ -155,11 +172,114 @@ acpi_numa_processor_affinity_init(struct acpi_table_processor_affinity *pa) pxm, pa->apic_id, node); } +#ifdef RESERVE_HOTADD +/* + * Protect against too large hotadd areas that would fill up memory. + */ +static int hotadd_enough_memory(struct bootnode *nd) +{ + static unsigned long allocated; + static unsigned long last_area_end; + unsigned long pages = (nd->end - nd->start) >> PAGE_SHIFT; + long mem = pages * sizeof(struct page); + unsigned long addr; + unsigned long allowed; + unsigned long oldpages = pages; + + if (mem < 0) + return 0; + allowed = (end_pfn - e820_hole_size(0, end_pfn)) * PAGE_SIZE; + allowed = (allowed / 100) * hotadd_percent; + if (allocated + mem > allowed) { + /* 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); + mem = pages * sizeof(struct page); + nd->end = nd->start + pages*PAGE_SIZE; + } + /* Not completely fool proof, but a good sanity check */ + addr = find_e820_area(last_area_end, end_pfn<> PAGE_SHIFT; + unsigned long e_pfn = end >> PAGE_SHIFT; + int changed = 0; + struct bootnode *nd = &nodes_add[node]; + + /* I had some trouble with strange memory hotadd regions breaking + the boot. Be very strict here and reject anything unexpected. + If you want working memory hotadd write correct SRATs. + + The node size check is a basic sanity check to guard against + mistakes */ + if ((signed long)(end - start) < NODE_MIN_SIZE) { + printk(KERN_ERR "SRAT: Hotplug area too small\n"); + return -1; + } + + /* 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) { + printk(KERN_ERR "SRAT: Hotplug area has existing memory\n"); + return -1; + } + + if (!hotadd_enough_memory(&nodes_add[node])) { + printk(KERN_ERR "SRAT: Hotplug area too large\n"); + return -1; + } + + /* Looks good */ + + found_add_area = 1; + if (nd->start == nd->end) { + nd->start = start; + nd->end = end; + changed = 1; + } else { + if (nd->start == end) { + nd->start = start; + changed = 1; + } + if (nd->end == start) { + nd->end = end; + changed = 1; + } + if (!changed) + printk(KERN_ERR "SRAT: Hotplug zone not continuous. Partly ignored\n"); + } + + if ((nd->end >> PAGE_SHIFT) > end_pfn) + end_pfn = nd->end >> PAGE_SHIFT; + + if (changed) + printk(KERN_INFO "SRAT: hot plug zone found %Lx - %Lx\n", nd->start, nd->end); + return 0; +} +#endif + /* Callback for parsing of the Proximity Domain <-> Memory Area mappings */ void __init acpi_numa_memory_affinity_init(struct acpi_table_memory_affinity *ma) { - struct bootnode *nd; + struct bootnode *nd, oldnode; unsigned long start, end; int node, pxm; int i; @@ -172,6 +292,8 @@ acpi_numa_memory_affinity_init(struct acpi_table_memory_affinity *ma) } if (ma->flags.enabled == 0) return; + if (ma->flags.hot_pluggable && hotadd_percent == 0) + return; start = ma->base_addr_lo | ((u64)ma->base_addr_hi << 32); end = start + (ma->length_lo | ((u64)ma->length_hi << 32)); pxm = ma->proximity_domain; @@ -181,10 +303,6 @@ acpi_numa_memory_affinity_init(struct acpi_table_memory_affinity *ma) bad_srat(); return; } - /* It is fine to add this area to the nodes data it will be used later*/ - if (ma->flags.hot_pluggable == 1) - printk(KERN_INFO "SRAT: hot plug zone found %lx - %lx \n", - start, end); i = conflicting_nodes(start, end); if (i == node) { printk(KERN_WARNING @@ -199,6 +317,7 @@ acpi_numa_memory_affinity_init(struct acpi_table_memory_affinity *ma) return; } nd = &nodes[node]; + oldnode = *nd; if (!node_test_and_set(node, nodes_parsed)) { nd->start = start; nd->end = end; @@ -208,8 +327,19 @@ acpi_numa_memory_affinity_init(struct acpi_table_memory_affinity *ma) if (nd->end < end) nd->end = end; } + printk(KERN_INFO "SRAT: Node %u PXM %u %Lx-%Lx\n", node, pxm, nd->start, nd->end); + +#ifdef RESERVE_HOTADD + if (ma->flags.hot_pluggable && reserve_hotadd(node, start, end) < 0) { + /* Ignore hotadd region. Undo damage */ + printk(KERN_NOTICE "SRAT: Hotplug region ignored\n"); + *nd = oldnode; + if ((nd->start | nd->end) == 0) + node_clear(node, nodes_parsed); + } +#endif } /* Sanity check to catch more bad SRATs (they are amazingly common). @@ -225,6 +355,9 @@ static int nodes_cover_memory(void) unsigned long e = nodes[i].end >> PAGE_SHIFT; pxmram += e - s; pxmram -= e820_hole_size(s, e); + pxmram -= nodes_add[i].end - nodes_add[i].start; + if ((long)pxmram < 0) + pxmram = 0; } e820ram = end_pfn - e820_hole_size(0, end_pfn); @@ -258,7 +391,7 @@ int __init acpi_scan_nodes(unsigned long start, unsigned long end) /* First clean up the node list */ for (i = 0; i < MAX_NUMNODES; i++) { - cutoff_node(i, start, end); + cutoff_node(i, start, end); if ((nodes[i].end - nodes[i].start) < NODE_MIN_SIZE) unparse_node(i); } @@ -303,6 +436,25 @@ static int node_to_pxm(int n) return 0; } +void __init srat_reserve_add_area(int nodeid) +{ + if (found_add_area && nodes_add[nodeid].end) { + u64 total_mb; + + printk(KERN_INFO "SRAT: Reserving hot-add memory space " + "for node %d at %Lx-%Lx\n", + nodeid, nodes_add[nodeid].start, nodes_add[nodeid].end); + total_mb = (nodes_add[nodeid].end - nodes_add[nodeid].start) + >> PAGE_SHIFT; + total_mb *= sizeof(struct page); + total_mb >>= 20; + printk(KERN_INFO "SRAT: This will cost you %Lu MB of " + "pre-allocated memory.\n", (unsigned long long)total_mb); + reserve_bootmem_node(NODE_DATA(nodeid), nodes_add[nodeid].start, + nodes_add[nodeid].end - nodes_add[nodeid].start); + } +} + int __node_distance(int a, int b) { int index; -- cgit v1.2.3 From a8062231d80239cf3405982858c02aea21a6066a Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Fri, 7 Apr 2006 19:49:21 +0200 Subject: [PATCH] x86_64: Handle empty PXMs that only contain hotplug memory The node setup code would try to allocate the node metadata in the node itself, but that fails if there is no memory in there. This can happen with memory hotplug when the hotplug area defines an so far empty node. Now use bootmem to try to allocate the mem_map in other nodes. And if it fails don't panic, but just ignore the node. To make this work I added a new __alloc_bootmem_nopanic function that does what its name implies. TBD should try to use nearby nodes here. Currently we just use any. It's hard to do it better because bootmem doesn't have proper fallback lists yet. Signed-off-by: Andi Kleen Signed-off-by: Linus Torvalds --- arch/x86_64/mm/srat.c | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'arch/x86_64/mm/srat.c') diff --git a/arch/x86_64/mm/srat.c b/arch/x86_64/mm/srat.c index 443875eb15a..15ae9fcd65a 100644 --- a/arch/x86_64/mm/srat.c +++ b/arch/x86_64/mm/srat.c @@ -415,6 +415,12 @@ int __init acpi_scan_nodes(unsigned long start, unsigned long end) /* Finally register nodes */ for_each_node_mask(i, nodes_parsed) setup_node_bootmem(i, nodes[i].start, nodes[i].end); + /* Try again in case setup_node_bootmem missed one due + to missing bootmem */ + for_each_node_mask(i, nodes_parsed) + if (!node_online(i)) + setup_node_bootmem(i, nodes[i].start, nodes[i].end); + for (i = 0; i < NR_CPUS; i++) { if (cpu_to_node[i] == NUMA_NO_NODE) continue; -- cgit v1.2.3