diff options
Diffstat (limited to 'arch/x86_64')
| -rw-r--r-- | arch/x86_64/kernel/e820.c | 31 | ||||
| -rw-r--r-- | arch/x86_64/mm/numa.c | 110 |
2 files changed, 127 insertions, 14 deletions
diff --git a/arch/x86_64/kernel/e820.c b/arch/x86_64/kernel/e820.c index 9d67955bbc3..4651fd22b21 100644 --- a/arch/x86_64/kernel/e820.c +++ b/arch/x86_64/kernel/e820.c @@ -191,6 +191,37 @@ unsigned long __init e820_end_of_ram(void) } /* + * Find the hole size in the range. + */ +unsigned long __init e820_hole_size(unsigned long start, unsigned long end) +{ + unsigned long ram = 0; + int i; + + for (i = 0; i < e820.nr_map; i++) { + struct e820entry *ei = &e820.map[i]; + unsigned long last, addr; + + if (ei->type != E820_RAM || + ei->addr+ei->size <= start || + ei->addr >= end) + continue; + + addr = round_up(ei->addr, PAGE_SIZE); + if (addr < start) + addr = start; + + last = round_down(ei->addr + ei->size, PAGE_SIZE); + if (last >= end) + last = end; + + if (last > addr) + ram += last - addr; + } + return ((end - start) - ram); +} + +/* * Mark e820 reserved areas as busy for the resource manager. */ void __init e820_reserve_resources(void) diff --git a/arch/x86_64/mm/numa.c b/arch/x86_64/mm/numa.c index 1ec16ea9751..d3f747dd61d 100644 --- a/arch/x86_64/mm/numa.c +++ b/arch/x86_64/mm/numa.c @@ -272,31 +272,113 @@ void __init numa_init_array(void) } #ifdef CONFIG_NUMA_EMU +/* Numa emulation */ int numa_fake __initdata = 0; -/* Numa emulation */ +/* + * This function is used to find out if the start and end correspond to + * different zones. + */ +int zone_cross_over(unsigned long start, unsigned long end) +{ + if ((start < (MAX_DMA32_PFN << PAGE_SHIFT)) && + (end >= (MAX_DMA32_PFN << PAGE_SHIFT))) + return 1; + return 0; +} + static int __init numa_emulation(unsigned long start_pfn, unsigned long end_pfn) { - int i; + int i, big; struct bootnode nodes[MAX_NUMNODES]; - unsigned long sz = ((end_pfn - start_pfn)<<PAGE_SHIFT) / numa_fake; + unsigned long sz, old_sz; + unsigned long hole_size; + unsigned long start, end; + unsigned long max_addr = (end_pfn << PAGE_SHIFT); + + start = (start_pfn << PAGE_SHIFT); + hole_size = e820_hole_size(start, max_addr); + sz = (max_addr - start - hole_size) / numa_fake; /* Kludge needed for the hash function */ - if (hweight64(sz) > 1) { - unsigned long x = 1; - while ((x << 1) < sz) - x <<= 1; - if (x < sz/2) - printk(KERN_ERR "Numa emulation unbalanced. Complain to maintainer\n"); - sz = x; - } + old_sz = sz; + /* + * Round down to the nearest FAKE_NODE_MIN_SIZE. + */ + sz &= FAKE_NODE_MIN_HASH_MASK; + + /* + * We ensure that each node is at least 64MB big. Smaller than this + * size can cause VM hiccups. + */ + if (sz == 0) { + printk(KERN_INFO "Not enough memory for %d nodes. Reducing " + "the number of nodes\n", numa_fake); + numa_fake = (max_addr - start - hole_size) / FAKE_NODE_MIN_SIZE; + printk(KERN_INFO "Number of fake nodes will be = %d\n", + numa_fake); + sz = FAKE_NODE_MIN_SIZE; + } + /* + * Find out how many nodes can get an extra NODE_MIN_SIZE granule. + * This logic ensures the extra memory gets distributed among as many + * nodes as possible (as compared to one single node getting all that + * extra memory. + */ + big = ((old_sz - sz) * numa_fake) / FAKE_NODE_MIN_SIZE; + printk(KERN_INFO "Fake node Size: %luMB hole_size: %luMB big nodes: " + "%d\n", + (sz >> 20), (hole_size >> 20), big); memset(&nodes,0,sizeof(nodes)); + end = start; for (i = 0; i < numa_fake; i++) { - nodes[i].start = (start_pfn<<PAGE_SHIFT) + i*sz; + /* + * In case we are not able to allocate enough memory for all + * the nodes, we reduce the number of fake nodes. + */ + if (end >= max_addr) { + numa_fake = i - 1; + break; + } + start = nodes[i].start = end; + /* + * Final node can have all the remaining memory. + */ if (i == numa_fake-1) - sz = (end_pfn<<PAGE_SHIFT) - nodes[i].start; - nodes[i].end = nodes[i].start + sz; + sz = max_addr - start; + end = nodes[i].start + sz; + /* + * Fir "big" number of nodes get extra granule. + */ + if (i < big) + end += FAKE_NODE_MIN_SIZE; + /* + * Iterate over the range to ensure that this node gets at + * least sz amount of RAM (excluding holes) + */ + while ((end - start - e820_hole_size(start, end)) < sz) { + end += FAKE_NODE_MIN_SIZE; + if (end >= max_addr) + break; + } + /* + * Look at the next node to make sure there is some real memory + * to map. Bad things happen when the only memory present + * in a zone on a fake node is IO hole. + */ + while (e820_hole_size(end, end + FAKE_NODE_MIN_SIZE) > 0) { + if (zone_cross_over(start, end + sz)) { + end = (MAX_DMA32_PFN << PAGE_SHIFT); + break; + } + if (end >= max_addr) + break; + end += FAKE_NODE_MIN_SIZE; + } + if (end > max_addr) + end = max_addr; + nodes[i].end = end; printk(KERN_INFO "Faking node %d at %016Lx-%016Lx (%LuMB)\n", i, nodes[i].start, nodes[i].end, |