+
+/*
+ * percpu_pagelist_fraction - changes the pcp->high for each zone on each
+ * cpu. It is the fraction of total pages in each zone that a hot per cpu pagelist
+ * can have before it gets flushed back to buddy allocator.
+ */
+
+int percpu_pagelist_fraction_sysctl_handler(ctl_table *table, int write,
+ struct file *file, void __user *buffer, size_t *length, loff_t *ppos)
+{
+ struct zone *zone;
+ unsigned int cpu;
+ int ret;
+
+ ret = proc_dointvec_minmax(table, write, file, buffer, length, ppos);
+ if (!write || (ret == -EINVAL))
+ return ret;
+ for_each_zone(zone) {
+ for_each_online_cpu(cpu) {
+ unsigned long high;
+ high = zone->present_pages / percpu_pagelist_fraction;
+ setup_pagelist_highmark(zone_pcp(zone, cpu), high);
+ }
+ }
+ return 0;
+}
+
+__initdata int hashdist = HASHDIST_DEFAULT;
+
+#ifdef CONFIG_NUMA
+static int __init set_hashdist(char *str)
+{
+ if (!str)
+ return 0;
+ hashdist = simple_strtoul(str, &str, 0);
+ return 1;
+}
+__setup("hashdist=", set_hashdist);
+#endif
+
+/*
+ * allocate a large system hash table from bootmem
+ * - it is assumed that the hash table must contain an exact power-of-2
+ * quantity of entries
+ * - limit is the number of hash buckets, not the total allocation size
+ */
+void *__init alloc_large_system_hash(const char *tablename,
+ unsigned long bucketsize,
+ unsigned long numentries,
+ int scale,
+ int flags,
+ unsigned int *_hash_shift,
+ unsigned int *_hash_mask,
+ unsigned long limit)
+{
+ unsigned long long max = limit;
+ unsigned long log2qty, size;
+ void *table = NULL;
+
+ /* allow the kernel cmdline to have a say */
+ if (!numentries) {
+ /* round applicable memory size up to nearest megabyte */
+ numentries = (flags & HASH_HIGHMEM) ? nr_all_pages : nr_kernel_pages;
+ numentries += (1UL << (20 - PAGE_SHIFT)) - 1;
+ numentries >>= 20 - PAGE_SHIFT;
+ numentries <<= 20 - PAGE_SHIFT;
+
+ /* limit to 1 bucket per 2^scale bytes of low memory */
+ if (scale > PAGE_SHIFT)
+ numentries >>= (scale - PAGE_SHIFT);
+ else
+ numentries <<= (PAGE_SHIFT - scale);
+ }
+ numentries = roundup_pow_of_two(numentries);
+
+ /* limit allocation size to 1/16 total memory by default */
+ if (max == 0) {
+ max = ((unsigned long long)nr_all_pages << PAGE_SHIFT) >> 4;
+ do_div(max, bucketsize);
+ }
+
+ if (numentries > max)
+ numentries = max;
+
+ log2qty = long_log2(numentries);
+
+ do {
+ size = bucketsize << log2qty;
+ if (flags & HASH_EARLY)
+ table = alloc_bootmem(size);
+ else if (hashdist)
+ table = __vmalloc(size, GFP_ATOMIC, PAGE_KERNEL);
+ else {
+ unsigned long order;
+ for (order = 0; ((1UL << order) << PAGE_SHIFT) < size; order++)
+ ;
+ table = (void*) __get_free_pages(GFP_ATOMIC, order);
+ }
+ } while (!table && size > PAGE_SIZE && --log2qty);
+
+ if (!table)
+ panic("Failed to allocate %s hash table\n", tablename);
+
+ printk("%s hash table entries: %d (order: %d, %lu bytes)\n",
+ tablename,
+ (1U << log2qty),
+ long_log2(size) - PAGE_SHIFT,
+ size);
+
+ if (_hash_shift)
+ *_hash_shift = log2qty;
+ if (_hash_mask)
+ *_hash_mask = (1 << log2qty) - 1;
+
+ return table;
+}
+
+#ifdef CONFIG_OUT_OF_LINE_PFN_TO_PAGE
+struct page *pfn_to_page(unsigned long pfn)
+{
+ return __pfn_to_page(pfn);
+}
+unsigned long page_to_pfn(struct page *page)
+{
+ return __page_to_pfn(page);
+}
+EXPORT_SYMBOL(pfn_to_page);
+EXPORT_SYMBOL(page_to_pfn);
+#endif /* CONFIG_OUT_OF_LINE_PFN_TO_PAGE */