linux-yocto - Yocto Linux Embedded kernel

Age	Commit message (Expand)	Author
2020-08-12	mm/zpool.c: delete duplicated word and fix grammar	Randy Dunlap
2019-09-24	zpool: add malloc_support_movable to zpool_driver	Hui Zhu
2019-05-21	treewide: Add SPDX license identifier for more missed files	Thomas Gleixner
2018-02-21	mm/zpool.c: zpool_evictable: fix mismatch in parameter name and kernel-doc	Mike Rapoport
2018-02-06	mm: docs: fix parameter names mismatch	Mike Rapoport
2018-02-06	mm: docs: fixup punctuation	Mike Rapoport
2018-01-31	zswap: only save zswap header when necessary	Yu Zhao
2015-11-06	mm: zsmalloc: constify struct zs_pool name	Sergey SENOZHATSKY
2015-11-06	zpool: remove redundant zpool->type string, const-ify zpool_get_type	Dan Streetman
2015-09-10	zpool: add zpool_has_pool()	Dan Streetman
2015-09-08	zpool: remove no-op module init/exit	Dan Streetman
2015-09-08	mm: zpool: constify the zpool_ops	Krzysztof Kozlowski
2015-06-25	zpool: remove zpool_evict()	Dan Streetman
2015-06-25	zpool: change pr_info to pr_debug	Dan Streetman
2015-02-12	mm/zpool: add name argument to create zpool	Ganesh Mahendran
2014-08-29	mm/zpool: use prefixed module loading	Kees Cook
2014-08-06	mm/zpool: implement common zpool api to zbud/zsmalloc	Dan Streetman

#include <linux/mm.h> #include <linux/mmzone.h> #include <linux/bootmem.h> #include <linux/page_ext.h> #include <linux/memory.h> #include <linux/vmalloc.h> #include <linux/kmemleak.h> #include <linux/page_owner.h> #include <linux/page_idle.h> /* * struct page extension * * This is the feature to manage memory for extended data per page. * * Until now, we must modify struct page itself to store extra data per page. * This requires rebuilding the kernel and it is really time consuming process. * And, sometimes, rebuild is impossible due to third party module dependency. * At last, enlarging struct page could cause un-wanted system behaviour change. * * This feature is intended to overcome above mentioned problems. This feature * allocates memory for extended data per page in certain place rather than * the struct page itself. This memory can be accessed by the accessor * functions provided by this code. During the boot process, it checks whether * allocation of huge chunk of memory is needed or not. If not, it avoids * allocating memory at all. With this advantage, we can include this feature * into the kernel in default and can avoid rebuild and solve related problems. * * To help these things to work well, there are two callbacks for clients. One * is the need callback which is mandatory if user wants to avoid useless * memory allocation at boot-time. The other is optional, init callback, which * is used to do proper initialization after memory is allocated. * * The need callback is used to decide whether extended memory allocation is * needed or not. Sometimes users want to deactivate some features in this * boot and extra memory would be unneccessary. In this case, to avoid * allocating huge chunk of memory, each clients represent their need of * extra memory through the need callback. If one of the need callbacks * returns true, it means that someone needs extra memory so that * page extension core should allocates memory for page extension. If * none of need callbacks return true, memory isn't needed at all in this boot * and page extension core can skip to allocate memory. As result, * none of memory is wasted. * * The init callback is used to do proper initialization after page extension * is completely initialized. In sparse memory system, extra memory is * allocated some time later than memmap is allocated. In other words, lifetime * of memory for page extension isn't same with memmap for struct page. * Therefore, clients can't store extra data until page extension is * initialized, even if pages are allocated and used freely. This could * cause inadequate state of extra data per page, so, to prevent it, client * can utilize this callback to initialize the state of it correctly. */ static struct page_ext_operations *page_ext_ops[] = { &debug_guardpage_ops, #ifdef CONFIG_PAGE_POISONING &page_poisoning_ops, #endif #ifdef CONFIG_PAGE_OWNER &page_owner_ops, #endif #if defined(CONFIG_IDLE_PAGE_TRACKING) && !defined(CONFIG_64BIT) &page_idle_ops, #endif }; static unsigned long total_usage; static bool __init invoke_need_callbacks(void) { int i; int entries = ARRAY_SIZE(page_ext_ops); for (i = 0; i < entries; i++) { if (page_ext_ops[i]->need && page_ext_ops[i]->need()) return true; } return false; } static void __init invoke_init_callbacks(void) { int i; int entries = ARRAY_SIZE(page_ext_ops); for (i = 0; i < entries; i++) { if (page_ext_ops[i]->init) page_ext_ops[i]->init(); } } #if !defined(CONFIG_SPARSEMEM) void __meminit pgdat_page_ext_init(struct pglist_data *pgdat) { pgdat->node_page_ext = NULL; } struct page_ext *lookup_page_ext(struct page *page) { unsigned long pfn = page_to_pfn(page); unsigned long offset; struct page_ext *base; base = NODE_DATA(page_to_nid(page))->node_page_ext; #if defined(CONFIG_DEBUG_VM) || defined(CONFIG_PAGE_POISONING) /* * The sanity checks the page allocator does upon freeing a * page can reach here before the page_ext arrays are * allocated when feeding a range of pages to the allocator * for the first time during bootup or memory hotplug. * * This check is also necessary for ensuring page poisoning * works as expected when enabled */ if (unlikely(!base)) return NULL; #endif offset = pfn - round_down(node_start_pfn(page_to_nid(page)), MAX_ORDER_NR_PAGES); return base + offset; } static int __init alloc_node_page_ext(int nid) { struct page_ext *base; unsigned long table_size; unsigned long nr_pages; nr_pages = NODE_DATA(nid)->node_spanned_pages; if (!nr_pages) return 0; /* * Need extra space if node range is not aligned with * MAX_ORDER_NR_PAGES. When page allocator's buddy algorithm * checks buddy's status, range could be out of exact node range. */ if (!IS_ALIGNED(node_start_pfn(nid), MAX_ORDER_NR_PAGES) || !IS_ALIGNED(node_end_pfn(nid), MAX_ORDER_NR_PAGES)) nr_pages += MAX_ORDER_NR_PAGES; table_size = sizeof(struct page_ext) * nr_pages; base = memblock_virt_alloc_try_nid_nopanic( table_size, PAGE_SIZE, __pa(MAX_DMA_ADDRESS), BOOTMEM_ALLOC_ACCESSIBLE, nid); if (!base) return -ENOMEM; NODE_DATA(nid)->node_page_ext = base; total_usage += table_size; return 0; } void __init page_ext_init_flatmem(void) { int nid, fail; if (!invoke_need_callbacks()) return; for_each_online_node(nid) { fail = alloc_node_page_ext(nid); if (fail) goto fail; } pr_info("allocated %ld bytes of page_ext\n", total_usage); invoke_init_callbacks(); return; fail: pr_crit("allocation of page_ext failed.\n"); panic("Out of memory"); } #else /* CONFIG_FLAT_NODE_MEM_MAP */ struct page_ext *lookup_page_ext(struct page *page) { unsigned long pfn = page_to_pfn(page); struct mem_section *section = __pfn_to_section(pfn); #if defined(CONFIG_DEBUG_VM) || defined(CONFIG_PAGE_POISONING) /* * The sanity checks the page allocator does upon freeing a * page can reach here before the page_ext arrays are * allocated when feeding a range of pages to the allocator * for the first time during bootup or memory hotplug. * * This check is also necessary for ensuring page poisoning * works as expected when enabled */ if (!section->page_ext) return NULL; #endif return section->page_ext + pfn; } static void *__meminit alloc_page_ext(size_t size, int nid) { gfp_t flags = GFP_KERNEL | __GFP_ZERO | __GFP_NOWARN; void *addr = NULL; addr = alloc_pages_exact_nid(nid, size, flags); if (addr) { kmemleak_alloc(addr, size, 1, flags); return addr; } if (node_state(nid, N_HIGH_MEMORY)) addr = vzalloc_node(size, nid); else addr = vzalloc(size); return addr; } static int __meminit init_section_page_ext(unsigned long pfn, int nid) { struct mem_section *section; struct page_ext *base; unsigned long table_size; section = __pfn_to_section(pfn); if (section->page_ext) return 0; table_size = sizeof(struct page_ext) * PAGES_PER_SECTION; base = alloc_page_ext(table_size, nid); /* * The value stored in section->page_ext is (base - pfn) * and it does not point to the memory block allocated above, * causing kmemleak false positives. */ kmemleak_not_leak(base); if (!base) { pr_err("page ext allocation failure\n"); return -ENOMEM; } /* * The passed "pfn" may not be aligned to SECTION. For the calculation * we need to apply a mask. */ pfn &= PAGE_SECTION_MASK; section->page_ext = base - pfn; total_usage += table_size; return 0; } #ifdef CONFIG_MEMORY_HOTPLUG static void free_page_ext(void *addr) { if (is_vmalloc_addr(addr)) { vfree(addr); } else { struct page *page = virt_to_page(addr); size_t table_size; table_size = sizeof(struct page_ext) * PAGES_PER_SECTION; BUG_ON(PageReserved(page)); free_pages_exact(addr, table_size); } } static void __free_page_ext(unsigned long pfn) { struct mem_section *ms; struct page_ext *base; ms = __pfn_to_section(pfn); if (!ms || !ms->page_ext) return; base = ms->page_ext + pfn; free_page_ext(base); ms->page_ext = NULL; } static int __meminit online_page_ext(unsigned long start_pfn, unsigned long nr_pages, int nid) { unsigned long start, end, pfn; int fail = 0; start = SECTION_ALIGN_DOWN(start_pfn); end = SECTION_ALIGN_UP(start_pfn + nr_pages); if (nid == -1) { /* * In this case, "nid" already exists and contains valid memory. * "start_pfn" passed to us is a pfn which is an arg for * online__pages(), and start_pfn should exist. */ nid = pfn_to_nid(start_pfn); VM_BUG_ON(!node_state(nid, N_ONLINE)); } for (pfn = start; !fail && pfn < end; pfn += PAGES_PER_SECTION) { if (!pfn_present(pfn)) continue; fail = init_section_page_ext(pfn, nid); } if (!fail) return 0; /* rollback */ for (pfn = start; pfn < end; pfn += PAGES_PER_SECTION) __free_page_ext(pfn); return -ENOMEM; } static int __meminit offline_page_ext(unsigned long start_pfn, unsigned long nr_pages, int nid) { unsigned long start, end, pfn; start = SECTION_ALIGN_DOWN(start_pfn); end = SECTION_ALIGN_UP(start_pfn + nr_pages); for (pfn = start; pfn < end; pfn += PAGES_PER_SECTION) __free_page_ext(pfn); return 0; } static int __meminit page_ext_callback(struct notifier_block *self, unsigned long action, void *arg) { struct memory_notify *mn = arg; int ret = 0; switch (action) { case MEM_GOING_ONLINE: ret = online_page_ext(mn->start_pfn, mn->nr_pages, mn->status_change_nid); break; case MEM_OFFLINE: offline_page_ext(mn->start_pfn, mn->nr_pages, mn->status_change_nid); break; case MEM_CANCEL_ONLINE: offline_page_ext(mn->start_pfn, mn->nr_pages, mn->status_change_nid); break; case MEM_GOING_OFFLINE: break; case MEM_ONLINE: case MEM_CANCEL_OFFLINE: break; } return notifier_from_errno(ret); } #endif void __init page_ext_init(void) { unsigned long pfn; int nid; if (!invoke_need_callbacks()) return; for_each_node_state(nid, N_MEMORY) { unsigned long start_pfn, end_pfn; start_pfn = node_start_pfn(nid); end_pfn = node_end_pfn(nid); /* * start_pfn and end_pfn may not be aligned to SECTION and the * page->flags of out of node pages are not initialized. So we * scan [start_pfn, the biggest section's pfn < end_pfn) here. */ for (pfn = start_pfn; pfn < end_pfn; pfn = ALIGN(pfn + 1, PAGES_PER_SECTION)) { if (!pfn_valid(pfn)) continue; /* * Nodes's pfns can be overlapping. * We know some arch can have a nodes layout such as * -------------pfn--------------> * N0 | N1 | N2 | N0 | N1 | N2|.... * * Take into account DEFERRED_STRUCT_PAGE_INIT. */ if (early_pfn_to_nid(pfn) != nid) continue; if (init_section_page_ext(pfn, nid)) goto oom; } } hotplug_memory_notifier(page_ext_callback, 0); pr_info("allocated %ld bytes of page_ext\n", total_usage); invoke_init_callbacks(); return; oom: panic("Out of memory"); } void __meminit pgdat_page_ext_init(struct pglist_data *pgdat) { } #endif