--- a/mm/percpu-km.c +++ b/mm/percpu-km.c @@ -34,7 +34,7 @@ #include static int pcpu_populate_chunk(struct pcpu_chunk *chunk, - int page_start, int page_end) + int page_start, int page_end, gfp_t gfp) { return 0; } @@ -45,18 +45,18 @@ static void pcpu_depopulate_chunk(struct pcpu_chunk *chunk, /* nada */ } -static struct pcpu_chunk *pcpu_create_chunk(void) +static struct pcpu_chunk *pcpu_create_chunk(gfp_t gfp) { const int nr_pages = pcpu_group_sizes[0] >> PAGE_SHIFT; struct pcpu_chunk *chunk; struct page *pages; int i; - chunk = pcpu_alloc_chunk(); + chunk = pcpu_alloc_chunk(gfp); if (!chunk) return NULL; - pages = alloc_pages(GFP_KERNEL, order_base_2(nr_pages)); + pages = alloc_pages(gfp | GFP_KERNEL, order_base_2(nr_pages)); if (!pages) { pcpu_free_chunk(chunk); return NULL; diff --git a/mm/percpu-vm.c b/mm/percpu-vm.c index 9158e5a..ea9906a 100644 --- a/mm/percpu-vm.c +++ b/mm/percpu-vm.c @@ -37,7 +37,7 @@ static struct page **pcpu_get_pages(void) lockdep_assert_held(&pcpu_alloc_mutex); if (!pages) - pages = pcpu_mem_zalloc(pages_size); + pages = pcpu_mem_zalloc(pages_size, 0); return pages; } @@ -73,18 +73,21 @@ static void pcpu_free_pages(struct pcpu_chunk *chunk, * @pages: array to put the allocated pages into, indexed by pcpu_page_idx() * @page_start: page index of the first page to be allocated * @page_end: page index of the last page to be allocated + 1 + * @gfp: allocation flags passed to the underlying allocator * * Allocate pages [@page_start,@page_end) into @pages for all units. * The allocation is for @chunk. Percpu core doesn't care about the * content of @pages and will pass it verbatim to pcpu_map_pages(). */ static int pcpu_alloc_pages(struct pcpu_chunk *chunk, - struct page **pages, int page_start, int page_end) + struct page **pages, int page_start, int page_end, + gfp_t gfp) { - const gfp_t gfp = GFP_KERNEL | __GFP_HIGHMEM; unsigned int cpu, tcpu; int i; + gfp |= GFP_KERNEL | __GFP_HIGHMEM; + for_each_possible_cpu(cpu) { for (i = page_start; i < page_end; i++) { struct page **pagep = &pages[pcpu_page_idx(cpu, i)]; @@ -262,6 +265,7 @@ static void pcpu_post_map_flush(struct pcpu_chunk *chunk, * @chunk: chunk of interest * @page_start: the start page * @page_end: the end page + * @gfp: allocation flags passed to the underlying memory allocator * * For each cpu, populate and map pages [@page_start,@page_end) into * @chunk. @@ -270,7 +274,7 @@ static void pcpu_post_map_flush(struct pcpu_chunk *chunk, * pcpu_alloc_mutex, does GFP_KERNEL allocation. */ static int pcpu_populate_chunk(struct pcpu_chunk *chunk, - int page_start, int page_end) + int page_start, int page_end, gfp_t gfp) { struct page **pages; @@ -278,7 +282,7 @@ static int pcpu_populate_chunk(struct pcpu_chunk *chunk, if (!pages) return -ENOMEM; - if (pcpu_alloc_pages(chunk, pages, page_start, page_end)) + if (pcpu_alloc_pages(chunk, pages, page_start, page_end, gfp)) return -ENOMEM; if (pcpu_map_pages(chunk, pages, page_start, page_end)) { @@ -325,12 +329,12 @@ static void pcpu_depopulate_chunk(struct pcpu_chunk *chunk, pcpu_free_pages(chunk, pages, page_start, page_end); } -static struct pcpu_chunk *pcpu_create_chunk(void) +static struct pcpu_chunk *pcpu_create_chunk(gfp_t gfp) { struct pcpu_chunk *chunk; struct vm_struct **vms; - chunk = pcpu_alloc_chunk(); + chunk = pcpu_alloc_chunk(gfp); if (!chunk) return NULL; diff --git a/mm/percpu.c b/mm/percpu.c index 50e7fdf..ecb9193 100644 --- a/mm/percpu.c +++ b/mm/percpu.c @@ -447,10 +447,12 @@ static void pcpu_next_fit_region(struct pcpu_chunk *chunk, int alloc_bits, /** * pcpu_mem_zalloc - allocate memory * @size: bytes to allocate + * @gfp: allocation flags * * Allocate @size bytes. If @size is smaller than PAGE_SIZE, - * kzalloc() is used; otherwise, vzalloc() is used. The returned - * memory is always zeroed. + * kzalloc() is used; otherwise, the equivalent of vzalloc() is used. + * This is to facilitate passing through flags such as __GFP_NOREPLY. + * The returned memory is always zeroed. * * CONTEXT: * Does GFP_KERNEL allocation. @@ -458,15 +460,16 @@ static void pcpu_next_fit_region(struct pcpu_chunk *chunk, int alloc_bits, * RETURNS: * Pointer to the allocated area on success, NULL on failure. */ -static void *pcpu_mem_zalloc(size_t size) +static void *pcpu_mem_zalloc(size_t size, gfp_t gfp) { if (WARN_ON_ONCE(!slab_is_available())) return NULL; if (size <= PAGE_SIZE) - return kzalloc(size, GFP_KERNEL); + return kzalloc(size, gfp | GFP_KERNEL); else - return vzalloc(size); + return __vmalloc(size, gfp | GFP_KERNEL | __GFP_ZERO, + PAGE_KERNEL); } /** @@ -1154,12 +1157,12 @@ static struct pcpu_chunk * __init pcpu_alloc_first_chunk(unsigned long tmp_addr, return chunk; } -static struct pcpu_chunk *pcpu_alloc_chunk(void) +static struct pcpu_chunk *pcpu_alloc_chunk(gfp_t gfp) { struct pcpu_chunk *chunk; int region_bits; - chunk = pcpu_mem_zalloc(pcpu_chunk_struct_size); + chunk = pcpu_mem_zalloc(pcpu_chunk_struct_size, gfp); if (!chunk) return NULL; @@ -1168,17 +1171,17 @@ static struct pcpu_chunk *pcpu_alloc_chunk(void) region_bits = pcpu_chunk_map_bits(chunk); chunk->alloc_map = pcpu_mem_zalloc(BITS_TO_LONGS(region_bits) * - sizeof(chunk->alloc_map[0])); + sizeof(chunk->alloc_map[0]), gfp); if (!chunk->alloc_map) goto alloc_map_fail; chunk->bound_map = pcpu_mem_zalloc(BITS_TO_LONGS(region_bits + 1) * - sizeof(chunk->bound_map[0])); + sizeof(chunk->bound_map[0]), gfp); if (!chunk->bound_map) goto bound_map_fail; chunk->md_blocks = pcpu_mem_zalloc(pcpu_chunk_nr_blocks(chunk) * - sizeof(chunk->md_blocks[0])); + sizeof(chunk->md_blocks[0]), gfp); if (!chunk->md_blocks) goto md_blocks_fail; @@ -1277,9 +1280,10 @@ static void pcpu_chunk_depopulated(struct pcpu_chunk *chunk, * pcpu_addr_to_page - translate address to physical address * pcpu_verify_alloc_info - check alloc_info is acceptable during init */ -static int pcpu_populate_chunk(struct pcpu_chunk *chunk, int off, int size); +static int pcpu_populate_chunk(struct pcpu_chunk *chunk, int off, int size, + gfp_t gfp); static void pcpu_depopulate_chunk(struct pcpu_chunk *chunk, int off, int size); -static struct pcpu_chunk *pcpu_create_chunk(void); +static struct pcpu_chunk *pcpu_create_chunk(gfp_t gfp); static void pcpu_destroy_chunk(struct pcpu_chunk *chunk); static struct page *pcpu_addr_to_page(void *addr); static int __init pcpu_verify_alloc_info(const struct pcpu_alloc_info *ai); @@ -1421,7 +1425,7 @@ static void __percpu *pcpu_alloc(size_t size, size_t align, bool reserved, } if (list_empty(&pcpu_slot[pcpu_nr_slots - 1])) { - chunk = pcpu_create_chunk(); + chunk = pcpu_create_chunk(0); if (!chunk) { err = "failed to allocate new chunk"; goto fail; @@ -1450,7 +1454,7 @@ static void __percpu *pcpu_alloc(size_t size, size_t align, bool reserved, page_start, page_end) { WARN_ON(chunk->immutable); - ret = pcpu_populate_chunk(chunk, rs, re); + ret = pcpu_populate_chunk(chunk, rs, re, 0); spin_lock_irqsave(&pcpu_lock, flags); if (ret) { @@ -1561,10 +1565,17 @@ void __percpu *__alloc_reserved_percpu(size_t size, size_t align) * pcpu_balance_workfn - manage the amount of free chunks and populated pages * @work: unused * - * Reclaim all fully free chunks except for the first one. + * Reclaim all fully free chunks except for the first one. This is also + * responsible for maintaining the pool of empty populated pages. However, + * it is possible that this is called when physical memory is scarce causing + * OOM killer to be triggered. We should avoid doing so until an actual + * allocation causes the failure as it is possible that requests can be + * serviced from already backed regions. */ static void pcpu_balance_workfn(struct work_struct *work) { + /* gfp flags passed to underlying allocators */ + gfp_t gfp = __GFP_NOWARN | __GFP_NORETRY; LIST_HEAD(to_free); struct list_head *free_head = &pcpu_slot[pcpu_nr_slots - 1]; struct pcpu_chunk *chunk, *next; @@ -1645,7 +1656,7 @@ static void pcpu_balance_workfn(struct work_struct *work) chunk->nr_pages) { int nr = min(re - rs, nr_to_pop); - ret = pcpu_populate_chunk(chunk, rs, rs + nr); + ret = pcpu_populate_chunk(chunk, rs, rs + nr, gfp); if (!ret) { nr_to_pop -= nr; spin_lock_irq(&pcpu_lock); @@ -1662,7 +1673,7 @@ static void pcpu_balance_workfn(struct work_struct *work) if (nr_to_pop) { /* ran out of chunks to populate, create a new one and retry */ - chunk = pcpu_create_chunk(); + chunk = pcpu_create_chunk(gfp); if (chunk) { spin_lock_irq(&pcpu_lock); pcpu_chunk_relocate(chunk, -1);