From 35fd1eb1e8212c02f6eae24335a9e5b80f9519b4 Mon Sep 17 00:00:00 2001 From: Pavel Tatashin Date: Fri, 17 Aug 2018 15:49:21 -0700 Subject: [PATCH] mm/sparse: abstract sparse buffer allocations MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Patch series "sparse_init rewrite", v6. In sparse_init() we allocate two large buffers to temporary hold usemap and memmap for the whole machine. However, we can avoid doing that if we changed sparse_init() to operated on per-node bases instead of doing it on the whole machine beforehand. As shown by Baoquan http://lkml.kernel.org/r/20180628062857.29658-1-bhe@redhat.com The buffers are large enough to cause machine stop to boot on small memory systems. Another benefit of these changes is that they also obsolete CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER. This patch (of 5): When struct pages are allocated for sparse-vmemmap VA layout, we first try to allocate one large buffer, and than if that fails allocate struct pages for each section as we go. The code that allocates buffer is uses global variables and is spread across several call sites. Cleanup the code by introducing three functions to handle the global buffer: sparse_buffer_init() initialize the buffer sparse_buffer_fini() free the remaining part of the buffer sparse_buffer_alloc() alloc from the buffer, and if buffer is empty return NULL Define these functions in sparse.c instead of sparse-vmemmap.c because later we will use them for non-vmemmap sparse allocations as well. [akpm@linux-foundation.org: use PTR_ALIGN()] [akpm@linux-foundation.org: s/BUG_ON/WARN_ON/] Link: http://lkml.kernel.org/r/20180712203730.8703-2-pasha.tatashin@oracle.com Signed-off-by: Pavel Tatashin Tested-by: Michael Ellerman [powerpc] Reviewed-by: Oscar Salvador Tested-by: Oscar Salvador Cc: Pasha Tatashin Cc: Steven Sistare Cc: Daniel Jordan Cc: "Kirill A. Shutemov" Cc: Michal Hocko Cc: Dan Williams Cc: Jan Kara Cc: Jérôme Glisse Cc: Souptick Joarder Cc: Baoquan He Cc: Greg Kroah-Hartman Cc: Vlastimil Babka Cc: Wei Yang Cc: Dave Hansen Cc: David Rientjes Cc: Ingo Molnar Cc: Abdul Haleem Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/mm.h | 4 ++++ mm/sparse-vmemmap.c | 40 ++++++---------------------------------- mm/sparse.c | 45 ++++++++++++++++++++++++++++++++++++++++++++- 3 files changed, 54 insertions(+), 35 deletions(-) diff --git a/include/linux/mm.h b/include/linux/mm.h index 2fb32d1561eb..4ace5d50a892 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -2671,6 +2671,10 @@ void sparse_mem_maps_populate_node(struct page **map_map, unsigned long map_count, int nodeid); +unsigned long __init section_map_size(void); +void sparse_buffer_init(unsigned long size, int nid); +void sparse_buffer_fini(void); +void *sparse_buffer_alloc(unsigned long size); struct page *sparse_mem_map_populate(unsigned long pnum, int nid, struct vmem_altmap *altmap); pgd_t *vmemmap_pgd_populate(unsigned long addr, int node); diff --git a/mm/sparse-vmemmap.c b/mm/sparse-vmemmap.c index 95e2c7638a5c..b05c7663c640 100644 --- a/mm/sparse-vmemmap.c +++ b/mm/sparse-vmemmap.c @@ -43,12 +43,9 @@ static void * __ref __earlyonly_bootmem_alloc(int node, unsigned long goal) { return memblock_virt_alloc_try_nid_raw(size, align, goal, - BOOTMEM_ALLOC_ACCESSIBLE, node); + BOOTMEM_ALLOC_ACCESSIBLE, node); } -static void *vmemmap_buf; -static void *vmemmap_buf_end; - void * __meminit vmemmap_alloc_block(unsigned long size, int node) { /* If the main allocator is up use that, fallback to bootmem. */ @@ -76,18 +73,10 @@ void * __meminit vmemmap_alloc_block(unsigned long size, int node) /* need to make sure size is all the same during early stage */ void * __meminit vmemmap_alloc_block_buf(unsigned long size, int node) { - void *ptr; - - if (!vmemmap_buf) - return vmemmap_alloc_block(size, node); - - /* take the from buf */ - ptr = (void *)ALIGN((unsigned long)vmemmap_buf, size); - if (ptr + size > vmemmap_buf_end) - return vmemmap_alloc_block(size, node); - - vmemmap_buf = ptr + size; + void *ptr = sparse_buffer_alloc(size); + if (!ptr) + ptr = vmemmap_alloc_block(size, node); return ptr; } @@ -279,19 +268,9 @@ void __init sparse_mem_maps_populate_node(struct page **map_map, unsigned long map_count, int nodeid) { unsigned long pnum; - unsigned long size = sizeof(struct page) * PAGES_PER_SECTION; - void *vmemmap_buf_start; int nr_consumed_maps = 0; - size = ALIGN(size, PMD_SIZE); - vmemmap_buf_start = __earlyonly_bootmem_alloc(nodeid, size * map_count, - PMD_SIZE, __pa(MAX_DMA_ADDRESS)); - - if (vmemmap_buf_start) { - vmemmap_buf = vmemmap_buf_start; - vmemmap_buf_end = vmemmap_buf_start + size * map_count; - } - + sparse_buffer_init(section_map_size() * map_count, nodeid); for (pnum = pnum_begin; pnum < pnum_end; pnum++) { if (!present_section_nr(pnum)) continue; @@ -303,12 +282,5 @@ void __init sparse_mem_maps_populate_node(struct page **map_map, pr_err("%s: sparsemem memory map backing failed some memory will not be available\n", __func__); } - - if (vmemmap_buf_start) { - /* need to free left buf */ - memblock_free_early(__pa(vmemmap_buf), - vmemmap_buf_end - vmemmap_buf); - vmemmap_buf = NULL; - vmemmap_buf_end = NULL; - } + sparse_buffer_fini(); } diff --git a/mm/sparse.c b/mm/sparse.c index 2ea8b3dbd0df..9a0a5f598469 100644 --- a/mm/sparse.c +++ b/mm/sparse.c @@ -400,7 +400,14 @@ static void __init sparse_early_usemaps_alloc_node(void *data, } } -#ifndef CONFIG_SPARSEMEM_VMEMMAP +#ifdef CONFIG_SPARSEMEM_VMEMMAP +unsigned long __init section_map_size(void) + +{ + return ALIGN(sizeof(struct page) * PAGES_PER_SECTION, PMD_SIZE); +} + +#else struct page __init *sparse_mem_map_populate(unsigned long pnum, int nid, struct vmem_altmap *altmap) { @@ -457,6 +464,42 @@ void __init sparse_mem_maps_populate_node(struct page **map_map, } #endif /* !CONFIG_SPARSEMEM_VMEMMAP */ +static void *sparsemap_buf __meminitdata; +static void *sparsemap_buf_end __meminitdata; + +void __init sparse_buffer_init(unsigned long size, int nid) +{ + WARN_ON(sparsemap_buf); /* forgot to call sparse_buffer_fini()? */ + sparsemap_buf = + memblock_virt_alloc_try_nid_raw(size, PAGE_SIZE, + __pa(MAX_DMA_ADDRESS), + BOOTMEM_ALLOC_ACCESSIBLE, nid); + sparsemap_buf_end = sparsemap_buf + size; +} + +void __init sparse_buffer_fini(void) +{ + unsigned long size = sparsemap_buf_end - sparsemap_buf; + + if (sparsemap_buf && size > 0) + memblock_free_early(__pa(sparsemap_buf), size); + sparsemap_buf = NULL; +} + +void * __meminit sparse_buffer_alloc(unsigned long size) +{ + void *ptr = NULL; + + if (sparsemap_buf) { + ptr = PTR_ALIGN(sparsemap_buf, size); + if (ptr + size > sparsemap_buf_end) + ptr = NULL; + else + sparsemap_buf = ptr + size; + } + return ptr; +} + #ifdef CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER static void __init sparse_early_mem_maps_alloc_node(void *data, unsigned long pnum_begin,