From 41546c17418fba08ece978bad72a33072715b8f3 Mon Sep 17 00:00:00 2001 From: Johannes Weiner Date: Wed, 23 Jul 2008 21:28:03 -0700 Subject: [PATCH] bootmem: clean up free_all_bootmem_core Rewrite the code in a more concise way using less variables. [akpm@linux-foundation.org: fix printk warnings] Signed-off-by: Johannes Weiner Cc: Ingo Molnar Cc: Yinghai Lu Cc: Andi Kleen Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/bootmem.c | 83 ++++++++++++++++++++++++---------------------------- 1 file changed, 38 insertions(+), 45 deletions(-) diff --git a/mm/bootmem.c b/mm/bootmem.c index 9da7d4097810..300d126ec533 100644 --- a/mm/bootmem.c +++ b/mm/bootmem.c @@ -144,66 +144,59 @@ unsigned long __init init_bootmem(unsigned long start, unsigned long pages) static unsigned long __init free_all_bootmem_core(bootmem_data_t *bdata) { + int aligned; struct page *page; - unsigned long pfn; - unsigned long i, count; - unsigned long idx, pages; - unsigned long *map; - int gofast = 0; + unsigned long start, end, pages, count = 0; - BUG_ON(!bdata->node_bootmem_map); + if (!bdata->node_bootmem_map) + return 0; + + start = PFN_DOWN(bdata->node_boot_start); + end = bdata->node_low_pfn; - count = 0; - /* first extant page of the node */ - pfn = PFN_DOWN(bdata->node_boot_start); - idx = bdata->node_low_pfn - pfn; - map = bdata->node_bootmem_map; /* - * Check if we are aligned to BITS_PER_LONG pages. If so, we might - * be able to free page orders of that size at once. + * If the start is aligned to the machines wordsize, we might + * be able to free pages in bulks of that order. */ - if (!(pfn & (BITS_PER_LONG-1))) - gofast = 1; + aligned = !(start & (BITS_PER_LONG - 1)); - for (i = 0; i < idx; ) { - unsigned long v = ~map[i / BITS_PER_LONG]; + bdebug("nid=%td start=%lx end=%lx aligned=%d\n", + bdata - bootmem_node_data, start, end, aligned); - if (gofast && v == ~0UL) { - int order; + while (start < end) { + unsigned long *map, idx, vec; - page = pfn_to_page(pfn); + map = bdata->node_bootmem_map; + idx = start - PFN_DOWN(bdata->node_boot_start); + vec = ~map[idx / BITS_PER_LONG]; + + if (aligned && vec == ~0UL && start + BITS_PER_LONG < end) { + int order = ilog2(BITS_PER_LONG); + + __free_pages_bootmem(pfn_to_page(start), order); count += BITS_PER_LONG; - order = ffs(BITS_PER_LONG) - 1; - __free_pages_bootmem(page, order); - i += BITS_PER_LONG; - page += BITS_PER_LONG; - } else if (v) { - unsigned long m; - - page = pfn_to_page(pfn); - for (m = 1; m && i < idx; m<<=1, page++, i++) { - if (v & m) { - count++; - __free_pages_bootmem(page, 0); - } - } } else { - i += BITS_PER_LONG; + unsigned long off = 0; + + while (vec && off < BITS_PER_LONG) { + if (vec & 1) { + page = pfn_to_page(start + off); + __free_pages_bootmem(page, 0); + count++; + } + vec >>= 1; + off++; + } } - pfn += BITS_PER_LONG; + start += BITS_PER_LONG; } - /* - * Now free the allocator bitmap itself, it's not - * needed anymore: - */ page = virt_to_page(bdata->node_bootmem_map); pages = bdata->node_low_pfn - PFN_DOWN(bdata->node_boot_start); - idx = bootmem_bootmap_pages(pages); - for (i = 0; i < idx; i++, page++) - __free_pages_bootmem(page, 0); - count += i; - bdata->node_bootmem_map = NULL; + pages = bootmem_bootmap_pages(pages); + count += pages; + while (pages--) + __free_pages_bootmem(page++, 0); bdebug("nid=%td released=%lx\n", bdata - bootmem_node_data, count);