Messages in this thread Patch in this message | | | From | Mel Gorman <> | Subject | [PATCH 09/14] mm: meminit: Minimise number of pfn->page lookups during initialisation | Date | Mon, 13 Apr 2015 11:17:01 +0100 |
| |
Deferred memory initialisation is using pfn_to_page() on every PFN unnecessarily. This patch minimises the number of lookups and scheduler checks.
Signed-off-by: Mel Gorman <mgorman@suse.de> --- mm/page_alloc.c | 29 ++++++++++++++++++++++++----- 1 file changed, 24 insertions(+), 5 deletions(-)
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 10ba841c7609..21bb818aa3c4 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1077,6 +1077,7 @@ void __defermem_init deferred_init_memmap(int nid) for_each_mem_pfn_range(i, nid, &walk_start, &walk_end, NULL) { unsigned long pfn, end_pfn; + struct page *page = NULL; end_pfn = min(walk_end, zone_end_pfn(zone)); pfn = first_init_pfn; @@ -1086,13 +1087,32 @@ void __defermem_init deferred_init_memmap(int nid) pfn = zone->zone_start_pfn; for (; pfn < end_pfn; pfn++) { - struct page *page; - - if (!pfn_valid(pfn)) + if (!pfn_valid_within(pfn)) continue; - if (!meminit_pfn_in_nid(pfn, nid, &nid_init_state)) + /* + * Ensure pfn_valid is checked every + * MAX_ORDER_NR_PAGES for memory holes + */ + if ((pfn & (MAX_ORDER_NR_PAGES - 1)) == 0) { + if (!pfn_valid(pfn)) { + page = NULL; + continue; + } + } + + if (!meminit_pfn_in_nid(pfn, nid, &nid_init_state)) { + page = NULL; continue; + } + + /* Minimise pfn page lookups and scheduler checks */ + if (page && (pfn & (MAX_ORDER_NR_PAGES - 1)) != 0) { + page++; + } else { + page = pfn_to_page(pfn); + cond_resched(); + } if (page->flags) { VM_BUG_ON(page_zone(page) != zone); @@ -1101,7 +1121,6 @@ void __defermem_init deferred_init_memmap(int nid) __init_single_page(page, pfn, zid, nid); __free_pages_boot_core(page, pfn, 0); - cond_resched(); } first_init_pfn = max(end_pfn, first_init_pfn); } -- 2.1.2
| |