From: Nick Piggin The bootmem code added to page_alloc.c duplicated some page freeing code that it really doesn't need to because it is not so performance critical. While we're here, make prefetching work properly by actually prefetching the page we're about to use before prefetching ahead to the next one (ie. get the most important transaction started first). Also prefetch just a single page ahead rather than leaving a gap of 16. Jack Steiner reported no problems with SGI's ia64 simulator. Signed-off-by: Nick Piggin Signed-off-by: Andrew Morton --- mm/page_alloc.c | 21 +++++++-------------- 1 files changed, 7 insertions(+), 14 deletions(-) diff -puN mm/page_alloc.c~mm-cleanup-bootmem mm/page_alloc.c --- devel/mm/page_alloc.c~mm-cleanup-bootmem 2006-01-23 00:23:50.000000000 -0800 +++ devel-akpm/mm/page_alloc.c 2006-01-23 00:23:50.000000000 -0800 @@ -55,8 +55,6 @@ unsigned long totalhigh_pages __read_mos long nr_swap_pages; int percpu_pagelist_fraction; -static void fastcall free_hot_cold_page(struct page *page, int cold); - /* * results with 256, 32 in the lowmem_reserve sysctl: * 1G machine -> (16M dma, 800M-16M normal, 1G-800M high) @@ -444,28 +442,23 @@ void fastcall __init __free_pages_bootme if (order == 0) { __ClearPageReserved(page); set_page_count(page, 0); - - free_hot_cold_page(page, 0); + set_page_refs(page, 0); + __free_page(page); } else { - LIST_HEAD(list); int loop; + prefetchw(page); for (loop = 0; loop < BITS_PER_LONG; loop++) { struct page *p = &page[loop]; - if (loop + 16 < BITS_PER_LONG) - prefetchw(p + 16); + if (loop + 1 < BITS_PER_LONG) + prefetchw(p + 1); __ClearPageReserved(p); set_page_count(p, 0); } - arch_free_page(page, order); - - mod_page_state(pgfree, 1 << order); - - list_add(&page->lru, &list); - kernel_map_pages(page, 1 << order, 0); - free_pages_bulk(page_zone(page), 1, &list, order); + set_page_refs(page, order); + __free_pages(page, order); } } _