Joshua reported: Commit cd7b304dfaf1 (x86, range: fix missing merge during add range) broke mtrr cleanup on his setup in 3.9.5. corresponding commit in upstream is fbe06b7bae7c. *BAD*gran_size: 64K chunk_size: 16M num_reg: 6 lose cover RAM: -0G https://bugzilla.kernel.org/show_bug.cgi?id=59491 So it rejects new var mtrr layout. It turns out we have some problem with initial mtrr range retrievel. current sequence is: x86_get_mtrr_mem_range ==> bunchs of add_range_with_merge ==> bunchs of subract_range ==> clean_sort_range add_range_with_merge for [0,1M) sort_range() add_range_with_merge could have blank slots, so we can not just sort only, that will have final result have extra blank slot in head. So move that calling add_range_with_merge for [0,1M), with that we could avoid extra clean_sort_range calling. Reported-by: Joshua Covington <joshuacov@xxxxxxxxxxxxxx> Tested-by: Joshua Covington <joshuacov@xxxxxxxxxxxxxx> Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> v3.9 --- arch/x86/kernel/cpu/mtrr/cleanup.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) Index: linux-2.6/arch/x86/kernel/cpu/mtrr/cleanup.c =================================================================== --- linux-2.6.orig/arch/x86/kernel/cpu/mtrr/cleanup.c +++ linux-2.6/arch/x86/kernel/cpu/mtrr/cleanup.c @@ -714,15 +714,15 @@ int __init mtrr_cleanup(unsigned address if (mtrr_tom2) x_remove_size = (mtrr_tom2 >> PAGE_SHIFT) - x_remove_base; - nr_range = x86_get_mtrr_mem_range(range, 0, x_remove_base, x_remove_size); /* * [0, 1M) should always be covered by var mtrr with WB * and fixed mtrrs should take effect before var mtrr for it: */ - nr_range = add_range_with_merge(range, RANGE_NUM, nr_range, 0, + nr_range = add_range_with_merge(range, RANGE_NUM, 0, 0, 1ULL<<(20 - PAGE_SHIFT)); - /* Sort the ranges: */ - sort_range(range, nr_range); + /* add from var mtrr at last */ + nr_range = x86_get_mtrr_mem_range(range, nr_range, + x_remove_base, x_remove_size); range_sums = sum_ranges(range, nr_range); printk(KERN_INFO "total RAM covered: %ldM\n", -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html