Commit-ID: bd2753b2dda7bb43c7468826de75f49c6a7e8965 Gitweb: http://git.kernel.org/tip/bd2753b2dda7bb43c7468826de75f49c6a7e8965 Author: Yinghai Lu <yinghai@xxxxxxxxxx> AuthorDate: Wed, 6 Jun 2012 10:55:40 -0700 Committer: Ingo Molnar <mingo@xxxxxxxxxx> CommitDate: Fri, 8 Jun 2012 11:40:50 +0200 x86/mm: Only add extra pages count for the first memory range during pre-allocation early page table space Robin found this regression: | I just tried to boot an 8TB system. It fails very early in boot with: | Kernel panic - not syncing: Cannot find space for the kernel page tables git bisect commit 722bc6b16771ed80871e1fd81c86d3627dda2ac8. A git revert of that commit does boot past that point on the 8TB configuration. That commit will add up extra pages for all memory range even above 4g. Try to limit that extra page count adding to first entry only. Bisected-by: Robin Holt <holt@xxxxxxx> Tested-by: Robin Holt <holt@xxxxxxx> Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx> Cc: WANG Cong <xiyou.wangcong@xxxxxxxxx> Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx> Link: http://lkml.kernel.org/r/CAE9FiQUj3wyzQxtq9yzBNc9u220p8JZ1FYHG7t%3DMOzJ%3D9BZMYA@xxxxxxxxxxxxxx Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> --- arch/x86/mm/init.c | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-) diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c index 97141c2..bc4e9d8 100644 --- a/arch/x86/mm/init.c +++ b/arch/x86/mm/init.c @@ -62,7 +62,8 @@ static void __init find_early_table_space(struct map_range *mr, unsigned long en extra += PMD_SIZE; #endif /* The first 2/4M doesn't use large pages. */ - extra += mr->end - mr->start; + if (mr->start < PMD_SIZE) + extra += mr->end - mr->start; ptes = (extra + PAGE_SIZE - 1) >> PAGE_SHIFT; } else -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html