From ff7925848b50050732ac0401e0acf27e8b241d7b Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Wed, 9 Mar 2016 15:22:55 +0000 Subject: arm64: hugetlb: partial revert of 66b3923a1a0f Commit 66b3923a1a0f ("arm64: hugetlb: add support for PTE contiguous bit") introduced support for huge pages using the contiguous bit in the PTE as opposed to block mappings, which may be slightly unwieldy (512M) in 64k page configurations. Unfortunately, this support has resulted in some late regressions when running the libhugetlbfs test suite with 64k pages and CONFIG_DEBUG_VM as a result of a BUG: | readback (2M: 64): ------------[ cut here ]------------ | kernel BUG at fs/hugetlbfs/inode.c:446! | Internal error: Oops - BUG: 0 [#1] SMP | Modules linked in: | CPU: 7 PID: 1448 Comm: readback Not tainted 4.5.0-rc7 #148 | Hardware name: linux,dummy-virt (DT) | task: fffffe0040964b00 ti: fffffe00c2668000 task.ti: fffffe00c2668000 | PC is at remove_inode_hugepages+0x44c/0x480 | LR is at remove_inode_hugepages+0x264/0x480 Rather than revert the entire patch, simply avoid advertising the contiguous huge page sizes for now while people are actively working on a fix. This patch can then be reverted once things have been sorted out. Cc: David Woods Reported-by: Steve Capper Signed-off-by: Will Deacon --- arch/arm64/mm/hugetlbpage.c | 14 -------------- 1 file changed, 14 deletions(-) diff --git a/arch/arm64/mm/hugetlbpage.c b/arch/arm64/mm/hugetlbpage.c index 82d607c3614e..da30529bb1f6 100644 --- a/arch/arm64/mm/hugetlbpage.c +++ b/arch/arm64/mm/hugetlbpage.c @@ -306,10 +306,6 @@ static __init int setup_hugepagesz(char *opt) hugetlb_add_hstate(PMD_SHIFT - PAGE_SHIFT); } else if (ps == PUD_SIZE) { hugetlb_add_hstate(PUD_SHIFT - PAGE_SHIFT); - } else if (ps == (PAGE_SIZE * CONT_PTES)) { - hugetlb_add_hstate(CONT_PTE_SHIFT); - } else if (ps == (PMD_SIZE * CONT_PMDS)) { - hugetlb_add_hstate((PMD_SHIFT + CONT_PMD_SHIFT) - PAGE_SHIFT); } else { pr_err("hugepagesz: Unsupported page size %lu K\n", ps >> 10); return 0; @@ -317,13 +313,3 @@ static __init int setup_hugepagesz(char *opt) return 1; } __setup("hugepagesz=", setup_hugepagesz); - -#ifdef CONFIG_ARM64_64K_PAGES -static __init int add_default_hugepagesz(void) -{ - if (size_to_hstate(CONT_PTES * PAGE_SIZE) == NULL) - hugetlb_add_hstate(CONT_PMD_SHIFT); - return 0; -} -arch_initcall(add_default_hugepagesz); -#endif -- cgit v1.2.3-59-g8ed1b