From d2f491e97e49d4822b402cc84b9fe081c6de15af Mon Sep 17 00:00:00 2001 From: "David S. Miller" Date: Mon, 28 Aug 2006 00:33:03 -0700 Subject: [PATCH] [SPARC64]: Fix X server hangs due to large pages. This problem was introduced by changeset 7a079eec3da50759cac67bee01f5a8d0fa75dfcf Unlike the hugetlb code paths, the normal fault code is not setup to propagate PTE changes for large page sizes correctly like the ones we make for I/O mappings in io_remap_pfn_range(). It is absolutely necessary to update all sub-ptes of a largepage mapping on a fault. Adding special handling for this would add considerably complexity to tlb_batch_add(). So let's just side-step the issue and forcefully dirty any writable PTEs created by io_remap_pfn_range(). The only other real option would be to disable to large PTE code of io_remap_pfn_range() and we really don't want to do that. Much thanks to Mikael Pettersson for tracking down this problem and testing debug patches. Signed-off-by: David S. Miller --- arch/sparc64/mm/generic.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/sparc64/mm/generic.c b/arch/sparc64/mm/generic.c index 8cb06205d2653..af9d81db0b389 100644 --- a/arch/sparc64/mm/generic.c +++ b/arch/sparc64/mm/generic.c @@ -69,6 +69,8 @@ static inline void io_remap_pte_range(struct mm_struct *mm, pte_t * pte, } else offset += PAGE_SIZE; + if (pte_write(entry)) + entry = pte_mkdirty(entry); do { BUG_ON(!pte_none(*pte)); set_pte_at(mm, address, pte, entry); -- 2.39.5